CIVIL ENGINEERING SEMINAR TOPICS

LIST OF SEMINARS

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ENVIRONMENTAL ENGINEERING M.TECH SEMINAR

MODERN METHODS OF CONSTRUCTION

2017-01-11T10:15:00.001-08:00

By JAINRAJ

Page 1

CHAPTER 1

INTRODUCTION

Modern methods of construction are about better products and processes. They aim to improve business efficiency, quality, customer satisfaction, environmental performance, sustainability and the predictability of delivery timescales. Modern methods of construction are, therefore, more broadly based than a particular focus on product.

They engage people and process to seek improvement in the delivery and performance of construction, modern methods of construction are about better products and processes. They aim to improve business efficiency, quality, customer satisfaction, environmental performance, sustainability and the predictability of delivery timescales. Modern methods of construction are, therefore, more broadly based than a particular focus on product. They engage people and process to seek improvement in the delivery and performance of construction

With developments in technology, general construction knowledge and manufacturing processes, Modern construction technology have evolved from the more conventional methods to a large extent. Modern construction technology can be defined as those that provide greater efficiency in the construction process, resulting in increased production, better quality, in less time and with less waste, so reducing the environmental impact. MMC is a process to produce more, better quality homes in less time.

Modern construction technology is a collective term used to describe a number of construction methods. The methods being introduced into the world house building differ significantly from so-called conventional construction methods such as brick and block.

In this report, we use the term MMC. This is because this term is increasingly being used and because it also includes several important new types of construction methods that involve some element of fabrication on site.

Advanced technologies in housing construction are not used as frequently as the more standard construction technologies, which involve the use of masonry, timber, and concrete. However, as with other innovations, it is expected that over time these newer technologies will gain wider acceptance. For purposes of the World Housing Encyclopedia, advanced technologies include seismic isolation and passive-energy dissipation devices.

MMC are about better products and processes. They aim to improve business efficiency, quality, customer satisfaction, environmental performance, sustainability and the predictability of delivery timescales. Modern methods of construction are, therefore, more broadly based than a particular focus on product. They engage people and process to seek improvement in the delivery and performance of construction.

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MODERN METHODS OF CONSTRUCTION (Page 2)

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CHAPTER 2

ADVANTAGES

2.1. Quicker on site build time/shorter programmes/reduced preliminaries:

With MMC, much of the work is removed from the site and it is therefore possible to execute various activities of the project concurrently or even before the project has commenced on site. This reduces the projects construction time as the building or elements of the building can be manufactured off site while the ground and site works are taking place. MMC leads to a reduction in trades on site and a shorter construction programme which in turn leads to reduced preliminaries, overheads and a quicker return on investment for the client.

2.2. Reduced waste and better waste management:

As production is often executed in a factory controlled environment, the waste stream can be easier to manage. Exact quantities of materials can be purchased, materials can be used more efficiently and because materials are properly stored, breakages and damage are less likely to occur. Furthermore any un-used materials can be easily collected, re-used or recycled contributing to less waste. Constant monitoring also takes place within a production plant allowing new waste management strategies to be implemented without difficulty, if necessary. Waste reduction is a very significant advantage as waste from construction is one of the principle waste streams to landfills and it has been proven that a high percentage of materials delivered to site are never even used and go straight into the waste cycle.

2.3. Reduction in defects and increased quality control:

As you can imagine, a building site in Ireland, fully exposed to our rainy and windy climate is not exactly the perfect working environment for high quality workmanship.

Construction work exposed to the elements of wind and rain proves more difficult to monitor with regard to quality control. Human error is also another significant factor which deters the achievement of high quality construction as it can prove difficult to work in extreme weather conditions.

Factory based constructions forms, engage better and safer working conditions with no interference by the Irish climate and therefore a very high standard of quality control can be achieved which includes testing, trials, checks and re-checks. For more reasons than one, factory based construction provides better working conditions than a building site and in turn produces better quality too.

2.4. Increased Health & Safety:

Construction work carried out in a factory controlled environment is without doubt a safer working environment for all trades. Safety controls are implemented and monitored and safe working conditions are easier to meet and maintain. With off-site construction there is a significant reduction in the number of trades working on site and this proves more manageable from a health and safety perspective. Construction work on site can incorporate some very dangerous activities and in turn lead to a large number of causalities and/or fatal injuries. Construction is among the largest number of fatal injuries between all the main industries in Ireland. Statistics from 2002 to 2009 (as seen in Appendix A) show that the construction sector has been either the first or second largest contributor to fatal injuries in the past 8 years.

2.5. Social benefits and reduced local impacts:

MMC’s and in particular off-site construction, allow local communities to benefit from the process of manufacturing away from site. The main advantage to communities is that there is much less traffic and smaller on site work forces adding to traffic congestion in the area. Furthermore due to speedier on-site programmes, noise and pollution levels will decrease and the locality surrounding the site will be disrupted for a far shorter period of time.

Construction sites are only temporary employment locations and offer little or no amenities for the local communities whereas manufacturing facilities very often provide long term social services and economic benefits for the surrounding community. Manufacturing facilities are also more likely to invest in education and training for their workforce and develop a highly trained local workforce within their facility.

2.6. Greater efficiency in the use of resources and transport

Over the years it has been noted that the use of labour, plant and materials on building sites is extremely inefficient as is not the case with factory based activities which are kept under extreme scrutiny, monitored and controlled. Re-cycling and re-using of materials is also more difficult to enforce on a building site but is easily implemented in a factory based environment. On another note, monitoring of transport patterns and schedules can be very difficult on construction sites especially if the site is condensed and compact. With off-site MMC the number of deliveries direct to the building site is reduced and deliveries to factories can be planned and controlled so that full loads can be used and transport costs are kept to a minimum. On the other hand, transport of prefabricated or modular buildings to site must be carefully planned and heavy plant and equipment necessary for off-loading and erection requires careful site management and consideration.

CHAPTER 3

DIFFERENT TYPES OF MMC

3.1. Volumetric Construction

Three dimensional units produced in a factory fully fitted out and dropped onto foundations to form a structure e.g. bathroom or kitchen PODS.

Fig 3.1 Volumetric Construction

3.2. Panelised construction

Units produced in a factory and assembled into a three-dimensional structure on site e.g. concrete wall panels, structural insulated panels (SIPS), curtain walling etc.

Fig 3.2 Panellised construction

3.3. Hybrid construction

Volumetric construction integrated with panelised construction e.g. kitchen pod as volumetric unit with the rest of the dwelling constructed using panels.

Fig 3.3 Hybrid construction

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MODERN METHODS OF CONSTRUCTION (Page 3)

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CHAPTER 4

STRUCTURAL COMPONENTS

4.1. Precast Floor Slabs:

For this project it is proposed to use pre-stressed wide slab as will span up to 8m simply supported. This is sufficient for the development as the maximum floor span is around five and a half meters. Other options are Filigree slabs which can span 5.5 m simply supported but this type of slab is not as widely used in the industry. Hollow core flooring is another alternative but this is only really necessary for spans greater that 8 m and up to 16.5 m and the building is in excess of seven or eight floors and a lighter weight option is required. It will be necessary to prop the floor at 600 centres using acro type props with timber girders running horizontally from prop to prop.

For this structure, the proposed wide slab will have a 100 mm slab depth and a width of 2400 mm as standard will be used where possible. This shallow floor will give maximum floor-to-floor height resulting in no loss of space. It will also provide a smooth soffit finish, which can be used as a finished surface in areas where suspended ceilings are not specified i.e. the apartments. The floor slab will sit approx 70 mm into the wall panel and the slabs will also be lifted in by crane via projecting lifting hooks on the surface of the slab. A 125 mm screed over the 100 mm wide slab will be sufficient and can incorporate services into the floor if necessary. It may be possible to cast up stands on the precast walls instead of shuttering the perimeter for screeding. A393 mesh along with tie steel will be placed on the slab and a 35-40 N structural screed will be poured over this. The perimeter of the floor, opens, stairwells etc will have to be shuttered to house the screed and prevent spillages. The concrete will be pumped in using a concrete pump and all floors will receive a power float finish.

The floors will be connected to the wall panels via U bars which are wrapped around the treaded bar projecting from the panel to connect the wall directly above. Handrail will also be necessary around the perimeter and large opens. There will be a plastic leg on the handrail posts that can be left in the screed afterwards. The perimeter handrail will be moved up floor by floor as screeding progresses but handrail around opens must remain until it is safe to remove.

Fig 4.1 Precast Floor Slabs

4.2 Precast Stairs:

It is proposed to use precast stairs from basement to fourth floor. The stairs are prefabricated off site and are cast in a steel mould for manufacture. The use of precast stairs means that while they can be erected by crane with the wall and floor panels, they also allow access up the building for the precast crew as the building progresses.

Fig 4.2 Precast Stairs

4.3 Internal Finishes:

It is also proposed that a thin coat spray on plaster system will be used on the rough side of the precast walls and also on the ceilings. The material recommended for this is a thin spray on plaster known as Alltek which is supplied by International Coating Products (ICP) and who many suppliers and applicators across Ireland, the United Kingdom and Europe. The Alltek product is packaged in standard 25kg bags and comes in the form of a white powder which comes from fine graded marble. Alltek is applied in two coats and is suitable to be sprayed onto fair faced concrete surfaces, gypsum boards, smooth plastered surfaces etc. The Alltek Red Label can also be sprayed over the Alltek Blue Course plaster which is used on rough surfaces.

Alltek also supply dry fillers used to fill joints in panels, the filler is just mixed with water on site and applied to the joint. Once the joints are dried and sanded down, the walls are then ready to receive the plaster spray coat. The Alltek red label is poured into the spray machine and the applicator then commences spraying the Alltek onto the prefilled surface. The second coat of spray can only be applied once the first has fully dried out. Alltek can be applied in a flat or textured finish and in several pastel shade thus reducing painting and decorating costs. Between 200-300 m2 of two coat Alltek application can be achieved per day.

CHAPTER 5

REDUCTION IN PROGRAMME

It is my belief as the contractor that by adopting the above mentioned modern methods of construction on the South Cumberland Development we can significantly reduce the program duration for this project. Based on figures from one precast manufacturer, Alcrete Ltd, 1450m2 of precast walls can be produced in their factory in just one week. As can be seen from the below chart, this is more walls that needed for the entire development. Hence production of precast walls off-site will automatically reduce the program and even taking into account the lead in time required by the manufacturer, signification time savings can be achieved here. It must also be noted that lead in times for precast manufacturers has reduced significantly due to lack of workload in this economic downturn.

Further reductions in program duration can be achieved through erection on site of the precast elements. Further figures from Alcrete show that 325 m2 of double walls and 450 m2 of solid walls can be erected per week by a 5 man crew. In addition, 280 m2 of wide slab can be erected per day by a 4 man crew thus showing how the frame can be erected in just a number of weeks.

Furthermore with no scaffolding, drying out time, erection or dismantling of shutters/pans etc needed, the precast frame is less weather dependent than in-situ construction forms and is therefore less likely to experience delays or set backs on site. Once erection of the frame has been completed additional time savings can also be achieved in the finishes such as plastering works, mechanical and electrical works, installation of cladding etc.

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MODERN METHODS OF CONSTRUCTION (Page 4)

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CHAPTER 6

CASE STUDY

6.1 Concrete walls and floors

Concrete walls is an eclectic category with options for everything: seat walls; decorative interior or exterior finishes; sound walls that abut a freeway; retaining walls to hold back the earth; to the very walls that comprise the exterior of a home. Concrete has become the new flooring material of choice for designers and homeowners across the United States. Concrete floors are popping up in retail stores, trendy restaurants, offices, and homes everywhere. Whether it's acid-stained, painted, overlays, micro toppings, radiant floors, or a unique personal floor, concrete floors offer a range unlike any other material. Concrete flooring, sometimes referred to as cement flooring, no longer has to be gray and boring. Now coloring concrete or applying textures, patterns, saw cuts, etc., can bring new life to this traditional substrate.

One of the major benefits of concrete floors is their affordability compared to other flooring options. Installing a decorative concrete floor can be quite cost-effective, particularly if you already have a concrete slab that’s ready for staining, polishing or application of a coating or overlay. A basic concrete floor will carry a comparable price tag to linoleum, vinyl, ceramic tile or carpet. While a more complex concrete floor design will run you about the same or slightly less than marble, granite, slate, or high-end wood. Furthermore, the lifetime cost of a concrete floor is very low because they require little upkeep and last for years.

A second thing that attracts business and homeowners to concrete flooring is its ease of maintenance. When properly sealed, concrete floors can be cleaned with a quick pass of a dust mop. For an occasional deep clean a neutral cleaner and water can be used. The frequency of maintenance is dependent on the amount of traffic the floor receives. Restaurants and businesses with considerable foot traffic may want to use a sacrificial floor wax in addition to a sealer to further protect from abrasion.

Here are some additional benefits of concrete floors according to Barbara Sargent of Kemiko Concrete Floor Stains:

• They enhance the integrity of architect's designs.

• They are easy to change, especially if you sell your home; the next owner can place carpet or wood on top of the concrete slab.

• They are great in regions with a lot of sand or snow.

• They are a good alternative to carpet if you have allergies.

Fig 6.1 Concrete wall

6.2 Precast Cladding Panels

Precast concrete panels are reinforced concrete units available in a wide range of mixes, colours and finishes. Finishes can include acid-etched, smooth or coarse ground, grit or sand-blasted, rubbed or polished. Mixes designed to resemble natural stone can also be produced. Highly articulated designs can be accommodated by the mouldable concrete mix.

Benefits

• Faster programme times - not affected by weather or labour shortages.

• Improves buildability.

• Early enclosure of dry envelope enables follow-on trades to start sooner.

• Produces a high standard of workmanship in factory conditions - reduces potential for accidents, addresses on-site skill shortage.

• Has a high quality finish that can be left exposed - concrete's thermal properties can

• be exploited in low-energy buildings

Fig 6.2 ACP Cladding

6.3 Precast Flat Panel System

Floor and wall units are produced off-site in a factory and erected on-site to form robust structures, ideal for all repetitive cellular projects. Panels can include services, windows, doors and finishes. Building envelope panels with factory fitted insulation and decorative cladding can also be used as load-bearing elements. This offers factory quality and accuracy, together with speed of erection on-site

Fig 6.3 Panel system

6.4 Volumetric modules

3D Volumetric construction (also known as modular construction) involves the production of three-dimensional units in controlled factory conditions prior to transportation to site.

Modules can be brought to site in a variety of forms, ranging from a basic structure to one with all internal and external finishes and services installed, all ready for assembly. The casting of modules uses the benefits of factory conditions to create service-intensive units where a high degree of repetition and a need for rapid assembly on-site make its use highly desirable.

Fig 6.4 Volumetric Module

6.5 Twin Wall Technology

Twin wall technology is a walling system that combines the speed of erection and quality of precast concrete with the structural integrity of in-situ concrete to provide a hybrid solution. The prefabricated panels comprise two slabs separated and connected by cast-in lattice girders. The units are placed, temporarily propped, then joined by reinforcing and concreting the cavity on site. Twin wall is usually employed in association with precast flooring systems.

The panels are manufactured to exacting tolerances, have a high quality finish, and can incorporate cast-in cable ducts, electrical boxes and service ports. Installation rates are of up to 100m2 per hour. Twin wall has excellent inherent fire resistance and acoustic performance.

Fig 6.5 Twin Wall Technology

6.6 Flat Slabs

Flat slabs are highly versatile elements widely used in construction, providing minimum depth, fast construction and allowing flexible column grids. Because this is one of the most common forms of construction, all construct members and many other concrete frame contractors can undertake this work. Flat slabs are particularly appropriate for areas where tops of partitions need to be sealed to the slab soffit for acoustic or fire reasons. Flat slabs are considered to be faster and more economic than other forms of construction, as partition heads do not need to be cut around down stand beams or ribs.

Flat slabs can be designed with a good surface finish to the soffit, allowing exposed soffits to be used. This allows exploitation of the building’s thermal mass in the design of heating, ventilation and cooling requirements, increasing energy efficiency. Flat slabs provide the most flexible arrangements for services distribution as services do not have to divert around structural elements.

Fig 6.6 Flat Slab

6.7 Thin Joint Masonry

In masonry, mortar joints are the spaces between bricks, concrete blocks, or glass blocks that are filled with mortar or grout. Mortar joints can be made in a series of different fashions, but the most common ones are raked, grapevine, extruded, concave, V, struck, flush, weathered and beaded.

In order to produce a mortar joint, the mason must use one of several types of jointers (slickers), rakes, or beaders. These tools are run through the grout in between the building material before the grout is solid and create the desired outcome the mason seeks

Thin joint block work (thin joint masonry) is a fast, clean, accurate system for construction using autoclaved aerated concrete blocks of close dimensional tolerance with 2mm-3mm mortar joints. Thin layer mortar is a pre-mixed cement-based product that only requires the addition of water to make an easily-applied mortar. The benefits offered by thin layer mortars are provided by a system with many of the characteristics of traditional block work construction.

Fig 6.7 Thin Joint Masonry

6.8 Concrete Formwork

Formwork is a structure, usually temporary, used to contain poured concrete and to mould it to the required dimensions and support until it is able to support itself. It consists primarily of the face contact material and the bearers that directly support the face contact material. Formwork systems used for concrete frame construction have continued to develop significantly since the early 1990s. The major innovations have focused on on-site efficiency of production, health and safety, and environmental issues, driving the concrete construction industry towards ever-increasing efficiency. Different formwork systems provide a wide range of concrete construction solutions that can be chosen to suit the needs of a particular development.

Traditional formwork for concrete construction normally consisted of bespoke solutions requiring skilled craftsmen. This type of formwork often had poor safety features and gave slow rates of construction on-site and huge levels of waste.

The main types of formwork systems in use now are:

• Table form/flying form

• System column formwork

• Horizontal panel

• Slip form

• Tunnel form

The modern formwork systems listed above are mostly modular, which are designed for speed and efficiency. They are designed to provide increased accuracy and minimize waste in construction and most have enhanced health and safety features built-in.

Fig 6.8 Concrete Formwork

6.9 Precast Foundation

Precast concrete foundation and wall panels can take many forms. Some consist of steel-reinforced concrete ribs that run vertically and horizontally in the panels. Others are solid precast concrete panels. Panels are precast and cured in a controlled factory environment so weather delays can be avoided. A typical panelized foundation can be erected in four to five hours, without the need to place concrete on site for the foundation. The result is a foundation that can be installed in any climate zone in one sixth of the time needed for a formed concrete wall.

Some manufacturers cast the concrete against foam insulation that provides the form during manufacture and added R-value in the wall. Panels range in size from 2'-12' in width by 8' - 12' in height and are typically installed with a crane on top of 4" to 6" of compacted stone. The stone facilitates sub-slab drainage and adequately carries and transfers the load from the foundation wall. Panel connections consist of bolts and sealant. The foundation can be backfilled as soon as it is braced per manufacturer's specifications.

The controlled temperature of the processing plant allows the manufacturer to work with concrete admixtures that focus on ultimate strength rather than cure time and temperature. Manufacturers are able to produce mixes that harden to 5,000 psi, which is stronger than concrete block or concrete walls formed and cast in the field. Better control of the concrete mixture and curing environment allows the use of low water/cement ratios that results in a dense material that prevents water penetration.

Fig 6.9 Precast Foundation

CHAPTER 7

CONCLUSION

As can be seen through-out the above report, the use of a precast frame and a thin coat spray on plaster finish on this development can produce significant reductions on the overall construction programme while also not only maintaining, but excelling the standards set out in the original specification.

The precast frame exceeds specification as it will be 60N concrete and manufactured to a very high specification in a factory controlled environment. Tight factory production control ensures that the re-enforcement is located accurately and the panels are made to tight dimensional tolerances. Structural connections are also accurate which assists in the accurate installation of cladding, windows and other elements thereafter. Furthermore precast concrete improves structural efficiency as longer spans and shallower construction depths can be obtained using prestressed floors and/or beams. Most importantly, there will be no additional work created for the design team as the precast manufacturer produces their own in-house precast drawings for approval by the architect thus design costs do not change or increase.

The limitations of the topic “Modern Construction Technology” is very enormous and massive. Therefore, it not possible to covers all the topic and chapters in this report. Therefore , this report has limited topics related to “Modern Construction Technology” which are as follows:-

1. Concrete Walls and Floors.

2. Precast Cladding Panels.

3. Precast Flat Panel System.

4. Volumetric Modules.

5. Twin Wall Technology.

6. Flat slabs.

7. Thin Joint Masonry.

8. Concrete Formwork.

9. Precast Foundation.

The benefits of modern methods of construction are too positive to be ignored.. Modern methods of construction can provide large numbers of sustainable, well-designed homes in a short period of time. Modern methods of construction also afford an opportunity to overcome the skills shortage in the construction industry through factory production.. Modern methods of construction will be a key tool in addressing this challenge and should be viewed as an opportunity for the house building sector to increase capacity and choice in the housing market.Modern construction technology have evolved from the more conventional methods to a large extent. Modern construction technology is those that provide greater efficiency in the construction process, resulting in increased production, better quality, in less time and with less waste, so reducing the environmental impact. Modern construction technology is a process to produce more, better quality homes in less time.

REFERENCES

1. Modern methods of constructions and their components (Lenka Kyjaková , Tomáš Mandičák & Peter Mesároš)

2. Modern methods of construction: a solution for an industry characterized by uncertainty (Ylva Sardén1 And Susanne Engström)

3. Study on modern methods of constructions used in Srilanka H.M.M.Uthpala1, T.Ramachandra.

4. Modern methods for cost management in construction enterprises Peter Mesároš, Tomáš Mandičák, Jozef Selín

5. Acceptance theories of innovation and modern methods in construction industry Daniela Ma˘Ckov´ A, Tom´A˘S Mandi˘C´Ak

6. www.google.com

7. www.wikipedia.com

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CONCRETE CLOTH (Page 2)

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CHAPTER-2

HISTORY OF CONCRETE CLOTH

The British Engineering Company had found the revolutionary material, concrete cloth. It’s a recent innovation in the concrete sector.The technology was first found for emergency shelters, application to military world and later on applied to commercial construction work.

2.1 CONCRETE CLOTH AS REINFORCING SANDBAGS

The British Army used the method of reinforcing sand bag for defence; this reduces the degradation of sandbags (figure given below) in extreme climates of Afghanistan, where the combination of wind, sand and extreme temperature affects the sandbags for a frequent repair. Moreover it was fireproof.

They are made compact to work even in remote areas by manufacturing them in a compact size (10 m or 33 ft), made them easy to handle without any of the heavy lifting equipment’s or planting machinery’s. That forms a biggest advantage when work in remote area where the helicopter is the only way to mode of transport.

The fibers used in them forms a reinforcing matrix within the concrete cloth. Thus when impacted this property of fibers used helps to serve the structural integrity of concrete. A ballistic attack may pass through them, but crack propagation is limited, as a result, the sandbags remain safe inside the concrete shell.

In January 2008, a notable amount of concrete cloths are laid in the frontline in Afghanistan to analyze the field usage and the performance which is satisfactory for the U.K army.

Fig.2.1.1 CC as reinforcing sandbags

(Source: www.concretecanvas.co.uk)

2.2 CONCRETE CLOTH AS DEPLOYABLE SHELTER

The research of concrete clothes is to develop rapid hardening shelters only using the water and air. Concrete Canvas Shelters have two major advantages over conventional tented shelter:

1. Operational: It enables a hardened structure from day one of an operation. They provide much better environmental protection, increased security and vastly improved medical capability.

2. Financial: They have a design life of over 10 years, whereas tents wear out rapidly and must then be replaced. They are a one stop solution, saving effort and cost over the lifetime of medium to long term operations.

The key was the use of inflation to create a surface that was optimized for compressive loading. This allowed thin-walled concrete structures to be formed that are both robust and lightweight.

The University ofBath in Bath, UK, has conducted finite element analysis of the shelters, showing that the structures can withstand a high distributed compressive load.

2.2.1 PACKAGING

Concrete Canvas Shelters (CCS) are supplied in polyethylene, airtight, water proof, rot proof sacks within ISPM15 heat treated timber/ply panel crates.

CCS are rapidly deployable structures that can be deployed by two people in less than 24 hours. There are two shelter sizes available, the CCS25 and the CCS50 with respective deployed areas of 25 and 50sqm.A CCS50 will require a vehicle or winch to aid with the unfolding of the shelter prior to inflation. Each shelter is provided with the ground pegs required for inflation. CCS are prefabricated structures consisting of Concrete Canvas fixed to an inflatable inner with integral steel door sets at each end. The shelter is deployed in the following four stages:

2.2.1 a. Delivery

The shelter is supplied folded and sealed in a sack. The 16 m2 variant is light enough to transport in a pickup truck or light aircraft.

2.2.1 b. Inflation

Once delivered, an electric fan is activated to inflate the inner PVC liner and lift the structure until it is self-supporting.

2.2.1 c. Hydration

The shelter is sprayed with water. Hydration is aided by the fiber matrix, which wicks water into the mixture

2.2.1 d. Setting

The Concrete Cloth cures inthe shape of the inflated inner PVC liner. The structure is ready to use 24 hours later.

Access holes allow the installation of services such as water, power, air conditioning, and heating units. The shelters have excellent thermal properties and protection against blasts, and small arms fire. A shelter using CC is shown in figure.

Fig. 2.2.1 CC as deployable shelter

(Source: www.concretecanvas.co.uk)

CHAPTER-3

MATERIAL PROPERTY

3.1 STRENGTH

Very high early strength is a fundamental characteristic of concrete cloth. The first crack strength of CC is attributed to two aspects: matrix strength and fiber bridging effect. The first crack strength σfc is defined as the applied tensile stress at which a matrix crack spreads throughout the cross section of the sample under tension. The maximum bridging stress σB is defined as the maximum stress that bridging fibers can transfer across the crack of specimen.

Typical strengths and physical characteristics are as follows:

Compressive testing

The test is based on ASTM C473-07.By the test the 7 day minimum compressive strength is equal to 38 MPa

Bending test:

This tests based on ASTM C-1185. The test is used to determine the ability of material to resist the bending. The 7 day minimum bending stress is equal to 3.3 MPa and 7 day modulus minimum is equal to 180 MPa.

Abrasion Resistance:

ASTM C1353-8 is the standard test method to determine abrasion resistance of the material. CC lost 60% less weight than marble over 1000 cycles.

Resistance to imposed loads on vehicle traffic areas:

EN 1991-1-1:2002 is the standard testing method (for CC8&CC13 only). The gross weight of two axle vehicle should be between 30 to 160 kN and the uniformly distributed load should not exceed 5kN/sq.m

CBR puncture resistance:

Test is based on EN ISO 12236:2007. The test is used for CC8& CC13. The minimum push-through force is equal to 2.69 kN and the maximum deflection at peak is 38 mm.

3.2 PHYSICAL PROPERTIES

Setting time

The time between the end of mixing and initial set of a material made with a hydraulic binder or the hydraulic binder itself. The initial setting time should be greater than or equal to 120 minutes and the final setting time is greater than or equal to 240 minutes. Concrete canvas will achieve 70-80% strength in 24 hours after hydration.

Density

The dry density of Concrete Cloth before hydration is 1500 kg/cc Upon Complete hydration the density increases 30-35% to a range of about 1950-2025 kg/cc.

Thickness

Concrete Canvas is available in 3-thicknesses; CC5, CC8 & CC13, which are 5, 8 & 13 mm thick respectively. There is theoretically no limit to the thickness of the fabric, although it will generally be limited by the manufacturing techniques used to produce it. A typical thickness would be between 2 and 15mm. One important consideration limiting the thickness of the material is the ability of the liquid to penetrate through the interior of the settable material before the outer portions of the settable material is set. A further limitation on the thickness comes from the increased Weight of the fabric with increased thickness and if it is too thick, the faces may not be able to support the Weight of the settable material within the fabric.

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CONCRETE CLOTH (Page 3)

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CHAPTER-4

METHOD OF HYDRATION& WORKING

Concrete cloth can be hydrated using saline or non-saline water. The minimum ratio of water to Concrete Cloth is 1:2 by weight. It cannot be over hydrated so an excess is recommended. The recommended methods are: In a hot/arid environment, re-wet the material 2 - 4 hours after the initial hydration.

Immersion:

Immerse Concrete cloth in water for a minimum of 90 seconds.

Spraying:

Spray the dry Concrete cloth with water until it is saturated. Do not use a direct jet of pressurized water as this may wash a channel in the material and create a weakened area.

WORKING

It is bifurcated into four steps

4.1. Unpacking

At the time of installation, CC comes in two forms, Bulk roles or Batched roles (shown in figure)which are flexible in nature.CC is available in two standard roll sizes; bulk rolls or smaller batched, portable rolls the quantity per roll differs between the CC types. Bulk rolls weigh about 1.7 Tons (~3400 lbs.) and are supplied on 6 inch cardboard tubes which can be hung from a spreader beam and unrolled using suitable equipment (see picture below). Bulk rolls provide the fastest method of laying CC and have the additional advantage of reducing the number of joints required.

Batched rolls are supplied on 3 inch inner diameter cardboard cores with carry handles, and can be easily handled by 2 to 4 people. All CC thicknesses can be supplied batched to custom lengths for an additional charge. Bulk rolls are individually wrapped and palletized. All CC rolls are provided with a basic hydration guide placed within the packaging.CC batched rolls are individually wrapped in airtight packaging and palletized. 10 batched rolls fit on a standard 4 x 4 pallet. CC13 is not supplied in a standard batch roll size.

FIG.4.1.1 Batch rolls

(Source: www.concrete canvas.co.uk)

FIG.4.1.2 Bulk rolls

(Source: www.concrete canvas.co.uk)

4.2. Storages

CC should be stored in dry conditions away from direct sunlight and in the manufacturers sealed packaging. If stored correctly CC has a shelf life of 24 months. If stored for longer CC may remain usable in many instances.

4.3. Cutting and Fastening

The cloth is laid on the point of application, cut into proper size and shape, and fastened to the place using staples, Nails and screws.CC A snap off type disposable blade is the most suitable tool for cutting CC before it is hydrated or set. When cutting dry CC, a 3/4 allowance should be left from the cut edge due to lost fill. This can be reduced by wetting the CC prior to cutting. Set CC can be cut as with conventional concrete, with angle grinders, construction disc cutters or tile cutters. CC can also be cut using handheld self-sharpening powered disc cutters. CC sheets in all three thicknesses can also be water cut to a fine resolution. There are a large number of mechanical fasteners that are suitable for use with Concrete Cloth. Some of these fasteners can be used in conjunction with the non-mechanical joining methods described later in this guide to improve the mechanical strength or water proofing properties of joints.

The versatility of CC means that a wide range of manual, electric or gas powered staplers are suitable for attaching CC to soft substrates such as wooden boarding for building cladding. Commercially available hand staplers are suitable for fixing 2 layers of CC together where a small amount of compression force is required - such as with the simple overlap joint described in the CCNon- Mechanical Fastening Techniques section of this brochure. Standard nails can be used to attach CC. Alternatively, a power tool such as the Hilti nail gun, provides a quick and effective method of securing CC to hard surfaces such as concrete or rock. This may be appropriate where CC is being used to recondition an existing concrete surface or for spall lining in mining applications. It is important to ensure that the nail is used with at least a 1/2 washer to ensure the head does not penetrate through the surface of the Cloth. CC fastening using standard nails and electric stapler can be seen in figure given below.

FIG. 4.3.1 CC Fastening using standard nails

(Source: www.concrete canvas.co.uk)

FIG. 4.3.2 CC Fastening using electric stapler

(Source: www.concrete canvas.co.uk)

4.4. Hydrating

After fastening of CC to desired place, it only needs to be hydrated for its final hardening. It is designed in such a way that, it cannot be over hydrated. Only in 24 hours Concrete cloth is ready to serve its purpose.

CHAPTER-5

MARKET AVAILABILITY

Concrete cloth is available in two standard roll sizes; bulk rolls or smaller batched rolls. Bulk rolls provide the fastest method of laying Concrete cloth and have the additional advantage of reducing the number of joints required.

The shelter is supplied folded and sealed in a sack. The 16 m2 variant is light enough to transport in a pickup truck or light aircraft.

There are 3 Concrete cloth types available with the following indicative specifications

5.1. ROAD

Concrete Canvas (CC) provides a durable water management and erosion control solution for new and existing road infrastructure projects. Some specific examples of applications are:

Ditch Lining

Slope Protection

Outfall Protection

CC has quickly gained market acceptance in the civil engineering sector as a cost effective alternative to conventional concrete in ditch lining and slope protection applications.

The speed of installation minimizes traffic disruption and reduces the risks associated with roadside work. CC ditches prevent weed growth and erosion, reducing the maintenance costs associated with unlined ditches, but will naturally ‘green’ over time, helping it blend into the environment.

Existing users of CC in the Rail sector include:

UK Highways Agency

Enterprise Mouchel, UK

Skanska Balfour, UK

Costain, UK

5.2. RAIL

Concrete Canvas (CC) has been used in the rail sector since 2009 and is rapidly establishing itself as the construction material of choice with network providers around the world. Some specific examples of applications are:

Ditch Lining

Slope Protection

The speed and ease of installation means that CC is well suited to time-critical track-side work, vastly reducing line possessions and overall project costs. Eliminating issues associated with rebound from shotcrete means slope protection work can continue without line closures.

The resulting reduction in staffing levels and plant requirement has obvious safety benefits for contractors.

Existing users of CC in the Rail sector include:

UK Network Rail

Canada National Rail

ADIF, Spain

5.3. UTILITIES

Concrete Canvas (CC) is increasingly being used by utilities such as power, waterworks, landfill and hydro-electric companies. Some specific examples of applications are:

Ditch Lining

Slope Protection

Pipe Protection

Cable Covering

CC is increasingly being used as slope protection on sites with sensitive infrastructure such as power stations.

Unlike shotcrete, CC produces no back spray, debris or rebound, eliminating the need for site closures or costly clean-up operations post-installation. Concrete Canvas (CC) can also be used as practical, simple to install coating for pipeline or cable protection.

Existing users of CC in the Utility sector include:

Iberdrola, Qatar

Duncan Mackay & Sons, UK

COMSA EMTE, Spain

Stornaway Council, UK

5.4. MUNICIPAL

Concrete Canvas (CC) has been used on a large range of projects for national governments, public works, councils and local authorities. Some specific examples of applications are:

Gabion Reinforcement

Ditch Lining

Slope Protection

CC has an expected design life of over 50 years and has more than 200 cycles of freeze-thaw testing.

The concrete used within CC is extremely hard wearing and has twice the wear resistance of OPC; as well as excellent resistance to chemical attack and UV degradation.

Existing users of CC in the Municipal sector include:

Caerphilly Council, UK

Ras Al Kaimiah, UAE

Far North Council, New Zealand

Rother Council, UK

5.5. MINING

Concrete Canvas (CC) is being used extensively on large-scale mining projects around the world with customers in South Africa, Canada, Chile, Australia and the UK. Some specific examples of applications are:

Ditch Lining

Vent Walls

Slope Protection

CC cannot be over-hydrated and there is no need for mixing, measuring or compacting on site.CC is well suited to use in extreme environments and has been used installed in environments with sub-zero temperatures such as Northern BC in Canada and at 4000m altitude in the Chilean Andes.

Existing users of CC in the Mining sector include:

Vale, Canada

Barrick, Chile

British Gypsum, UK

Coal Authority, UK

5.6. AGRO

Concrete Canvas (CC) is well suited to agricultural applications where water management and erosion control are key. Some specific examples of applications are:

Remediation

Ditch Lining

Slope Protection

CC also has a low alkaline reserve, a low washout rate and a low carbon footprint, ensuring minimal impact on the environment.

CC can be used to reline existing concrete infrastructure in fisheries, canals or irrigation ditches, allowing time-critical remediation work to be completed quickly and easily.

Mendez Soluciones, Chile

ConcesiónSabana De Occidente, Colombia

OranjeRiet Water Users Association, South Africa

OSEPA Confed. Hidrografica del Ebro, Spain

5.7. PETROCHEMICAL

Concrete Canvas (CC) is increasingly being used by oil and gas companies around the world for a wide range of containment, erosion control and water management applications. Some specific examples of applications are:

Bund Lining

Pipe Protection

Ditch Lining

CC is typically 10 times faster to install than conventional concrete solutions, reducing plant and personnel on site and consequently improving site safety.

CC can also be supplied in batched rolls allowing work to be done in areas with limited access.

Existing users of CC in the Petrochem sector include:

Phillips 66, UK

Petrobras, Brazil

Pacific Rubiales, Colombia

Shell, UK

5.8. DESIGN

Concrete Canvas (CC) has been used by a huge variety of designers, architects and artists. From furniture to conceptual fitness apparatus, sculptures to art installations, CC’s flexibility, durability, ease of use and fabric-like aesthetic has led to it being used in projects worldwide. Some specific examples of applications are:

Furniture

Artistic

Exhibition

Pre-hydrated CC can be cut using hand tools, and the material can be fixed to itself or other surfaces in many different ways.

Set CC can be cut and drilled as with conventional concrete, using angle grinders, construction disc cutters or high-quality tile cutters. It can also be water cut to a fine resolution. CC has excellent drape characteristics, allowing the material to conform to complex shapes, and the fiber surface of CC can be easily painted once set using standard exterior masonry paint.

Existing users of CC in the Design sector include:

Wolfson Design

David Booth

Florian Schmid

Swedish Ninja

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CONCRETE CLOTH (Page 4)

2017-01-11T10:12:00.000-08:00

CHAPTER-6

APPLICATIONS OF CONCRETE CLOTH

6.1. DITCH LINING

Fig 6.1 Ditch lining

(Source: www.concrete canvas.co.uk)

Concrete cloth can be rapidly unrolled to form ditch or tank lining. It is significantly quicker and less expensive to install than conventional concrete ditch lining and requires no specialist plant equipment. Traditionally, the most common renovations were toreplace smaller canals with pipelines and line larger canals with concrete. But lining canals with concrete is expensive and requires significant upkeep.

Concrete Cloth is typically 10 times faster to install than conventional concrete solutions, with installation speeds of up to 200sqm/hr.

Less time required on site, less vehicle movements, manual handling issues associated with slab lining are eliminated.CC5 and CC8 are available in 60kg and 70kg man-portable batched rolls.

Concrete Canvas (CC) can be used to rapidly reline existing concrete structures suffering from environmental degradation and cracking.

CC provides a remediation solution which is fast, easy and cost effective to install.

Cost Saving: Repairing existing concrete infrastructure can prove costly, difficult and time-consuming, typically requiring the removal and replacement of existing concrete which is extremely difficult, requires heavy plant and a large site team.

Improved Impermeability: CC joints can be thermally welded or sealed with mortar to effectively reduce water loss.

Minimum Volume Loss: CC typically replaces 100-150mm of poured or sprayed concrete. Therefore re-lining a channel or reservoir with just 5, 8 or 13mm of CC minimizes capacity losses associated with conventional solutions.

6.2. SLOPE PROTECTION

FIG.6.2 Slope protection

(Source: www.concrete canvas.co.uk)

Landslides may occur due to shallow erosion orreduction of shear strength caused by seasonal rainfall, and may be triggered by anthropic activities such as adding excessive weight above the slope, digging at mid-slope or at the foot of the slope.

Concrete cloth can be used for slope stabilization and other erosion control applications such as temporary and permanent slope protection, retaining walls, boulder fences, low level bunds and river bank and dam revetments.

6.3. PIPELINE PROTECTION

Concrete cloth can be used as a coating for overland or underwater pipeline protection, providing a superior tough rock shield. In remote areas it can be used to coat steel pipe on site without expensive wet concrete application plants. It will set underwater and provide negative-buoyancy.

Fig. 6.3 Pipeline protection

(Source: www.concrete canvas.co.uk)

6.4. OUTFALL PROTECTION

Concrete Canvas (CC) has been used worldwide as an effective method of preventing surface erosion and scour associated with water run-off from culverts outlets, spillways and over-toppings.

CC provides an outfall protection solution which is fast, easy and cost effective to install.CC can be installed by personnel with minimal training. The material can be cut and fixed with basic hand-tools. CC cannot be over-hydrated and there is no need for mixing, measuring or compacting on site.

CC has double the wear resistance of standard OPC and has passed over 200 cycles of freeze-thaw testing giving it a minimum design life of 50 years in a UK climate.

Fig 6.4 Outfall protection

(Source: www.concrete canvas.co.uk)

6.5. GROUND RESURFACING

Concrete cloth can be secured with ground anchors to rapidly create a concrete surface for flooring, pedestrian walkways or dust suppression.

Repairing existing concrete infrastructure can prove costly, difficult and time-consuming, typically requiring the removal and replacement of existing concrete which is extremely difficult, requires heavy plant and a large site team.

Fig. 6.5 Resurfacing

(Source: www.concrete canvas.co.uk)

6.6. MINING APPLICATIONS

Concrete cloth can be used as an alternative to poured or sprayed concrete or as a quick way of erecting strong permanent or temporary blast and vent structures and spall lining.

Trials have shown that CC typically provides cost savings of over 20% compared to conventional solutions.

Fig.6.6 Mining

(Source: www.concrete canvas.co.uk)

6.7. BUND LINING

Earth containment bunds can be quickly lined with concrete cloth to provide an efficient, chemically resistant alternative to concrete walling. Bund lining also called a bund wall, is a constructed retaining wall designed to prevent inundation or breaches from a known source. It is a secondary containment system commonly used to protect environments from spills where chemicals are stored. CC can be used for hard armour capping of earth bunds around petrochemical tank farms, munitions depots and flood defences. CC acts as an effective weed inhibitor, eliminating the maintenance required with grassed or earth bunds whilst providing a safe surface for trafficking.

6.8. GABION REINFORCEMENT/CAPPING

Fig.6.7 Capping

(Source: www.concrete canvas.co.uk)

Gabion is a cage, cylinder, or box filled with rocks, concrete, or sometimes sand and soil for use in civil engineering, road building, and military applications.In a military context, earth- or sand-filled gabions are used to protect artillery crews from enemy fire.

Concrete cloth can be used to cap or repair gabion walls to provide long-term protection and prevent FOD (Foreign Object Damage). CC helps prevent loss of fill if the geo-textile has degraded from UV exposure or weathering and securely ties together multi-level gabion walls preventing movement and extending their life by decades.

CC provides a gabion covering solution which is fast, easy and cost effective to install. Capping: CC prevents water ingress which can cause slump due to water saturation and the migration of fines.

6.9. DUST SUPPRESSION SYSTEM IN HELIPAD

Fig.6.8 Helipad

(Source: www.concrete canvas.co.uk)

The turbulent air currents created by the helicopter rotor wash drives loose soil particles into the air.

The airborne dust particles negatively impact humans and wildlife, including aquatic life and vegetation. The dust also increases vehicle, helicopter, and equipment wear and damage due to mechanical abrasion.

So the concrete cloth was used as a dust suppression surface around Helicopter Landing Sites.

CHAPTER-7

CASE STUDY

SHERSTON RAIL DITCH

In June 2014, Concrete Canvas was used to line a drainage ditch located at the top of a railway embankment in Sherston, Wiltshire, UK. The works took place as part of the Great Western Electrification Programme (GWEP), which involves raising and replacing various bridges, upgrading tunnels and carrying out safety improvement work to parapets between London and Cardiff. In this instance, local rail bridges were being elevated which resulted in the need to remove a nearby aqueduct that couldn’t be re-positioned. The drainage channel was designed to replace this loss of water management capacity and to prevent slip of the embankment through surface erosion and saturation.

Site access was limited due to the close proximity of the rail line and plant was only accessible via rented farm space, so speed of install was paramount. Concrete Canvas® GCCM was specified due to its ease of and speed of install, which significantly reduced time on site and cost of access. With a fall of only 2mm, an unlined V ditch was deemed unsafe as ground and surface water would not drain correctly and cause risk of slip. Either an unlined ditch or a pipe work option would require regular and expensive maintenance, placing CC8 as the most cost-effective solution. Installation was carried out by BAM Nuttall with consultancy provided by Network rail in conjunction with ADAS (the Agricultural Development Advisory Service).

Loose rock was removed from the invert so that there was intimate contact between the CC8 and the base of the ditch. Bulk rolls of CC8 were called off in staggered deliveries to site providing logistical flexibility in line with the rate of install. The bulk rolls were deployed from spreader beam equipment to maximize speed of install. The material was unrolled into the ditch transversely and cut to specific profile length.

Fig.7.1 Sherston rail ditch before lining

(Source: www.concrete canvas.co.uk)

Fig.7.2 Sherston rail ditch after lining

(Source: www.concrete canvas.co.uk)

CHAPTER-8

ADVANTAGES OF CONCRETE CLOTH

RAPID CONSTRUCTION

A 25sqm CCS can be deployed by 2 people in less than 1 hour and is ready to use in only 24 hours. The material can be hydrated by either spraying it or fully immersing it in water. Once hydrated, it remains workable for 2 hours and hardens to 80% of its final strength within 24 hours.

EASY TO USE

Dry concrete cloth can be cut or tailored using simple hand tools such as utility knives. The PVC side can be supplied with an adhesive backing and the fibrous side bonds well to concrete or brick surfaces when set. It can be easily repaired or upgraded using existing cement products.

FLEXIBLE

Concrete cloth can be easily nailed through before setting. It has good drape characteristics, allowing it to take the shape of complex surfaces including those with double curvature.

STRONG

The fiber reinforcement acts to prevent cracking, absorbs energy from impacts, and provides a stable failure mode.

FIREPROOF

Concrete cloth is a ceramic-based material and will not burn.

WATERPROOF

The PVC backing on one surface ensures that concrete cloth is completely waterproof.

ADAPTABLE

Concrete cloth is currently supplied on 1.2 m wide rolls but can be manufactured with a roll width of up to 5 m. The cloth can be produced in a range of thicknesses from 5 to 20 mm.

DURABLE

Concrete cloth is chemically resistant and will not degrade in ultraviolet light. They are far more durable than conventional soft skinned tents with a design life of over 10 years.

ENVIRONMENT FRIENDLY

The material can be reused and recycled.

EARTH BERMING

The compressive structure of CCS has been modeled to be covered with sand or earth fill, to provide additional thermal mass and insulation providing excellent level of thermal performance.

CHAPTER-9

LIMITATIONS OF CONCRETE CLOTH

Concrete cloth cannot be over hydrated and an excess of water is always recommended.

Jets of high pressure water should not be impacted directly onto the concrete cloth as this may wash a channel in the material.

Concrete cloth has a working time of 1-2 hours after hydration. So CC cannot be moved once it has begun to set.

Working time will be reduced in hot climates.

If concrete cloth is not fully saturated, the set may be delayed and strength may get reduced.

CHAPTER-10

CONCLUSION

Concrete Cloth (CC) is a unique proprietary material. It is a time & material saving technique. It is very easy to place & handle. Concrete cloth is a thin, flexible, durable, water & fire proof concrete layer. CC allows concrete construction without the need for plant or mixing equipment. Concrete canvas reinforced by 3D spacer fabric with one solid outer textile substrate exhibited improved tensile behaviours.CC has a design life of 10 years and is significantly quicker and less expensive to install compared to conventional concrete. It is specially used, where the workmanship is very difficult and is mainly used in emergency works such as in military.

REFERENCES

1. V. Vedha Narayanan, International Journal on Applications in Civil and Environmental Engineering Volume 1: Issue 3: March 2015, pp 6-12. www.aetsjournal.com

2. Hrishikesh R. kane, Pratik D. Akarte, Roshan B. Akhude, P.S Randive. International Journal for Engineering Applications and Technology Volume 1, pp 2-7.

http://www.ijfeat.org/

3. Maqbool Akhtar, Rajendra Singh Dangi. International Journal for Scientific Research and Development Volume 3: Issue 01: 2015, pp 314-315.

www.ijsrd.com

4. F. Han et al. 3D spacer fabrics. Construction and Building Materials 65 (2014) 620–629

5. http://www.concretecanvas.com/

6. http://www.concreteinternational.com/

7. Armakan DM, Roye A. A study on the compression behavior of spacer fabrics designed for concrete applications. Fiber Polym 2009; 10(1):116–23.

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CONCRETE CLOTH

2017-01-11T10:07:00.000-08:00

By Shibi

Page 1

CHAPTER-1

INTRODUCTION

Concrete cloth is an upcoming revolution in civil world, which in turn have a wide range of application in rapid construction, in state of emergency etc. due to its own physical property, mainly, flexibility and easy to use. Among various engineering applications of 3D spacer fabric reinforced cementitious composites; concrete canvas (CC, the concept was first proposed by Brewin and Crawford in 2005) is one of the most promising products.

Concrete cloth is a flexible concrete impregnated fabric that hardens on hydration to form a thin, durable, water and fire proof layer. Like soft cloth,CC can closely cover the surface of arbitrary structure or element before using. Its shape is completely the same as the outer profile of the structure or element where CC is covered. Essentially, it’s concrete on a roll.CC allows concrete construction without the need for plant or mixing equipment. Simply position the canvas and just add water. The water does not need to be potable, and bore-hole water, river water or seawater can be used. No major ground excavation or foundation work is required.

Concrete cloth consists of a 3- dimensional fiber matrix containing a specially formulated dry concrete mix. A PVC backing is provided on one surface to make it water proof. The other side of the cloth is aided with a hydrophilic fiber (polyethylene and polypropylene yarns) and thus hydration occurs by drawing water into the mixture.

The cloth may be hydrated either by spraying or by being fully immersed in water. To check whether water penetrated through the whole thickness of the sample, it was cut along the cross section after hardened. It was seen that the density of the paste in bottom layer was similar to the top layer. Therefore, the current water-spaying method guarantees that the water penetrated through the whole thickness of sample. The time-dependent compressive strength of cubic CSA-based CC sample with dimensions of 15 mm x 15 mm x 15 mm was also determined to obtain the suitable curing age for tensile test and 10-day compressive strength of the sample almost reached the maximum mechanical strength value. The geometric patterns of outer textile substrates of 3D spacer fabric play a vital role in loading capacity and the solid fabric dominate the tensile strength and ultimate elongation.

They can be easily nailed, stapled or coated with an adhesive for easy attachment to other surface. Once set, the fibers reinforce the concrete, preventing crack propagation & providing a safe plastic failure mode. Compared to traditional concrete solutions, it is faster, easier and more cost effective to install and has the additional benefit of reducing the environmental impact of concreting works by up to 95%.

Typical installation speeds are up to 10 times faster than conventional concrete solutions. It is available in man portable rolls eliminating the need for plant on site and allowing concrete installation in areas with limited access.

Prior to hydration, Concrete cloth layers can be cut to length using basic hand tools eliminating the hazards associated with using power tools in high risk environments. The concrete is pre-mixed so there is no need for mixing, measuring or compacting but just add water. It greatly reduces transportation cost and on site storage. It is a low mass, low carbon technology.

Fig 1.1 CC cross section

(Source: www.concrete canvas.co.uk)

PAGE

POWER GENERATION FROM FOOTSTEPS (Page 4)

2017-01-11T10:06:00.000-08:00

Page 4

CHAPTER 5

CONCLUSION

In order to overcome the energy crises problem and also contribute to create a healthy global environmental change, this technique need to be widely implemented. Thus this is a promising technology to provide efficient solution to power crisis to affordable extent. This will be the most acceptable means of providing power to the places that involves difficulties of transmission. Moreover walking across power producing platform will be a fun for idle people who can improve their health byexercising in such platforms with earning. The electrical energy generated at such farms will be useful for nearby applications. This technology would facilitate the future creation of new urban landscapes, athletic fields with a spectator area, music halls, theaters, nightclubs and a large gathering space for rallies, demonstrationsand celebrations, railway stations, bus stands, subways, airports etc. like capable of harnessing human locomotion for electricity generation. Though being advantageous in several aspects, such as manufacturing, installation, aesthetics, maintenance, availability etc, this technology can only contribute to low power applications. It requires highly-efficient converter mechanism and storage devices and has a less storage lifespan. Besides, the materials used in manufacturing the devices must be highly durable, as they will be operating throughout the year. As of today, this technology is in its nascent stages due to the above stated reasons. Development in the areas of storage and transmission of energy may eliminate all the drawbacks and make this an effective technology for power harvesting.

This type of technology may be well suited to other applications though. One potential application would be to connect one of these tiles directly to a low consumptions device. A few examples of such devices are a vending machine or a parking pass dispenser. A customer would walk or drive up the machine and depress the pad. This may be able to generate enough power to run the device for the very short period of time that it is in use. It would take very little power for a vending machine to push a candy bar forward or a machine to push out a parking pass.Another potential use of pavegen tiles would be education and awareness. Being "carbon neutral" or "energy neutral" is very much in style these days. These tiles could be implemented temporarily for major sporting events, festivals, concerts or similar things. The goal here would not be to save money. Instead, the event could advertise that it is not using any electricity from the grid. These days, that is a rather cool thing for an event to brag about. This could be a very effective way to create dialog and awareness of related energy issues.

REFERENCES

[1] C. M. Kacher, I. M. Weiss, R. J. Stewart, C. F. Schmidt, P. K. Hansma, M. Radmacher, and M. Fritz, European Biophysics Journal 28,pp 611, 2000.

[2] Marc A. Rose, “Engineering Health and Safety Module and Case Studies”, vol. 1, pp. 1-9, July 2004.

[3] Marcel Simard, Alain Marchand, “A multilevel analysis of organisational factors related to the taking of safety initiatives by work groups” vol. 1, pp. 5-9, 1995.

[4] Mr. A. Adhithan, K. Vignesh, M. Manikandan, Proposed Method of Foot Step Power Generation Using Piezo Electric Sensor,International Advanced Research Journal in Science, Engineering and Technology Vol. 2, Issue 4, April 2015,

[5] Paivi Hamalainen, JukkaTakala, Kaija Leena Saarela, “Global estimates of occupational accidents”, vol. 1,pp. 2-3, 2005.

[6] S. Brown, Proceedings of the National Academy of Sciences 89, pp 8651 1992.

[7]Shiraz Afzal, Farrukhhafeez“Power Generation from Footstep”

International Journal of Advancements in Research & Technology, Volume 3, Issue 4, April-2014 ,

[8]Sibabrata Mohanty, Sasankshekhar Panda“An Investigation on Generation of Electricity Using Foot Step”INTERNATIONAL JOURNAL OF ENGINEERING SCIENCES & RESEARCH TECHNOLOGY(IJESRT),May, 2014

[9] S. Whaley, D. English, E. Hu, P. Barbara, and A. Belcher, “Nature”, pp 665, 2000.

[10] Tom Jose V, BinoyBoban, Sijo M T, “Electricity Generation from foot steps; A generative Energy Resources” International Journal of Scientific and research publication, pp 1-3, March 2013

[11]www.patentonline.com

[12]www.Pavegen.com

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POWER GENERATION FROM FOOTSTEPS (Page 3)

2017-01-11T10:05:00.000-08:00

Page 1

CHAPTER 3

METHODOLOGY

The piezoelectric effect is understood as the linear electro-mechanical interaction between the mechanical and the electrical state in crystalline materials with no inversion symmetry. The piezoelectric effect is a reversible process in that materials exhibiting the direct piezoelectric effect (the internal generation of electrical charge resulting from an applied mechanical force) also exhibit the reverse piezoelectric effect (the internal generation of a mechanical strain resulting from an applied electrical field).

Fig.3.1 Piezoelectric principle

Source: www.ijsrp.org

Fig.3.2. Working principle

Source: www.irjset.com

3.1 Methodology

The nature of the piezoelectric effect is closely related to the occurrence of electric dipole moments in solids. The latter may either be induced for ions on crystal lattice sites with asymmetric charge surroundings or may directly be carried by molecular groups. The dipole density or polarization (dimensionality [cm/m3]) may easily be calculated for crystals by summing up the dipole moments per volume of the crystallographic unit cell. As every dipole is a vector, the dipole density P is a vector field. Dipoles near each other tend to be aligned in regions called Weiss domains. The domains are usually randomly oriented, but can be aligned using the process of poling (not the same as magnetic poling), a process by which a strong electric field is applied across the material, usually at elevated temperatures.

One of the decisive importance for the piezoelectric effect is the change of polarization P when applying a mechanical stress. This might either be caused by a reconfiguration of the dipole-inducing surrounding or by re-orientation of molecular dipole moments under the influence of the external stress.

Fig.3.3. Mechanism of kinetic footfall

Source:www.un-spider.org

3.1.1 Mechanical Stress

Here the mechanical stress is considered as the weight of the footsteps per unit area. The weight of the footsteps due to gravity is converted into mechanical rotation. stress is a physical quantity that expresses the internal forces that neighboring particles of a continuous material exert on each other. For example, when a solid vertical bar is supporting a weight, each particle in the bar pulls on the particles immediately above and below it. When a liquid is under pressure, each particle gets pushed inwards byall the surrounding particles, and, in reaction, pushes them outwards. These macroscopic forces are actually the average of a very large number of intermolecular forces and collisions between the molecules in those particles. Stress inside a body may arise by various mechanisms, such as reaction to external forces applied to the bulk material (like gravity) or to its surface (like contact forces, external pressure, or friction). Any strain (deformation) of a solid material generates an internal elastic stress, analogous to the reaction force of a spring that tends to restore the material to its original undeformed state. In liquids and gases, only deformations that change the volume generate persistent elastic stress. However, if the deformation is gradually changing with time, even in fluids there will usually be some viscous stress, opposing that change. Elastic and viscous stresses are usually combined under the name mechanical stress.

CHAPTER 4

FEASIBILITY STUDY

4.1 Case study

Based on the journals Power Generation Footstep by Shiraz Afzal,etal, and Proposed Method of Foot Step Power Generation Using Piezo Electric Sensor by Mr. A. Adhithan,etal,the feasibility of adopting power generation from footsteps is discussed.

4.2 Study area

The feasibility test of kinetic footfall was conducted at Time Square in New York City. Times Square is a major commercial intersection and neighborhood in Midtown Manhattan, New York City, at the junction of Broadway and Seventh Avenue, and stretching from West 42nd to West 47th Streets. With latitude and longitude coordinates: 40.758896, -73.985130.

4.3 Calculations and feasibility

The idea is to place pavegen tiles throughout Time square on the sidewalks. Since Time square gets roughly 350,000 pedestrians every day, it would make sense to put these on the sidewalks to generate a little electricity,.On average a pedestrian in New York City will walk approximately one mile a day or around 20 blocks. If we assume that each person who goes through Time Square walks one mile, the number of total steps taken is equal to around 650 million steps per day. This is calculated by multiplying the number of pedestrians, 350,000, by 5280 feet per mile and dividing that by 2.5ft per step. Pavegen tells us that each of their blocks will produce 7 watts per impulse of a step, which is 0.68 seconds when measured. This produces 4.76 Joules per step of energy. Multiplying this by the number of steps total for one day and then for one year, the amount of energy produced for one year is 1,105GJ. This is equal to about 307,000 kWh per year of electricity produced. If we assume that electricity costs $0.15 per kWh, the total savings of installing the tiles is $46,042 per year. Unfortunately, each tile costs well over $100 at the moment, and to cover all of Time Square's sidewalks with these tiles, needing around 236,000 of them, it would cost upwards of $23 million dollars. The number of tiles needed was calculated by knowing the area of each tile from Pavegen's website, and calculating the total area of sidewalk within Time's Square. This was done by assuming that each sidewalk is roughly 12 feet in width and then using Google Maps to determine how much sidewalk is in Time Square. The square footage of sidewalk estimated to be in Times Square is roughly 686,500 ft square.

In Time Square during the New Years Eve Celebration. The number of people that come to Time Square for the celebration is approximately one million. Plus, the area in which they are all moving around is much smaller than all of Times Square. Assuming that the area in which the one million people are is equal to a right triangle with lengths of 1500ft and 250ft, roughly half the area of 2 city blocks, and that each person again walks an estimated one mile total, the number of total steps taken for that night is 2.1 billion. The dimensions for the area of the celebration was gotten by using Google Maps and estimating the area as accurately as possible. With that many steps, the amount of power generated is equal to 14.8 million kW. Lets also assume that the celebration goes on from 7pm to 1am, or six hours, and therefore the number of kWh generated is equal to 2792 kWh.

4.3.1 Market Analysis

Energy harvesting (EH) has become a major area of focus in Europe and North America; Asian organizations too are investing in the various EH technologies. By 2020, the global energy harvesting market is expected to reach $4.4bn.

Majority of the sustainable energy technologies calls for a constant monitoring of, the surrounding environment of installation location. Further, the suitable type and specifications of the devices has to be decided based on the survey reports. Parameters such as size of the devices and place of installation also mandate the tedious, time and effort-consuming post-installation monitoring and maintenance tasks.

In contrast to other technologies for which locations are decided based on surveys conducted over a prolonged period, energy harvesting floors eliminate any pre-installation analyzing or monitoring to identify the ideal location. The sole criterion to be fulfilled for the installation is that the place should have human movement. Every city around the world has a huge, growing population, and public places like airports, railway stations and commercial complexes receive huge amount of footfalls throughout the day, thus making them suitable for energy harvesting floors

Energy harvesting tiles started off as prototypes in the beginning of the last decade; significant developments have given them a capability to produce up to 20 watts per hit and about 10 kilowatt-hours in a week. With the support from environmentalists, these tiles have become a runaway success around the world.

4.3.2 IP Perspective

The footfall energy harvesting floor technology came into existence in the mid of 20th century. However, it has received increased attention in the last few years, which is evident from a considerable increase in the number of patent filings in the piezoelectric sector. The traditional lead zirconatetitanate PZT ceramic is being replaced with organic alternatives such as polyvinylidenedifluoride. In addition to creating piezoelectric systems with enhanced efficiency and temperature performance, companies also lay emphasis on the flexibility of the materials.

Companies such as Toyota Boshoku Corp, Pavegen, Seratech, Hong Kong Applied Science and Technology Research Institute Co Ltd are prominent players in energy harvesting floors. Below is a comparative split of patents/publications owned by the players:

Source:www.carbonbrief.org

Fig.4.1. Assignee analysis

Source:www.carbonbrief.org

Fig.4.2 Product analysis

UK-based Pavegen has installed tiles in more than 100 locations, including Harrods and Heathrow Airport. In 2015 the startup raised £2 million from over 1,500 investors on equity crowdfunding platform Crowdcube.

4.3 Future Aspects

In future aspects we can use this principal in the speed breakers at high ways where are rushes of the vehicles too much thus increase input torque and ultimate output of generator. If this project is implemented at very busy stairs palace then we produce efficient useful electrical for large purpose.

4.4 Advantages

To store the electricity in battery.
It can be use at any time when it necessary.
Easy construction.
Less number of parts required.
Electricity can used for many purposes

4.5 Applications

In street light.
In LED light for specific purposes.
In air circulation system for room by the small fans.
For used in security alarm
This can be implemented on railway station to generate elec-tric power.
In bus station.
In car parking system.
In Airports.
In Lift system.
In car lifting system.
Electric escalators

PAGE

POWER GENERATION FROM FOOTSTEPS (Page 2)

2017-01-11T10:03:00.000-08:00

Page 1

CHAPTER 2

THEORETICAL BACKGROUND

2.1 General

With the electronic devices becoming integral part of day-to-day life, both in personal and industrial environments, the demand for energy is tremendously increasing across the globe. In the effort to find alternative sources to supplement the conventional energy sources, the energy industry has found the feasibility in fossil fuels, nuclear, thermal, hydro, solar etc. Human body generates a lot of energy while doing the most-common activity - walking. Every foot fall causes pressure when the foot hits the floor, which goes untapped. With the ground surface engineered to harvest the energy, power can be generated from the human footfalls, stored and used as a power source or even fed to the power grid. For instance, a person dancing on an energy harvesting floor can generate 5-10 watts; in a packed dance club, the production can meet up to 60% of the total energy required for the club.

There are few methods to generate electrical energy from footsteps. Power would be generated by footsteps of crowd on the floor.

2.2 Footfall energy harvesting floor

An emerging startup called Pavegen has installed such squares of energy-generating pavement in London. In an effort to keep the production of the pavement as green and sustainable as possible, Pavegen partnered with Ryburn Rubber Limited and Advanced LEDs (which has also invested in the idea) to make sure that its components create as small an environmental impact as possible.The average square of pavement produces about 2.1 watts of electricity. And according to Pavegen, any one square of pavement in a high-foot traffic area can see 50,000 steps a day. Based on this data, only five units of Pavegen pavement can be enough to keep the lights on at a bus stop all night .

And while the power producing platform is over crowded with moving population, energy is produced at larger levels. Pavegen isn’t targeting its product exclusively at municipalities. One of its big ideas is to have stores located on busy sidewalks install them in front of their locations to power their signage or any internal electronics. To encourage this adoption, the company says it will brand its slabs for its commercial customers. The slabs installed in East London happen to be green (thus suggesting its clean-tech solution) but they come in a variety of colors . The company believes the embedded lamp is important to inform passersby of their contribution to the clean energy movement.

An emerging technology in the industry is the footfall energy harvesting floor, which generates energy from the routine human activities, such as walking, running, jumping, dancing etc. The technology works on the basic principle of converting kinetic energy, obtained from the pressure applied on the floor surface, into electrical energy. The “footfall energy harvesting floor” comprises a floor covering that encloses a transducer mechanism for converting the applied pressure into electrical energy and a means for transmitting the electrical energy for storage or load consumption. Among the other technologies that promote sustainable energy, energy harvesting floor is considered to be the most productive as it does not depend on any of the natural resources, such as wind, water or sun that are not consistently available. Energy harvesting floors, which take input from human footsteps without affecting pedestrians’ normal life, are easy to install, environment friendly, and are truly sustainable.

2.3 Experiments with energy harvesting floors

Researches and developers have experimented on footfall energy harvesting floors to study their feasibility, reliability and effectiveness. Constant experiments have been carried out in the East Japan railway stations, streets of Toulouse and West Ham underground station over a period of varying durations, ranging from several weeks to few years. These experiments have provided evidences that energy harvesting tiles are robust, practical and can be used as an alternative source of producing energy. Post the initial success, improvements are being made and tested for enhanced power generation performance and capacity, along with advancements in material durability. The energy thus captured can be used to power streetlights, pedestrian crossing lights, bus stop displays, traffic signals, automatic ticket gates in stations, information displays etc. Dance clubs around the globe have piloted the footfall energy harvesting floors belonging to the prototype concept - "Crowd Farm", in which energy from footfalls of clubbers dancing on the floors is collected and used to power LED lights and, in the long-term plan, fed into the club's power grid.

2.4 Different technology behind the energy floors

With this method energy harvesting proving its feasibility, developers of energy harvesting floors concentrating their efforts find the most-efficient way of harvesting energy from footfalls. To popularize and establish this technology among varied consumer segment, inventors have already initiated marketing of their products, which has been well received by environmental activists. Based on the mechanism used for converting the kinetic energy into electrical energy, footfall energy harvesting floors can be broadly classified into the following categories:

Source: Wikipedia

Fig.2.1. Different methods for power generation from footsteps

Table 2.1 Different methods for power generation from footsteps

2.4.1 Piezoelectric method for power generation

Though various kinds of footfall energy harvesting technologies exist, piezoelectric is the commonly-used technology. It generates energy from external force impulses or vibration in flooring, bridges, roads and structures. This system can produce energy even with consistent or predictable vibrational frequency. With its ability to leverage any kind of force, stress or strain, it is ideal for different applications, and hence has a widening market potential.

Though, power generated using piezoelectric systems are predominantly in cigar lighters, they have found applications in wireless sensors and various portable electronics.

However, the varying or inconsistent vibrational frequency range limits the practicality for certain applications.This device, if embedded in the footpath, can convert foot impact energy into electrical form. The working principle is simple. When a pedestrian steps on the topplate of the device, the plate will dip down slightly due to the weight of the pedestrian. The downward movement of the plate results in rotation of the shaft of an electrical alternator, fitted in the device, to produce electrical energy. The top plate reverts back to its original position due to negating springs provided in the device. If such devices are embedded in places where there is continuous human traffic such as in city malls, railway platforms, city footpaths etc., the electricity generated from these devices can be used for street lights.

The greatest attraction of this technique is that in order to generate electrical power using footsteps one step will be enough at this level to produced electrical energy. The piezo electric method can be approached as a fly and gear wheel mechanism. Following are the steps of fly and gear wheel method.

First step is by proper arrangement of electrical system. After the arrangement of electrical system which transforms mechanical energy to electrical energy, When a human steps on the device due to his/her body weight the iron plate moves downwards and drives the crank shaft which further drives the gear arrangements which further drives fly wheel. Then there is another gear arrangement which is connected to the commentator of the dynamometer. The load is applied in the iron plate, Power is produced. Then the voltage that produced through steps is rectified and after battery charger circuit this D.C voltage is stored in the lead acid battery of 12 volt. This lead acid battery is further attached to the inverter. The invert is designed such that it inverts the voltage from battery which is 12 volt D.C to 230 volt A.C. So this A.C voltage is used in different appliances such as for charging the laptop battery and also to charge the handset, it can also be used to lightening up through energy saver. In order to produce more power the number or footsteps can be increased and also the ability of battery and inverter should be increased, then output power will also be increased.

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POWER GENERATION FROM FOOTSTEPS

2017-01-11T10:01:00.000-08:00

By Anjali Salimkumar

Page 1

ABSTRACT

This seminar is all about generating electricity when people walk on the Floor. Think about the forces you exert which is wasted when a person walks. The idea is to convert this force to electrical energy. The Power Generating floor intends to translate the kinetic energy to the electrical power. Energy Crisis is the main issue of world these days.

The motto of this research work is to face this crisis somehow. Though it won’t meet the requirement of electricity but as a matter of fact if we are able to design a power generating floor that can produce 100W on just 12 steps, then for 120 steps we can produce 1000 Watt and if we install such type of 100 floors with this system then it can produce 1MegaWatt. Which itself is an achievement to make it significant

CHAPTER 1

INTRODUCTION

Energy is very important in today's world. For example, we use different energy sources to generate the electricity we need for our homes, schools, businesses and factories. Electricity powers our TVs, computers, air conditioners, cell phones and washing machines - just to mention a few. We also use energy to run cars, planes, trains, buses and motorcycles.Energy harvesting also known as power harvesting or energy scavenging is the process by which energy is derived from external sources e.g. solar power, thermal energy, wind energy, salinity gradients ,and kinetic energy, captured, and stored for small, wireless autonomous devices, like those used in wearable electronics and wireless sensor networks. Energy harvesters provide a very small amount of power for low energy electronics. While the input fuel to some largescale generation costs money (oil, coal, etc.), the energy source for energy harvesters is present as ambient background and is free. For example, temperature gradients exist from the operation of a combustion engine and in urban areas, there is a large amount of electromagnetic energy in the environment because of radio and television broadcasting.

Walking is the most common activity in day to day life. When a person walks, he loses energy to the road surface in the form of impact, vibration, sound etc, due to the transfer of his weight on to the road surface, through foot falls on the ground during every step. This energy can be tapped and converted in the usable form such as in electrical form

With that in mind investments are being made in the popular green energy sectors such as wind, solar, and wave energy. However, people’s steps (thousands upon thousands a day) utilize and channel kinetic energy too.

1.1 Objective

The objective of this study is to find the feasibility of power generation from footsteps.

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WATER TREATMENT USING MORINGAOLEIFERA (Page 4)

2017-01-11T10:00:00.000-08:00

Page 4

CHAPTER 4

CASE STUDY

4.1 INTRODUCTION

About 75% of the present world population lives in the developing countries of the world. About 1.2 billion people still lack safe drinking water and more than 6 million children die from diarrhea in developing countries every year.

Safe drinking water is essential to the health and welfare of a community, and water from all sources must have some form of purification before consumption. Various methods are used to make water safe and attractive to the consumer. The method employed depends on the character of the raw water.

Coagulation-flocculation followed by sedimentation, filtration and disinfection, often by chlorine, is used worldwide in the water treatment industry before distribution of treated water to consumers. Naturally occurring coagulants are usually presumed safe for human health while there is a fear by using aluminum salts that may induce Alzheimer’s disease.

Moringaoleifera is one of the most wide spread plant species that grows quickly at low altitudes in the whole tropical belt, including arid zones. It can grow on medium soils having relatively low humidity. Moringaoleifera seeds are an organic natural polymer.

Jahn (1984) has presented Moringaoleifera as a coagulant after her studies in the Sudan (Jahn, S.A.A. 1984; Jahn, S.A.A. 1988) when she noticed that Sudanese village women used it at home to clear the turbid Nile water. Later, many researchers have reported on the various uses of Moringaoleifera seeds as coagulant and coagulant aid in the last 20 years. Moringaoleifera coagulant has been found to have high coagulation activity only for high turbidity water. The activity is low for low turbid water (Muyibi, S. A. and Evison L.M., 1995). Therefore, it is important to improve the characteristics of this plant by identifying its bioactive constituents, which has high coagulation activity. This is one of the objectives of this study.

4.2 METHODOLOGY

4.2.1 Materials

Dry Moringaoleifera seeds used in this study were collected from gardeners in Serdang area, Selangor Darul Ehsan, Malaysia. The extraction of oil carried out by electro thermal Soxhlet using hexane. The bioactive constituents were extracted from Moringaoleifera using phosphate buffer (0.1M), jar test for measuring coagulation activity, turbidimeter for turbidity measurements, and the river water samples (low, medium, and high turbidity from Sungai Pusu, International Islamic University Malaysia) were collected to apply jar test.

4.2.2 Oil Extraction

The extraction of oil carried out by electro thermal Soxhlet using hexane. The oil percentage was 35% w/w. The dried cake was used in this study while the oil kept for other research work.

4.2.3 Extraction of bioactive constituents

Weighing of 10gm of Moringaoleifera cake, adding of 100ml of phosphate buffer (0.1M) with pH 7.5, mix with gentle stirring at 4ºC for 2hours to extract the bioactive constituents, then centrifuge the contents at 6000 rpm for 30 min, the supernatant was injected to the Ion Exchange column to separate the bioactive constituents.

4.2.4 Jar Test

Jar test for measuring coagulation activity, turbidimeter for turbidity measurements, and the river water samples (low, medium, and high turbidity from Sungai Pusu, IIUM) were used to apply jar test. The turbidity for river water samples were 43.9, 91, and 333 for low, medium and high turbidity, respectively.

Fig.4.1: Jar test for high turbidity river water

(Source: Eman N Ali (2009))

4.3 RESULTS AND DISCUSSION

The processed Moringaoleifera was improved by isolation of bioactive constituents from the seeds as a coagulant/flocculant which gave turbidity removal of 95.5%, 98.5%, and 99.3% for the treatment of river water with low, medium and high turbidity, respectively and by using the dosage tabulated in Table 1.

The results showed that the dosage of coagulant to be added was decreased which means decreasing of sludge volume produced (which consider as one of the main problems associated with using aluminum salts and as a sequence need to be treated with more chemicals).

The residual turbidity for all samples was lower than 5NTU, which is the standard setby WHO for drinking water.

Table.4.1: Jar test results (Source: Eman N Ali,(2009))

Moringaoleifera can be used as a natural coagulant/flocculants alternative to the aluminum and other metallic salts.

CHAPTER 5

CONCLUSION

Moringaoleiferais an environmentally-friendly natural coagulant most suitable for the treatment of water containing undesirable heavy metal concentrations. Based on the experimental test results; the following conclusion can be drawn.

1. The optimum dosage of Moringaoleifera aqueous extract for synthetic water samples containing heavy metal concentrations of 5mg/L was 2g/L and the removal efficiencies were 95%, 93%, 76% and 70% of copper, lead, cadmium and chromium respectively.

2. The process of up flow roughing filtration followed by rapid filtration is suitable for the separation of the flocs formed using Moringaoleifera seed coagulant.

3. It is an eco-friendly technology that is economically more advantageous than other treatment alternatives.

4. In accordance with the above conclusions, it is suggested that aqueous extract of Moringaoleifera seed powder treatment with coagulation and flocculation followed by double filtration (roughing filters followed by rapid filtration) is considered in the event of expansion or construction of small scale waterworks, presuming that an adequate amount of plantations are established.

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WATER TREATMENT USING MORINGAOLEIFERA (Page 3)

2017-01-11T09:59:00.000-08:00

Page 3

CHAPTER 3

RESULTS AND DISCUSSIONS

3.1 REDUCTION IN TURBIDITY

The jar test operations using MO coagulant were carried out in different turbidity ranges namely higher- (90–120) NTU, medium- (40–50) NTU, and lower- (25–35) NTU of synthetic turbid water. The efficiency of the extract of Moringaoleifera, made them used as natural coagulants for the clarification of water. Doses started from 50 mg/L to 100 mg/L for corresponding six beakers. Turbidity was measured before and after treatment. Moringaoleifera works well in higher-turbidity water than lower and medium-turbidity water. Turbidity reduction increases with increasing doses.

Fig 3.1:Removal of turbidity using various doses of Moringaoleifera

(Source: Wikipedia)

3.2 COAGULANT ACTIVITY TEST RESULTS OF SYNTHETIC WATER SAMPLES CONTAINING HEAVY METALS

Coagulation- flocculation was done using shelled blended, oil extracted and crude extract of Moringaoleifera seed powder. Thesecoagulants were extracted by using a standard preparation method.Optimum doses of 2 g/L coagulants were used for different water samples containing heavy metals concentrations of 5 mg/l. The optimumdosage is the minimum dosage of coagulant corresponding tothe removal of heavy metals present in the water samples. At optimumdosage of 2 g/L of coagulant, the final heavy metal concentrationsreduced considerably, in all foursynthetic heavy metal water samples as shown in Table 3.1.

Table 3.1:Final heavy metal concentrations and the respective increase in turbidity levels after coagulation treatment with filtrated Moringaoleifera coagulant.

(Source: Ravikumar K and Prof. Sheeja A K (2013))

3.3 TEST RESULTS OF SYNTHETIC HEAVY METAL WATER SAMPLES AFTER UPFLOW ROUGHING FILTRATION

Samples of water collected from the outlet of roughing filter were used for analyzing the turbidity and heavy metals. Table 3.2 represents the results of turbidity removal from treated water with various heavy metals of concentration 5mg/l, after upflow roughing filtration. An up-flow roughing filtration stage was chosen because it is a process with a high efficiency in the removal of light flocs. The bed of the upflow gravel roughing filter was made up of three layers of gravel of different granule measures.

3.4 TEST RESULTS OF SYNTHETIC HEAVY METAL WATER SAMPLES AFTER UPFLOW ROUGHING FILTRATION AND RAPID FILTRATION (DOUBLE FILTRATION)

Samples of water collected from the outlet of rapid filter were used for analyzing the turbidity and heavy metals concentrations. Table 3.2 represents the results of turbidity removal, after upflow roughing filtration and rapid sand filtration (double filtration).

Table 3.2: Turbidity (NTU) after up flow roughing filtration and double filtration

(Source: Ravikumar K and Prof. Sheeja A K (2013))

The combined coagulation and double filtration process is an alternative for heavy removal, since the coagulation process is effective in removing metal ions and double filtration complements the process by reducing the turbidity to the limits.The MO seed powder has been termed as potential heavy metal removing agent due to its oxygen and nitrogen donating carboxylate and amino groups.MO seed powder extraction with salt increased the removal efficiency. The adsorption of metals using MO is limited to the adsorption surface. This is because MO is a cationic polyelectrolyte of short chain and low molecular weight. The mechanism that brings about adsorption of heavy metals is through thepositive metal ions that forms a bridge among the anionic polyelectrolyte and negatively charged protein functional groups on the colloidal particle surface. There is formation of complexes with the heavy metals and the organic matter of MO seeds such as proteins.Due to hydrophilic character, several hydrogen bonds are formed among polyelectrolyte and water molecules. Polyelectrolyte coagulant aid have structures consisting of repeating units of small molecular weight forming molecules of colloidal size that carry electrical charges or ionisable groups that provide bonding surface for the flocs. Adsorption describes attachment of ions and molecules from seed protein by means of specific mechanism. Metal ions in coagulation react with proteins and destroy them in water. Metal adsorption occurs due to the high protein content of the seeds. The flocculation activities of MO seeds are based on the electrostatic patch charge mechanism. Studies have shown that seeds have the capability to adsorb metal cations and attract highly toxic compounds.

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WATER TREATMENT USING MORINGAOLEIFERA (Page 2)

2017-01-11T09:57:00.000-08:00

Page 2

CHAPTER 2

MATERIALS AND METHODS

2.1 MORINGA OLEIFERA

Moringaoleifera (MO), known as Moringa, is full of nutrients and vitamins and is good in your food as well as in the food of your animals. Moringa helps to clean dirty Water and is a useful source of medicines.

Fig.2.1: Moringaoleifera Tree

(Source: Eman N Ali (2009))

2.2 PREPERATION MORINGA OLEIFERA SEED POWDER

Good quality dry seeds of Moringaoleifera were selected from the pods that were collected. The pods collected were allowed to completely dry on the tree (the brown colour pods) because the green pods do not possess any coagulation activity.

The pods length ranged between (40-60) cm, and each pod contained around (20-30) seeds. The seeds coat and wings were removed manually, followed by the grinding of the seeds into a fine powder using a domestic blender, then sieving the ground powder through 250 μm sieve. Figures 2.2, 2.3, 2.4 and 2.5 shows the MO pods, MO seed, de-husked seed kernel and seed powder.

Fig.2.2: Moringaoleifera pods

(Source: Eman N Ali,(2009))

Fig.2.3: Moringaoleifera seeds

(Source: Ravikumar K and Prof. Sheeja A K (2013))

Fig.2.4:Moringaoleifera de-husked seed kernels

(Source: Ravikumar K and Prof. Sheeja A K (2013))

Fig.2.5: Moringaoleifera seed powder

(Source: Ravikumar K and Prof. Sheeja A K (2013))

2.3 AQUEOUS EXTRACT

Aqueous extract was prepared by using 200ml of tap water and 25g of MO seed powder, mixed by a magnetic stirrer for 60 minutes and settled for 20 minutes. Moringaoleifer aqueous extract is finally filtered through 20µm paper filter.

2.4 COAGULANT ACTIVITY TEST

Sedimentation Jar test were carried to determine the coagulation properties of the plant derived coagulants. Onebeaker was used as control and in other beakers varying dosage of MO coagulant was added. Jar tests were conductedon 1000 ml synthetic turbid water samples.The standard procedure was, the samples were subjected to a rapid mixing at 100 rpm for 1 minute, and a slow mixing step at 30 rpm for30 min. The stirrer was then switched off and the flock allowed to settle undisturbed for 30 minutes. The samplesfor residual turbidity measurement were withdrawn using a pipette from a height of 5cm below the surface of eachbeaker, and residual turbidity was measured. Effect of dose of natural coagulants on removal of turbidity alsostudied. Jar test also determines the effective dosage of coagulant to reduce the heavy metal of the sample.

The effect of pH on turbidity removal was also studied by varying pH of turbid water. pH of the suspension wasadjusted to the desired value by adding either 0.1 MHCl solution or 0.1M NaOH solution. Turbidity measurementwas carriedout by ‘GlobeInstrument’ Turbidity meter.pH value of the suspensionwas measured using a pH model meter.

2.5 MULTISTAGE DRINKING WATER FILTRATION

By providing roughing filter pretreatment, suspended solids are decreased. Rapid sand filtration is still a viable method of water treatment most suitable for raw water sources with turbidity and suspended solids. Multistage filtration has been shown to be an efficient and effective drinking water treatment technique for source water with high turbidity, organic matter, and suspended solids.

2.5.1 FILTRATION TEST WITH ROUGHING FILTERS

In vertical-flow roughing filters the water to be treated flows in sequence through the three filter compartments filled with coarse, medium and fine filter material. The size of the three distinct filter material fractions is generally between 25 and 3 mm, and graded, for example, into fractions of 25-16mm, 16-8mm and 8-3mm. Roughing filtration was conducted directly after the coagulation and flocculation processes with Moringaoleifera and separates the suspended solids. Vertical-flow roughing filter was operated at 0.3 to 1.0 m/h filtration rates. The separated solids, which accumulate mainly in the coarse filter fraction next to the filter bottom, can be easily flushed out with the water stored in the filter. Therefore, the use of upflow roughing filter in layers was used.

Fig.2.6: Up flow roughing filters

(Source: Ravikumar K and Prof. Sheeja A K (2013))

2.5.2 Filtration test with rapid sand filter

In rapid sand filters the water to be treated flows in sequence through the three filter compartments filled with coarse, medium and fine filter material. The size of the three distinct filter material fractions is generally between 50 and 0.5 mm, and graded, for example, into fractions of 25-50mm, 13-25mm and 0.5-1mm. Rapid sand filtration was conducted directly after the roughing filtration and separates the last remaining flocs that failed to disappear during roughing filtration. The filtration rate for a rapid filter is 5-10 m/h.

Fig.2.7: Rapid sand filter media size

(Source: Ravikumar K and Prof. Sheeja A K (2013))

2.5.3 Moringaoleifera seed coagulation and double filtration

Double filtration is an efficient and effective drinking water treatment technique for source water with high turbidity,organic matter, and suspended solids.Jar tests were carried out in the following conditions: 1 minute rapid mixing and 10 minutes slow mixing. An up-flow roughing filtration stage was chosen because it is a process with a high efficiency in the removal of light flocs. As a second stage a conventional rapid filter was adopted.

The washing of the roughing filter was carried out through lower drainage, and the washing of the rapid filter was counter current. The bed of the upflow gravel roughing filter was made up of three layers of gravel of different granule measures.

Fig.2.8: Moringaoleifera coagulation and double filtration

(Source: Ravikumar K and Prof. Sheeja A K (2013))

PAGE

WATER TREATMENT USING MORINGAOLEIFERA

2017-01-11T09:43:00.000-08:00

By Anjali B

Page 1

CHAPTER 1

INTRODUCTION

Water supply is a basic need required for living creatures and human beings. Safe drinking water is essential to the health and welfare of a community, and water from all sources must have some form of purification before consumption.The method employed depends on the character of the raw water. One of the problems with treatment of surface water is the large seasonal variation in turbidity.

For many developing countries water treatment process involves coagulation, flocculation and sedimentation (which are the processes involved in removing turbidity from water) and disinfection are expensive processes because of the high costs involved and the difficulty in assessing the chemical coagulants including alum.Inorganic coagulants such as alum in combination with lime have been conventionally used for removal of turbidity from surface waters. The sludge formed from such treatment poses disposal problems because of its aluminium content and tend to accumulate in the environment and also because of large volume.Therefore, it is desirable that other cost effective and more environmentally acceptable alternative coagulants be developed to supplement if not replace alum, ferric salts and synthetic polymers. However, there have been studies on the use of indigenous natural coagulants. The use of locally grown and natural coagulants may result in a more sustainable and economically available alternative.

The history of the use of natural coagulants is long. Natural organic polymers have been used for more than 2000 years in India, Africa, and China as effective coagulants and coagulant aids at high water turbidities. They may be manufactured from plant seeds, leaves, and roots. These natural organic polymers are interesting because, comparative to the use of synthetic organic polymers containing acrylamide monomers, there is no human health danger and the cost of these natural coagulants would be less expensive than the conventional chemicals alike since it is locally available in most rural communities of Bangladesh. A number of effective coagulants from plant origin have been identified.

The need for simple, reliable and effective method of water treatment leads to the application of plant materials, including seed coagulants of Moringaoleifera. The Moringaoleifera tree grows in tropical and subtropical regions around the world and its seed have been used in drinking water treatment in small scale. Previous studies indicate that Moringaoleifera is an efficient coagulant for the removal of turbidity in both water and waste water treatment.

The Moringaoleifera is an alternative to the use of inorganic and synthetic coagulants.Disadvantages of inorganic and synthetic coagulants are it cause Alzheimer’s disease and similar health related problems, reduction of pH,high costs production of large sludge volume and low efficiency in coagulation of cold water. Moringaoleifera has potential in water treatment as a coagulant,a soften agent and bactericidal agent. Advantages of Moringaoleifera as a natural coagulant are its low cost,produces lesser volume of biodegradable sludge and it does not affect the pH of water.

Moringaoleifera seeds contain a coagulant protein that can be used either in drinking water clarification or wastewater treatment. It is said to be one of the most effective natural coagulants and the investigation on these kinds of water treatment agents is growing nowadays.

The Moringaoleifera is not used in field because of the some drawbacks of Moringaoleifera as it requires large amounts of seeds for small water treatment plant. Also the settling time is more. If the blended coagulant of Moringaoleifera& alum is used then the drawbacks of alum and Moringaoleifera is reduced and this blend coagulant gives best results, means it removes almost 99.4 % the turbidity. Heavy metals are also present in water which is hazardous to health. Moringaoleifera seed coagulant with double filtration also helps in the removal of heavy metals.

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CHAPTER 6

CASE STUDY

It has become evident in recent times that base isolation can be very effective in the event of an earthquake. The cost of installing base isolation systems has been so great that it is generally only used for emergency centres, historical buildings, and buildings housing very expensive and sensitive equipment and are limited to developed nations only and in a developing country like India, base isolation technique is as good as nonexistent. Having technological &research institutes in almost every part of a country, still research in this field is limited to few IITs only. The only instance of base isolation in India is at district hospital constructed post 2001 Bhuj earthquake incorporating lead rubber bearing system Cost involved in constructing a new building is higher than the cost of conventional earthquake resistant structural system. Seismic isolation bearings are expensive. Due to these economic considerations, even in developed countries these devices have so far been used for important buildings only. To enable its use for common buildings, some low cost devices have to be developed.

Fig. 6.1.Time Period of base isolated & non base isolated on soft & stiff soil.

(Source: S. J. Patil, G. R. Reddy Website: www.ijetae.com)

Soft soil ground condition isn’t suitable for base-isolated structures. After LRB yield, the structure period corresponding to the equivalent linear stiffness can be further prolonged. As a result, the natural period just enters into the range of the predominant period of earthquake wave. It leads to the acceleration amplification which makes the enlargement of seismic energy response. Consequently, it should be paid much attention on the design of absorption and isolation for base-isolated structures under the soft soil ground condition.

Requirement of tests on prototype bearing of every type increases the cost of the project. Therefore, development and standardization of testing methods for evaluating the properties of isolation devices should be formulated.

Fig. 6.2. Rubber bearing provided to Bhuj hospital.

(Source: S. J. Patil, G. R. Reddy Website: www.ijetae.com)

Fig. 6.3. Indian scenario for base isolation

(Source: S. J. Patil, G. R. Reddy Website: www.ijetae.com)

But however some low cost isolation devices can be incorporated to ordinary structures situated in high seismic zones, especially to structures from rural regions where maximum part of a India’s population dwells. Of course, these low cost isolation devices, can never met the performance level as those of high end devices like LBR, FPS etc but can be of great help in minimizing number of casualties during major seismic events.

Some examples of low cost isolation system include rubber bearings reinforced with fibre glass mesh instead of steel(this reduces weight as well as cost of the bearings to great extend.

Fig. 6.4. Scrap tyre pad as low cost isolator device

(Source: Pallavi WamanraoTaywade, Madhuri Narayan Savale)

Scrap rubber tyre pads can also be utilized for isolating a building. Since the tires are being designed for friction, load transfer between scrap tire layers would be large enough to keep all layers intact. A minimal slip generated between the piled layers at high strain rates may even help to dissipate some extra energy. Steel mesh in tyre can be assumed to provide vertical rigidity to an extent. Rectangular shaped layers cut from tread sections of used tires and then piled on top of each other to form Scrap Tire Pad (STP) can function as an elastomeric pad.

CHAPTER 7

CONCLUSION

Seismic base isolation method has proved to be a reliable method of earthquake resistant Design. The success of this method is largely attributed to the development of isolation devices and proper planning. Different types of isolation devices have been proposed and extensive research has been made on them.

They can serve the purpose for almost all types of conditions. Adaptable isolation systems are required to be effective during a wide range of seismic events. Besides, the existing devices are expensive and to make isolation feasible for ordinary buildings, it is efforts are required to develop cost effective devices.

REFERENCES

[1]. Pallavi Wamanrao Taywade, Madhuri Narayan Savale.“International Journal of Innovative Research in Science, Engineering and Technology ”(An ISO 3297: 2007 Certified Organization) Vol. 4, Issue 3, March 2015, pp 1215-1228

[2]. S. J. Patil, G.R.Reddy.“International Journal of Emerging Technology and Advanced Engineering” Website: www.ijetae.com (ISSN 2250-2459), Volume 2, Issue 7, July 2012, pp438-453

[3]. J. Appl. “Sci. Environ. Manage. ” Vol. 16, Dec, 2012, pp 299 -307

[4]. Dr. R. S. Talikoti, Mr. Vinod R. Thorat, “International Journal of Engineering Research & Technology (IJERT)” ISSN: 2278-0181 www.ijert.org Vol. 3 Issue 7, July – 2014, pp 863-868

[5]. M. Botis,C. Harbic.“Bulletin of the Transilvania University of Brasov Series I: Engineering Sciences” Vol. 5 (54) No. 1 – 2012, pp93-98

[6]. Hossein Monfared, Ayoub Shirvani, Sunny Nwaubani.“ International Journal of Civil and Structural Engineering”Volume 3, No 3, 2013, pp 451-463

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CHAPTER 4

FUTURE TRENDS IN BASE ISOLATION

Many of the base isolation techniques described above involve the materials, which are susceptible to deterioration with time. Regular inspection and maintenance of the system is required. Special measures need to be taken for fire protection. As such it is desirable to develop such an isolator, which has a life span equal to the life of a structure, free from effects of environment and fire. Also it should be free from maintenance. Hence it will be an ideal case if researchers develop an isolator using materials which are unaffected by environment or affected by it to very low extent like natural earth of specific qualities having inherent properties of spring action and friction.

The equivalent spring constants and damping co-efficient for foundations resting on soil can be worked out using equations given in the table (4.1). Equations for damping accounts for material as well as radiation effects.

From the equations which are valid for low strains, it can be seen that the spring stiffness is more for large size foundations and for greater value of shear modulus G. Also it is dependent on Poisson’s ratio of soil. Thus the spring values of the soil can be altered by varying the above parameters by choosing soil of appropriate properties. In similar way the damping properties of the soil medium can be altered. Also the effect of damping and isolation can be obtained by allowing the structure to slide on a soil medium to required extent. However, in the case of using soft geological materials such as soil, sand, pulverised granite etc, the material will see large strains.

Table 4.1.Spring constant and damping coefficients

for foundation on homogeneous half space

(Source: S. J. Patil, G. R. Reddy Website: www.ijetae.com)

Where -

Ρ = mass density of soil

Vs = Shear wave velocity of soil medium

G = ρ Vs2

ν = Poisson’s ratio of soil medium

R = equivalent radius for rectangular foundation (R= √BL/π for translation and R= 4√4BL3 / 3π for rocking).

B = width of the foundation perpendicular to the direction of horizontal excitation

L = length of the foundation in the direction of horizontal excitation

I0 = total mass moment of inertia of structure and foundation about the rocking axis at the base

IT = polar mass moment of inertia of structure and foundation

βx, βψ, and βv are constants depending on ratio L/B

C1= 0.5 ; C2 =0.30/(1+ βψ); C3 = 0.8

CHAPTER 5

ADVANTAGES & LIMITATIONS

5.1. Advantages

• Structural Damage is restricted when the structure is built on a suitable seismic isolating system.

• Damage to indoor services and facilities would be of little concern which would normally affect gas, water or swage leakage for unfortified structures. The base Isolation will protect the structure by preventing plastic deformation of structural elements, because, the super-structure demonstrates elastic behaviour during initial and following excitation of the base.

• Secondary damage and injury as a result of falling furniture would be restricted. In the other words, the level of safety is increased significantly when using base isolation system rather than conventional systems.

• The function of buildings can be ensured during an excitation or even after a major earthquake as super-structure is designed to remain elastic. Therefore, plastic deformation of structural elements can be prevented and the building is still a safe place to remain and life can continue as normal.

• Evacuation routes and corridors are normally secured in a base-isolated building after an earthquake so, horror of earthquake can be eased and psychological burden is alleviated.

• Reduction in earthquake input forces, coul lead to slender structural elements and consequently the considerable reduction in the whole weight of structure, which givesthe noteworthy reduction in construction materials and construction costs.

• Considerable safety improvements would reduce disaster management protocol for such buildings during an earthquake and reduction of repair costs after an earthquake, seismic isolation can reduce life cycle cost.

5.2. Limitations

Base isolation enables the reduction in earthquake-induced forces by lengthening the period of vibration of the structure. However, Base isolation is not suitable for all buildings. Most suitable candidates for base-isolation are low to medium-rise buildings rested on hard soil underneath; high-rise buildings or buildings rested on soft soil are not suitable for base isolation.. Period of vibration in building increases with increasing height. Taller buildings reach a limit at which the natural period is long enough to attract low earthquake forces without isolation. Therefore, seismic isolation is most applicable to low and medium rise buildings and becomes less effective for tall ones. The cut off mainly depends on structural systems or type of framing system. Cost involved in constructing a new building is higher than the cost of conventional earthquake resistant structural system. Seismic isolation bearings are expensive. Due to these economic considerations, even in developed countries these devices have so far been used for important buildings only. To enable its use for common buildings, some low cost devices have to be developed.

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CHAPTER 3

BASE ISOLATION TECHNIQUES

In traditional seismic design approach, strength of the structure is suitably adjusted to resist the earthquake forces. In base isolation technique approach, the structure is essentially decoupled from earthquake ground motions by providing separate isolation devices between the base of the structure and its foundation. The main purpose of the base isolation device is to attenuate the horizontal acceleration transmitted to the superstructure. All the base isolation systems have certain features in common. They have flexibility and energy absorbing capacity. The main concept of base isolation is to shift the fundamental period of the structure out of the range of dominant earthquake energy frequencies and increasing the energy absorbing capability.

Presently base isolation techniques are mainly categorized into three types viz. Passive base isolation techniques, Hybrid isolation with semi-active devices and Hybrid base isolation with passive energy dissipaters. These different techniques are discussed in short below –

3.1. Passive base isolation techniques

Various passive base isolation techniques are,

3.1.1 Mud layer below the structure

Frank Lloyed Wright was the first person who implemented the idea of base isolation technique for isolating Imperial Hotel structure in Tokyo, by providing closely spaced short length piles in 8 feet thick soil layer underlain by a thickness of mud layer over hard strata. The building survived an earthquake in 1923.

3.1.2. Flexible first storey

The flexible first storey concept was first proposed by Martel in 1929 and was further studied by Green in 1935 and Jecobson in 1938 thereby reduce the loading on upper storey members. However, further studies by Chopra et. al.with the aid of computers showed that the concept is impractical. Also the recent earthquakes at Bhuj in India and Kobe in Japan have revealed that most of the buildings with soft storey have suffered extensive damage.

3.1.3. Roller bearings in foundations

Roller bearing systems proposed for isolation of the structures were having serious drawback as the rollers were having to and fro motion in particular direction and earthquake has three directions motion due to which earthquake forces could not be isolated effectively. Also the main problem was that the device needed maintenance for keeping in good operation throughout its working life period. The system was further modified with ball bearing system.

3.1.4. Rubber layer as foundation support

School building in Skopje, Yugoslavia constructed on rubber foundations in 1969, used to bounce and rock forward and backward during earthquake due to uniform stiffness of rubber in all directions. Also the rubber foundation bulged under the weight of the building.

3.1.5. Laminated rubber bearing system

Laminated rubber bearings (LRB) (ref. Fig.3.1), which are made of thin layers of steel plates and rubber built in layers one over the other, have horizontal flexibility, high vertical stiffness and they can be characterized by natural frequency and damping constant.

The main advantages of rubber bearing system are -

• Effective isolation is achieved. It will decrease the structural response to 1/2 -1/8 of the traditional structural response.

• Stable character of isolators over a long working life

• Recovery of the displacement after earthquakes

• Vertical tension capacity is good

• Isolators are insensitive for foundation settlement, which are generally small in magnitude. It could adjust the structure force by deformation of rubber bearings when foundation settlement of building happens before or after earthquakes

• Decreasing the temperature stress in structures by free horizontal deformation of bearings during large change of temperature around the structure

Fig.3.1. Laminated rubber bearing system - a) Sectional details b) Schematic diagram c) Force deformation behavior (source: S. J. Patil, G. R. Reddy Website: www.ijetae.com)

3.1.6 New Zealand bearing system

The system (ref. Fig.3.2), invented in NewZealand in the year 1975, is improved version of laminated rubber bearing wherein a centrally located lead core is introduced, which has energy dissipating capacity. The presence of lead core reduces displacement of the isolator and isolator essentially works as hysteretic damper device. The device has been extensively used in New Zealand, Japan and USA. Buildings isolated with these devices performed well during the 1994 North ridge earthquake and 1995 Kobe earthquake.

Fig. 3.2. New Zealand bearing system (a) Sectional details (b) Schematic diagram (c) Force deformation behavior (source: S. J. Patil, G. R. Reddy Website: www.ijetae.com )

3.1.7. Resilient – friction base isolation system

Resilient – Friction Base Isolation (R-FBI) system (ref. Fig.3.3) proposed by Mostaghel and Khodaverdian consists of concentric layers of Teflon coated plates which will have sliding resistance and a central core of rubber which will have beneficial effect of resilience of a rubber.

3.1.8. Electric de-France system

Electric De-France (EDF) (ref. Fig. 3.4) system is friction type base isolation system developed under the auspices of Electric de France in the year 1970. The system is standardized for Nuclear power plants in the region of high seismicity. The system consists of laminated Neoprene pad topped by a lead bronze plate, which is in frictional contact with steel plate anchored to the base raft of the structure. Therefore its cross section is similar to the LRB system.

The neoprene pad has very low displacement capacity (5 cm approx.) and when this capacity is exceeded, the sliding element provides the needed movement. The system does not include any restoring device and hence permanent displacement could occur. The system has been implemented in nuclear power plant at Koeberg in South Africa.

Fig. 3.3. Resilient – friction base

a) Sectional details

b) Schematic diagram

c) Force deformation behavior

Fig 3.4. Electric De-France (EDF) isolation system

(a)Schematic diagram

(b)Force deformation behavior

(source: S. J. Patil, G. R. Reddy Website: www.ijetae.com)

3.1.9. Sliding resilient- friction system

The design of sliding resilient- friction base isolator (refer fig. 3.5) was proposed by Su et. al. This isolator is combination of good features of EDF and R-FBI systems. The upper surface of the R-FBI system is replaced with friction plates. As a result the structure can slide on its foundation in a manner similar to that of the EDF base isolator system. For a low level of seismic excitation, the system behaves as an R-FBI system. The sliding in the top plates occurs only during high level of ground acceleration, which provides additional safety against unexpected severe ground motion.

3.1.10. High damping rubber bearing

A blend of high damping rubber is used in these bearings (ref. Fig. 3.6). The compound, a high damping elastomer, is called KL301 and is manufactured by the Bridgestone Corporation Limited, Japan. KL301 has a shear modulus of about 4300 kPa at very small strains, which decreases to 650 kPa at 50% strain, to 430 kPa at 100% strain and 340 kPa at 150% strain. The typical bearing made of this rubber, consists of 20 layers of 2.2 mm thick rubber at 176 mm dia, nineteen 1mm steel shims, and 12 mm top and bottom plates. The design axial pressure is 3.23 MPa. The bearings were designed with flange type end plates to provide bolted structure and foundation connection.

Fig 3.5. Sliding resilient friction system

(a) Schematic diagram

b) Force deformation behavior

Fig 3.6. High damping rubber bearing

(a) Sectional details

(b) Forcedeformation behavior

(source:S.J.Patil, G.R.Reddy Website: www.ijetae.com)

3.1.11. Pure friction system

A pure friction type base isolator consists of developing frictional force by providing a sand layer or rollers at the base, which will dissipate the energy of earthquake force. The system is developed in China for low-rise structures. The system is useful for wide range of frequency input.

The main advantage of this isolation device is that it is very cheap. The main problem with the system is that it is unable to recover the displacement after earthquakes and sand layer is very sensitive for foundation settlement.

3.1.12. Friction pendulum system

Friction pendulum system (ref. Fig. 3.7) uses geometry and gravity to achieve the desired seismic isolation. It is based on well-known engineering principles of pendulum motion. The structure supported by the FPS responds to the earthquake motions with small pendulum motions. The friction damping absorbs the earthquake energy. There are variety of friction pendulum system developed by various researchers such as, variable frequency pendulum isolators by Pranesh & Sinha, 2000, variable curvature pendulum systems by Tsai et al, 2003, sliding concave foundation by Hamidi et al., 2003, double concave friction pendulum system by Fenz and Constantinou, 2006, Triple friction pendulum bearing, Fenz and Constantinou, 2008. Friction pendulum system is very efficient and cost effective seismic protection device, which simply alter the force response characteristics of the structure at base isolation level.

Fig 3.7. Friction Pendulum Base Isolator

(a) Friction pendulum system

(b) Roller pendulum system

(Source: S. J. Patil, G. R. Reddy Website: www.ijetae.com)

3.1.13. Spring type systems

Elastomeric and sliding isolation systems are effective in isolating the structure from horizontal forces. When three dimensional isolation is required, spring type systems have been used. The spring type system under the brand name of GERB was developed with large helical steel springs having flexibility both in horizontal and vertical direction. The vertical frequency of the system was 3 - 5 times the horizontal frequency. The steel springs were used with GERB visco damper.

The system has been used in two steel framed houses in Santa Monica, California. These houses were strongly affected by the 1994 Northridge earthquake. The response of these buildings was monitored and it was not effective in reducing the accelerations in these buildings due to rocking motion.

3.1.14. Sleeved pile isolation system

Where foundation soil is very soft up to large depths and provision of pile foundation is necessary, sleeved pile isolation system is useful from earthquake considerations. The system consists of providing a casing around the pile and a gap is maintained between the pile and the casing to accommodate the sway of the pile under earthquake load. The pile is passed through the soft soil and is supported and anchored in the rock below.

This system was implemented in the Union house in Auckland, New Zealand in the year 1983. The building is 12 storeyed tall and is supported on piles through soft soil for depth of 10m enclosed in steel casing. The period of the building on the sleeved pile system is 4 seconds.

3.1.15. Rocking systems

Tall slender structures, having heavy mass at the top, will invariably develop overturning moments which will lead to development of tensions in the foundations. It is extremely difficult to provide tension capacity in the foundations when foundations are in weak soil and providing anchors is a costly affair. As a remedy to this problem, it is possible to allow lifting of columns or piers from the foundation. This type of partial isolation will reduce the earthquake loads throughout the structure.

This concept was implemented in a railway bridge on south Rangitikei river in New Zealand in the year 1972. It has 69m long pier, which has been designed to lift under the earthquake load. Two large energy dissipating devices that are based on the elastic-plastic torsion of mild steel bars have been provided inside each pier. The method is not used again probably due to complexities involved in analysis and design of the system.

3.1.16. Base isolation using Geo- Synthetic materials

M.K. Yegian and U. Kadakal have developed a technique of isolating the base of the structures using geo-synthetic material. They have used high strength, non woven geotextile placed over an ultra high molecular weight polyethelene (UHMWPE) liner. These two materials have a static friction co-efficient of 0.1 and a dynamic friction coefficient of 0.07. Thus a geo-synthetic material placed underneath a foundation of a structure and over a liner will allow the dissipation of earthquake energy in sliding friction. They suggested that the sliding friction between the two materials should be in the range of 0.05 to 0.15. The authors have suggested arrangements as shown in fig 9 except the energy dissipating devices.

3.1.17. BS cushion

In 1999 a new kind of base isolator called BS cushion was invented (Chinese Patent Number ZL99202381.5) in Hangzhou, China. It is Treated Asphalt-Fiber Seismic Base Isolation Cushion”. The advantage of this kind of isolator is its low cost and safety while its isolation effect is moderate.

The invention of BS cushion reminds laminated steel-plate rubber bearing. Fiber and treated asphalt in BS cushion play similar role as of steel-plate and rubber in laminated rubber bearing respectively. Before 2001 two 7-storey masonry-concrete residential buildings isolated with BS cushion were built in Hangzhou, China. One is isolated by replacing some depth of base soil under mattress foundation with alternative setting of 4 layers of BS cushion and 4 layers of sand. The fundamental period of this building is elongated from 0.3 second to 1 second (0.3s is tested from a similar building and 1s is tested from this building).

3.2. Hybrid isolation system with semi-active devices

Hybrid isolation system uses both passive isolation systems and semi-active / active controlling devices. The Medical Centre of the Italian Navy at Ancona, Italy, was selected with the aim of analyzing the behavior of a hybrid system composed by Low Damping Rubber Bearings (LDRBs) acting as passive seismic isolators, and Magneto-rheological (MR) dampers, acting as semi-active controlling devices. The analyses showed that significant reduction of the building accelerations (up to 50%) can be achieved with the hybrid system.

3.3. Hybrid base isolation with passive energy dissipaters

` The energy dissipating devices (ref. Fig. 9 to 16) mainly dissipate the earthquake energy and thereby reduce the effect of the earthquake on the structure. These devices can be used at the base of the structure or in superstructure at appropriate locations. They can be used in combination with passive base isolation techniques. The different devices developed world over are shown in Fig. 3.8 to 3.13.

Fig. 3.8. Use of energy dissipating devices at base level

(Source: S. J.Patil, G. R. Reddy Website: www.ijetae.com)

Structure responses can be controlled by using Visco- Elastic dampers (VEDs), which are made of linear springs and dash pots provided in parallel and are generally used in bracings of building frame or at ground level.

Fig.3.9.Visco - Elastic Damper

(Source: S. J.Patil, G. R. Reddy Website: www.ijetae.com)

Elasto-Plastic Dampers (EPDs) are made of number of small ‘X’ shaped plates, which yield at small deformation thereby dissipate high amount of energy.

Fig. 3.10.Elasto-plastic damper

(Source: S. J. Patil, G. R. Reddy Website: www.ijetae.com)

Lead Extrusion dampers (LEDs) work on the principle of extrusion of lead. It absorbs vibration energy by plastic deformation of the lead, during which mechanical energy is converted into heat, lead gets heated up and on being extruded, lead re-crystallizes immediately and recovers its original mechanical properties before next extrusion

Fig. 3.11. Lead Extrusion damper

(Source: S. J. Patil, G. R. Reddy Website: www.ijetae.com)

Tuned Liquid dampers (TLDs) are rigid wall containers filled up to required height with a liquid (generally water) to match the sloshing frequency of the liquid with that of the structure. These containers are generally placed on the top of the structure. The vibration energy is dissipated in the sloshing action of the liquid.

Fig.3.12. Tuned liquid damper

(Source: S. J. Patil, G. R. Reddy Website: www.ijetae.com)

Shape Memory Alloy Dampers (SMADs) made of nickel-titanium (Ni-Ti) alloy wires has an interesting pseudo-elastic property by which the alloy regains its initial shape when external load is removed. This property is useful in putting back the structure to its original shape. Also it can sustain large amount of inelastic deformation.

Fig. 3.13. SMA damper

(Source: S. J. Patil, G. R. Reddy Website: www.ijetae.com)

An un-bonded brace, a technique developed in Japan, consists of developing a brace which is prevented from buckling by way of providing a metal collar filled with concrete at the center of brace and a thin layer of viscous material which allows slip and Poisson’s ratio expansion at the slip surface provide relative movement between the steel collar and surrounding concrete. This protects the brace from buckling and allows proper dissipation of energy in the brace through stable hysteresis loop. A buckling restrained or core loaded or non-buckling brace developed in IIT, Madras also works on the similar lines and dissipates the earthquake energy.

Tuned Mass Damper (TMD) is a spring – mass damper device generally connected to the structure at its top. It has been used as a passive control device for response reduction of tall buildings.

Examples Of Isolated Structures In Different Countries –

Few examples of isolated structures are William Clayton building, New Zealand, Medical Centre of the Italian Navy (Sarvesh K. Jain And Shashi K. Thakkar, 2004, LRB+MRD system), Nam-Han River bridge on the Young-dong expressway Seoul, Korea (Sun Young Lee, et al., 2004, LDRB+MRD system), Experimental building at IIT, Guwahati, India [8] etc.

The number of seismically isolated buildings in Japan, Russia, China, USA, Italy, Armenia, New Zealand were 1600, 500, 458, 100, 27, 14 and 11 respectively up to December 2002, 2003 and every year the number of isolated structures are increasing.

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By Anand Babu
Page 1 Next

ABSTRACT

The naturally occurring ground movement which eventually goes on creating disasters such as failure of structure and fatality is known as Earthquake. Nowadays a seismic event may also endanger the social-economical stability of large areas due to the complexity of technologically advanced constructions.

Base Isolation is a very effective way to destroy the damaging component of seismic forces and is one of the most widely implemented and accepted Design considerations for base isolated structures. The main objective of seismic isolation is to shift the fundamental frequency of a structure away from the dominant frequencies of the ground motions. Building is isolated from the ground such that earthquake motions are not transmitted up through the building. It is the main idea behind Base Isolation.

Seismic isolation is done by supporting the structure on laminated rubber bearings, friction pendulum bearings, roller bearings etc. Rarely soil is also used as a base Isolation media. This paper describes the base isolation techniques and other techniques developed to resist earthquake forces on the structures.

It has become evident in recent times that base isolation can be very effective in the event of an earthquake. So a case study of recent time describing the use of Base isolators during the reconstruction of District hospital of Bhuj, Gujarat, which had destroyed due to an earthquake is also included in this paper.

CHAPTER 1

INTRODUCTION

The naturally occurring ground movement which eventually goes on creating disasters such as failure of structure and fatality is known as Earthquake. The energy that is discharged from those seismic activities makes waves, these waves are called as primary waves and secondary waves.These waves cause ground movement transmitted to the structure via foundation. Depending on the intensity of these vibrations, cracks and settlement is caused to the structure.Inertia force is induced in structure because of this earthquake movement. The maximum point at which the structure can deform and come back to its original shape is called as Elastic limit. If building deforms more than its elastic limit, it forms cracks in the structure. However, ductility will induce some acceptable damage to the structure. If more elasticity is introduced to the structure, it may tend to increase the overall cost and decrease the damage by increasing the strength.Earthquakes are unanticipated phenomena if the structure is located in seismic zones. The structural engineer has to step in so as to save lives and cause minimal damage to the structures in times of earthquake. The recent development for anti-seismic designs is base isolation. Base isolation system is the frequently adopted earthquake resistance system. It reduces the effect of ground motion and thus reduce the effect of earthquake on the structure.

The field of seismic design is a subject that deals primarily with life safety and uncertainty. For several years now, it has been a quest for structural engineers to design earthquake-proof buildings and bridges. Initially, it has been generally thought that building a massive and stiff construction would make it earthquake resistant. But this stiffness or rigidity of the structural elements would lead eventually to a fragile and sudden failure, all in all not complying with the life safety performance criteria and letting inhabitants no time to react in case of an earthquake.

Next, the increase of damping, redundancy of buildings, ductility and seismic energy dissipation were taken into consideration and well implemented throughout the years in seismic building codes. Furthermore, a new alternative approach was implemented in earthquake protective systems and base isolation being one of the most common systems nowadays.

CHAPTER 2

CONCEPT OF BASE ISOLATION

Base isolation has become a traditional concept for structural design of buildings and bridges in high risk areas. By introducing flexible isolation system between the foundation and the structure the system will absorb the shock impact effects of earthquake with the help of its flexibility. This way the seismic energy transmitted to the structure will be reduced to greater extent and the structure will remain stable for a relative period. Rubber bearing and lead rubber bearing are prime factors used to introduce flexibility in the structure. This increased the natural period of the structure and base displacement is more than prearranged limit. Though, base isolation not always liable to work against the strong earthquakes as it may result in larger displacement at the base of the structure. Figure 2.1 shows the performance of building with and without isolation

Fig.2.1. Performance of Building with & without Isolation (source:Dr. R. S. Talikoti, Mr.Vinod R. Thorat www.ijert.org)

Basic principle of base isolation is to differentiate the building from its foundation. During the seismic action, building is unaffected from the ground motion. In other words, even though ground moves aggressively, the building will tend to move ideally as a rigid body rather than collapsing. This reduces the floor hastening and storey gliding and so the building components are less harmed. Any stiff structure will have short period. During the ground movement, amount of acceleration entrusted in the structure is the same as that of ground acceleration that results in zero displacement between the structure and the ground. In other words, ground and structure will move with equal amount.

Base isolation increase the flexibility of the structure and hence increases the period of the structure which is due to the isolators. By introducing base isolation in a structure increases the displacement and eventually decreases the acceleration in the structure as the stiffness of the structure also decreases. Generally, the isolation is placed at the base of the structure, Base isolation protects the building components of the superstructure during earthquakes. So flexible structure will have longer life span.

The principle in base isolation,

• To provide horizontally flexible as well as vertically stiff to the building.

• To lengthening the natural period of the building.

• Damping in the Isolation system reduces the displacement.

• It also reduces in the acceleration of the story.

Base isolation system should contain following:-

• An elastic mount to add enough vibration periods to the structure to lower down the forces in the structure over.

• An energy dissipater or damper to ease the deflection taking place between the structure and the ground.

• Introducing the stiffness against the seismic actions and wind loads.

Base Isolation Consideration

Base isolation is required if any circumstances arise of the

following:-

• Need to increase the safety of the structure.

• Low lateral seismic forces needed.

• Any existing building is not capable to withstand any earthquake.

• Withstand small earthquakes without any damage.

• Structure will not collapse in high level earthquake but some structural and non-structural damage will occur

PAGE

LIST OF SEMINARS

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ENVIRONMENTAL ENGINEERING M.TECH SEMINAR

TRANSPARENT CONCRETE

2016-06-22T10:02:00.001-07:00

1. INTRODUCTION

Concrete has been used since Roman times for the development of infrastructure and housing, but its basic components have remained the same. Three ingredients make up the dry mix: coarse aggregate, consisting of larger pieces of material like stones or gravel; fine aggregate, made up of smaller particles such as sand; and cement, a very fine powder material that binds the mix together when water is added.

Just a few decades ago concrete was often misunderstood, disliked and captured by its image fixed due to the rapid urbanization of the 1960s. But since that time, concrete has made considerable progress, not only in technical terms, but also in aesthetic terms.

It is no longer the heavy, cold and grey material of the past; it has become beautiful and lively. By research and innovation, newly developed concrete has been created which is more resistant, lighter, white or colored, etc. Concrete has learned to adapt to almost all new challenges that appeared. In 2001, the concept of transparent concrete was first put forward by Hungarian architect Aron Losonzi at the Technical University of Budapest, and the first transparent concrete block was successfully produced by mixing large amount of glass fiber into concrete in 2003, named as LiTraCon. The transparent concrete mainly focuses on transparency and its objective of application pertains to green technology and artistic finish. It is the “combination of optical fibers and fine concrete”. At present, green structures focus greatly on saving energy with indoor thermal systems. Therefore it is imperative to develop a new functional material to satisfy the structure in terms of safety monitoring (such as damage detection, fire warning), environmental protection and energy saving and artistic modeling.

Due to globalization and construction of high-rise building, the space between buildings is reduced; this causes to increasing the use of non- renewable energy sources, so therefore there is a need of smart construction technique like green building and indoor thermal system.

Translucent concrete (Transparent concrete) is new technique different from normal concrete. Translucent concrete allow more light and less weight compared to normal concrete. The use of sunlight source of light instead of using electrical energy is main purpose of translucent concrete, so as to reduce the load on non- renewable sources and result it into the energy saving. Optical fibers is a sensing or transmission element, so decrease the use of artificial light, the normal concrete is replaced by translucent concrete, which has natural lighting and art design.

Table 1. Properties of Transparent Concrete Blocks By Litracon Company

2. INGRIEDIENTS OF TRANSPARENT CONCRETE

· Cement

Cement is a binder, a substance that sets and hardens as the cement dries and also reacts with carbon dioxide in the air dependently, and can bind other materials together. Portland cement is the most common type of cement in general use around the world, used as a basic ingredient of concrete, mortar, stucco, and most nonspecialty grout. The OPC was classified into three grades namely, 33 grade, 43 grade and 53 grade depending upon the strength of the cement at 28 days when tested as per IS 4031-1988. The cement used in this experimental works is “Koromandal King 53 Grade Ordinary Portland Cement”. The specific gravity of cement was 3.14. The initial and final setting times were found as 51 minutes and 546 minutes respectively. Standard consistency of cement was 40%.

· Fine aggregate:

Fine aggregate is the inert or chemically inactive material, most of which passes through a 4.75 mm IS sieve and contains not more than 5 per cent coarser material. The specific gravity 2.75 and fineness modulus of 2.80 were used as fine aggregate. The loose and compacted bulk Density values of sand are1600 and 1688 kg/m3 respectively, the water absorption of 1.1%.

The fine aggregates serve the purpose of filling all the open spaces in between the coarse particles. Thus, it reduces the porosity of the final mass and considerably increases its strength. Usually, natural river sand is used as a fine aggregate. However, at places, where natural sand is not available economically, finely crushed stone may be used as a fine aggregate.

· Coarse aggregate:

Crush granite aggregate available from local sources has been used. The coarse aggregate with maximum size of 10mm having the specific gravity value of 2.6 and fineness modulus of 5.60 were used as a coarse aggregate. The loose and compacted bulk density values of coarse aggregate are 1437 and 1556 kg/m3 respectively, the water absorption of 0.4%.

· Optical Fibers Elements:

Core - The thin glass center of the fiber where the light travels is called core.
Cladding - The outer optical material surrounding the core that reflects the light back into the core. To confine the reflection in the core, the refractive index of the core must be greater than that of the cladding.
Buffer Coating – This is the Plastic coating that protects the fiber from damage and moisture.

Fig 2.1 Elements of a optical fibre

· Water: Water should be free from acids, oils, alkalies vegetables or other organic impurities. Soft waters also produce weaker concrete. Water has two functions in a concrete mix. Firstly, it reacts chemically with the cement to form the cement paste in which the inert aggregates are held in suspension until the cement paste has hardened. Secondly, it serves as a lubricant in the mixture of fine aggregates and cement

3. OPTICAL FIBERS

Optical fiber is a wave guide, made of transparent dielectric (glass or plastics) in cylindrical form through which light is transmitted by total internal reflection. It guides light waves to travel over long distances without much loss of energy. Optical fiber consists of an inner cylinder made of glass or plastic called core of very high refractive index. The core is surrounded by a cylindrical shell of glass or plastic of lower refractive index called cladding. The cladding is covered by a jacket which protects the fiber from moisture and abrasion.

3.1. Types of Optical Fibers

Based on the refractive index profile and the number of modes, optical fibers are divided into three types. They are:

Ø Step index single mode fiber
Ø Step index multimode fiber
Ø Graded index multimode fiber

A step index single mode fiber may have very small core diameter (i.e. 5- 10µm). Due to its small core diameter, only a single mode of light ray transmission is possible. About 80% of the fibers that are manufactured in the world today are of this type.

Fig 3.1 Step index single mode fiber

A step index multimode fiber has a core diameter of 50 to 200µm and an external diameter of cladding 125 to 300µm. Since the core material is of uniform refractive index and the cladding material of lesser refractive index than that of core, there is a sudden increase in the value of refractive index from cladding to core. Since the core has larger diameter, propagation of many modes within the fiber is allowed.

Fig 3.2 Step index multimode fiber

In a graded index multimode fiber, the refractive index of the core is maximum at the axis of the fiber and it gradually decreases towards the cladding. Since there is a gradual decrease in the refractive index of the core the modal dispersion can be minimized.

Fig 3.3 Graded index multimode fibre

3.2. Total Internal Reflection In A Fiber

The principle behind the transmission of light waves in an optical fiber is total internal reflection. The total internal reflection in the walls of the fiber can occur only by the following two conditions:

i. The glass around the centre of the fiber (core) should have higher refractive index (n1) than that of the material (cladding) surrounding the fiber (n2).

ii. The light should incident at an angle (between the path of the ray and normal to the fiber wall) greater than the critical angle, θ_c.

Fig 3.4 Total internal reflection

4. MANUFACTURING OF TRANSPARENT CONCRETE

Preparation of mould: In the process of making light transmitting concrete, the first step involved is preparation of mould. The mould required for the prototype can be made with different materials which can be of either tin or wood. In the mould preparation, it is important to fix the basic dimensions of mould. The standard minimum size of the cube according to IS 456-2000 is 15cmx15cmx15cm for concrete. In the mould, markings are made exactly according to the size of the cube so that the perforated plates can be used. Plates made of sheets which are used in electrical switch boards is used which will be helpful in making perforations and give a smooth texture to the mould, holes are drilled in to the plates as shown in Fig. 4.1 The diameter of the holes and number of holes mainly depends on percentage of fiber used.

Fig. 4.1 Preparation of mould

Procedure of making translucent panel:

Step 1-Preparation of the Mould:

A mould of rectangular cross section of size 150mm*150mm*150mm is made with wood or steel. Make the required size of rectangular mould from wood or tin. Place the clay or mud in the sides where the optical fibers are exposed to the mould for the easy demoulding after the concreting.

Fig. 4.2 Preparation of panel.

Step 2- Optical Fiber:

The optical fibers are cut carefully to the required size of mould. The commonly available diameters of optical fibers are .25 mm, .5 mm, .75 mm, 1 mm, and 2 mm.

Fig.4.3 Optical Fibers

Step 3- Fixing the Fibers:

Fibers are placed either in organic distribution or in layered distribution. Holes are driven on the wooden or steel plates through which optical fibers are allowed to pass through.

Fig. 4.4 Fixing of fibers.

Step 4- Concreting:

The thoroughly mixed concrete is poured carefully and slowly without causing much disturbances to the previously laid optical fibers. The concrete is filled in smaller or thinner layers and is agitated with the help of vibrating tables to avoid the void formation.

Mix proportion:

In present work Indian standard method (IS 10262-2009) is used for mix design, mix proportion are as table 4.1.

Table 4.1 Mix proportion used for testing

Step 5- Removing the Mould:

After 24 hrs, remove the mould and pull off the mud. The casted mould was kept undisturbed on the leveled platform. Then it was de-moulded carefully after 24 hours from casting. Immediately after de-moulding, the cube specimens were marked by their respective identification mark/numbers (ID).

Step 6- Cutting and polishing:

Cut the extra-long fibers same as thickness of panel. Polish the panel surface by using polishing paper or using sand paper as shown in figure 4.5

Fig 4.5 Trimming and polishing of the surface

5. TESTS CONDUCTED ON TRANSPARENT CONCRETE

Several experiments were conducted on transparent concrete tostudy about its various properties. They are as follows:

5.1. EVALUATION METHOD OF LIGHT GUIDING OF SMART TRANSPARENT CONCRETE

The following are the factors to be considered for the performance of the transparency of the concrete:

(A)Transmittance (B)Haze (C)Bi-fringence (D)Refractive index. (E)Dispersion

The transmittance can be directly calculated by the ratio of the incident energy and transmission energy of light expressed as following equation:

.....(1)

where ρ, ξ, J1 and J2 are transmittance, correction coefficient of measurement equipment, transmission energy and incident energy, respectively. While the translucent concrete studied by us is heterogeneous, its transmittance cannot be obtained by equation (1), because the number of POFs in unit area is different at different area, that is, the transmittance in unit is related to the arrangement of POF in translucent concrete. The POFs can be arranged either in organic distribution or in layered distribution.

Improvement in the calculation method for transmittance is as follows.
a) Incident light energy per unit area (ρ0):

........(2)

where W0 and A0 are light energy of incident probe and area of incident probe

b) Incident total energy of concrete section at the side of light (J_S^O ):

.......(3)

where A1 is the cross-section area of translucent concrete.

c) Transmitted light energy of single POF (ρ1):

.........(4)

where W1 and n1 are light energy of transmission probe and the number of POFs covered by transmission probe.

d) Transmitted light energy of translucent concrete (J_S¹):

.........(5)

where N is the total number of POFs in the translucent concrete.

Then based on equation (3) and (5), we can obtain the transmittance (ρ^s) of the translucent concrete.

5.2. LIGHT GUIDING EXPERIMENT OF TRASPARENT CONCRETE

In order to study the light guiding property of translucent concrete, six units of translucent concrete is fabricated with different POF volume ratios of 1%, 2%, 3%, 4%, 5% and 6%, and the diameters of POF is 1mm. The transmittance is measured by the Optical Power Meter and its wavelength range is 400-1100nm. The incandescent lamp with 200W and halogen lamp with 500W are chosen to provide light. To eliminate the measuring dispersion of transmittance caused by the discrepancy of POFs’ position and the material, three areas (denoted as 1, 2 and 3) in the middle part of translucent concrete are chosen to test shown as figure below, and the number of POFs in each chosen area shall be equal. The number of the POFs is covered by transmission probe or integral sphere are 2 for 1% POF volume ratio, 4 for 2% POF volume ratio, 5 for 3% POF volume ratio, 7 for 4% POF volume ratio, 3 for 5% POF volume ratio and 9 for 6% POF volume ratio respectively. The incident light energy and transmission light energy are read simultaneously at each step.

Fig: 5.1 Optical Power Meter Fig:5.2 Measuring area of the optical fibers

5.3. COMPRESSIVE STRENGTH

By definition, the compressive strength of a material is that value of uniaxial compressive stress reached when the material fails completely. The compressive strength is usually obtained experimentally by means of a compressive test. The compressive strength of the concrete is determined by cast the cubes of size 150mm x150mm x 150mm.

Compressive strength = load / area (6)

5.4. FLEXURAL STRENGTH

The flexural strength of the concrete is determined by conducting the test on prism by two point loading.

Flexural strength = PL/bd2 (7)

where, P – Load, L – Length of the specimen, b - width of the prism, d – depth of the prism

5.5. TEST OF MECHANICAL PROPERTY OF TRANSLUCENT CONCRETE BY FREEZING TEST

In this test, the POF volume ratios of translucent concretes chosen for test are 0% (or plain concrete), 1%, 2%, 3%, 4%, 5% and 6%. After 25 freeze-thaw cycle test, the mechanical properties of translucent concrete are evaluated by the compressive strength loss rate (Pf), expressed as follows.

.....(8)

where f_c₀ and f_cn are compressive strength before and after freeze-thawing test.

Fig 5.1 Methodology of freezing- thaw test

6. RESULTS AND DISCUSSIONS

6.1. LIGHT GUIDING PROPERTY:

(Source: SOUMYAJIT PAUL, AVIK DUTTA Transparent Concrete International Journal of Scientific and Research Publications, Volume 3, Issue 10, October 2013 1 ISSN 2250-3153)

Figure 6.1.1(a) and figure 6.1.1(b) show the light guiding property of translucent concrete with the POF volume ratio of 1%, 2%, 3%, 4%, 5% and 6% by using the halogen lamp and incandescent lamp, respectively. It can be seen that the transmittance of each type of translucent concrete almost keeps stable at whole wavelength, and the linear relationship between the POF volume ratio and its transmittance is good.

Fig 6.1.1 (a): Transmittance Fig 6.1.1(b): Relationship b/w POF volume and Transmittance

For the halogen lamp, the transmittances of the six ratio translucent concrete are 0.29%、 0.59%、 0.98%、 1.41%、 1.83% and 2.36%; for the incandescent lamp, the corresponding transmittances are 0.41%、 0.82%、 1.22%、 1.72%、 2.15% and 2.59%, respectively. The discrepancy of transmittance induced by different lamp is that the light scattering’s angle of the chosen lamp is different, and the POFs absorb much light scattered by incandescent lamp than that by halogen lamp.

Fig 6.1.2 (a): Transmittance Fig 6.1.2(b): Relationship b/w POF volume and Transmittance

Furthermore, it is worthily of note that the large the POF volume ratio is, the large the transmittance is. In fact, the POF volume ratio and the corresponding transmittance are just like a sword with both edges. We cannot only pay attention to the high transmittance, for the POF inevitable affects the concrete strength. In the following experimental results, it can be seen that POF will reduce the concrete strength.

6.2. MECHANICAL PROPERTY OF TRANSLUCENT CONCRETE AT FREEZE-THAW

From figure 6.2.1, it can be seen that the mass of translucent concretes almost are unchanged in 25times freezing and thawing cycle and the maximum loss rate of mass is about 0.4%. Figure 6.2.2 shows the compressive strengthen of translucent concretes with freeze-thaw or not. It can be seen that the compressive strength of each type of translucent concrete have greatly decreased after 25times freeze-thaw cycle, and the maximum loss rate of compressive strength is about 42% comparison with that without bearing the function of freeze-thaw for the same type of concrete. It can be seen that the larger the POF volume ratio is, the smaller the compressive strengthen of the translucent concrete is. So we cannot endless increase the transmittance by way of increasing the POF volume ratio. One point to be mention, the compressive strengthen of the plain concrete (or the translucent concrete with 0% POF volume ratio) is smaller than that of the accustomed plain concrete. The reason is that we consider the fabrication method of the translucent concrete and ignore the normal mix proportion of cement mortar at pre-test. To improve the compressive strength of the translucent concrete, one solution is that the translucent concrete can be produced by some special high strength concrete, which can reduce the impact of the POF to the concrete’s compressive strength.

Fig 6.2.1: Loss rate of concrete mass at each freeze thawing

Fig 6.2.2: Compressive strength of concrete block with freeze-thaw

6.3. COMPRESIVE STRENGTH

The compressive strength for concrete cubes with and without Optical fibers has been calculated for3, 7and 28 days. From the test results, it is observed that compressive strength for 3, 7 and 28 day with Optical fibers is 8.82 N/mm2,11.45 N/mm2 and 21.10N/mm2 respectively. That for Conventional concrete is 9.56 N/2, 13.02 N/mm2 and 23.24 N/mm2 respectively.

6.4. FLEXURE STRENGTH

The flexural strength of the conventional concrete and light transmitting concrete in 7, 14 and 28 days is shown in Fig 6.4.1

Fig 6.4.1 Flexural strength of concrete

7. APPLICATIONS

A. Illuminate Your Walls

Transparent Concrete can be used as building material for interior and exterior walls. If sunshine illuminates the wall structure, then eastern or western placement is recommended; the rays of the rising or setting sun will hit the optical glass fibers in a lower angle and the intensity of the light will be bigger. Besides the traditional applications of a wall, the light transmitting concrete can also be used as wall covering illuminated from the back.

Fig 7.1 Translucent Wall for Architectural View

(Source: www.litracon.hu)

B. Pavement Shine at Sunset

This concrete can be used as flooring a passable surface illuminated from below. During the day it looks like typical concrete pavement but at sunset the paving blocks begin to shine and in different colors.

C. Creative Design

The building units are versatile and can be used in many areas of design. Two successful designs using the light transmitting concrete were a jewel and a concrete bench. You can also create a logo with colorful figures, inscriptions, and pictures and can used for beautification purpose.

D. Artsy Reception Desk

If you really want to create a look that stands out, you should opt for this artsy and vogue reception desk where light up in the front and the sides.

E. A Lighting fixture and Conversational Piece

The transparent concrete cube is, without a doubt, a great conversation piece. The new cube line consists of four identical pieces of concrete and, due to its special geometry; the pieces form a stable structure without fixing them together.

It can be also applicable at:

· Transparent concrete blocks suitable for floors, pavements and load-bearing walls.
· Facades, interior wall cladding and dividing walls based on thin panels.
· Partitions wall and it can be used where the sunlight does not reach properly.
· In furniture for the decorative and aesthetic purpose.
· Light fixtures.
· Light sidewalks at night.
· Increasing visibility in dark subway stations
· Lighting indoor fire escapes in the event of a power failure.
· Illuminating speed bumps on roadways at night.

8. A CASE STUDY ON TRANSPARENT CONCRETE

Transparent concrete is a pretty rare sight. Not many people have a particular idea about this nor its applications and advantages. The largest project exhibiting this technology is an artistic installation, called the "European Gate"(2004) which was designed to mark the celebration of Hungary joining the European Union (EU). Located at the public entrance of Fortress Monostor in the Hungarian town of Komarom, this is one of the most impressive pieces of art conjugating visual lighting display as well as artistic using translucent concrete. The sun illuminates the 37.6 ft² large Litracon piece of the statue in the mornings and late afternoons, and by night an even more impressive view can be seen because of the embedded light sources. One of the first projects to be ever made in a major way is this road during the day the blocks appear as concrete pavement, but at sunset they start to shine thanks to the light sources placed under then. A ringed light pattern took shape around the main square as dark came. More of the uses or applications include partitions or partition walls in office cabins or in houses, and attractive furniture, and intelligent light fixtures, lighting in dark subway stations.

The Italian pavilion at the Shanghai World Expo 2010 also uses the light transmitting concrete in the building. The transparent blocks of concrete were interspersed with opaque blocks to create a seamless façade that allows diffused light in at certain areas and emanates a glow at night.

There aren't many manufacturers of translucent concrete. There are very few of them, namely LitraCon, Lucon and Lucem Lichbeton. By using fibers of different diameters, Litracon™ designers can achieve different illumination effects. An article in the New York Times suggested that the concrete would be very expensive because of its optic fiber content, so the uses were very small in size but quite amazing to the eye. Some examples of the product are the following: On the performance side, it's simply a concrete embedded with optical fibers running in a matrix while still retaining the strength of concrete. Therefore it still retains the high density top layer. It is also frost and de-icing salt resistant, making it highly recommendable in cold countries. Similarly, it is under fire protection classification A2 and provides very high UV resistance.

Fig 8.1 Transparent concrete on Italian Pavilion

9. ADVANTAGES

· The main advantage of these products is that on large scale objects the texture is still visible - while the texture of finer translucent concrete becomes indistinct at distance.
· When a solid wall is imbued with the ability to transmit light, it means that a home can use fewer lights in their house during daylight hours.
· It has very good architectural properties for giving good aesthetical view to the building.
· Where light is not able to come properly at that place transparent concrete can be used.
· Energy saving can be done by utilization of transparent concrete in building.
· Totally environment friendly because of its light transmitting characteristics, so energy consumption can be reduced.

10. DISADVANTAGES

· The main disadvantage is these concrete is very costly because of the optical fibers.
· Casting of transparent concrete block is difficult for the labour so special skilled person is required.

11. CONCLUSION

A novel architectural material called transparent concrete can be developed by adding optical fiber or large diameter glass fiber in the concrete mixture. The transparent concrete has good light guiding property and the ratio of optical fiber volume to concrete is proportional to transmission. The transparent concrete does not loose the strength parameter when compared to regular concrete and also it has very vital property for the aesthetical point of view. It can be used for the best architectural appearance of the building. It can also be used in areas, where the natural light cannot reach with appropriate intensity. This new kind of building material can integrate the concept of green energy saving with the usage selfsensing properties of functional materials.

12. REFERENCE

1. Soumyajit Paul And Avik Dutta, Translucent Concrete, International
Journal of Scientific and Research Publications, Volume 3, Issue 10, October 2013 1 ISSN 2250-3153

2. P. M. Shanmugavadivu, V. Scinduja, T. Sarathivelan, C.V
Shudesamithronn, An Experimental Study On Light Transmitting Concrete, International Journal of Research in Engineering and
Technology eISSN: 2319-1163 | pISSN: 2321-7308

3. Zhi Zhou, Ge Ou, Ying Hang, Genda Chen, Jinping Ou, Research and Development of Plastic Optical Fiber Based Smart Transparent Concrete, Proc. of SPIE Vol. 7293 72930F-2

4. Andrea Giovanni Mainini, Tiziana Poli, Michele Zinzi, Stefano
Cangiano, Spectral light transmission measure and radiance model validation of an innovative transparent concrete panel for façades, Elsevier
SciVerse ScienceDirect, Energy Procedia 30 ( 2012 ) 1184 – 1194

5. Basma F. Bashbash, Roaa M. Hajrus, Doaa F. Wafi, Mamoun A.
Alqedra, Basics of Light Transmitting Concrete, Global Advanced
Research Journal of Engineering, Technology and Innovation (ISSN: 2315-5124) Vol. 2(3) pp. 076-083, March, 2013

6. Neha R. Nagdive & Shekar D. Bhole, To evaluate properties of translucent concrete / Mortar & their panels, IMPACT: International
Journal of Research in Engineering & Technology (IMPACT: IJRET) ISSN(E): 2321-8843; ISSN(P): 2347-4599 Vol. 1, Issue 7, Dec 2013, 23- 30

7. Juan She and Zhi Zhou, Some Progress on Smart Transparent Concrete,
Pacific Science Review, vol. 15, no 1, 2013, pp. 51~55

8. Dr. Shakir Ahmed Salih, Dr. Hasan Hamodi Joni, Safaa Adnan
Mohamed, Effect of Plastic Optical Fiber on Some Properties of Translucent Concrete, Eng. &Tech. Journal,Vol.(32),Part(A), No.12,2014

9. Prof. A.A. Momin, Dr. R.B. Kadiranaikar, Mr.Vakeel. S. Jagirdar,
Mr. Arshad Ahemed Inamdar, Study on Light Transmittance of Concrete Using Optical Fibers and Glass Rods, IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE) e-ISSN: 2278-1684, pISSN: 2320-334X PP 67-72

10. Bhavin K. Kashiyani, Varsha Raina, Jayeshkumar Pitroda, Dr.Bhavnaben K. Shah, A Study on Transparent Concrete: A Novel Architectural Material to Explore Construction Sector, International Journal of Engineering and Innovative Technology (IJEIT), ISSN: 2277- 3754 Volume 2, Issue 8, February 2013

11. Ramansh Bajpai, Application Of Transparent Concrete In Construction World, i-manager’s Journal on Civil Engineering, Vol. 4 l No.1 l December 2013 - February 2014

12. A. B. Sawant, R. V. Jugdar, S. G. Sawant, Light Transmitting Concrete by Using Optical Fiber, International Journal of Inventive Engineering
and Sciences (IJIES) ISSN: 2319–9598, Volume-3 Issue-1, December 2014

13. Er. Jadhav Sunil, Er. Kadlag Amol, Er. Kawade Chetan, Er. Talekar
Pravin, A Study on Translucent Concrete Product and Its Properties by Using Optical Fibers, International Journal Of Modern Engineering
Research (IJMER) ISSN: 2249–6645 Vol. 5 Iss.4 Apr. 2015

14. Akshaya B Kamdi, Transparent Concrete As A Green Material For Building, International Journal Of Structural And Civil Engineering
Research ISSN 2319 – 6009 Vol. 2, No. 3, August 2013

SUBMERGED FLOATING TUNNEL

2016-06-22T09:40:00.003-07:00

1. INTRODUCTION

Tunnels in water are by no means new in civil engineering. Since about 1900, more than 100 immersed tunnels have been constructed. Bridges are the most common structures used for crossing water bodies. In some cases immersed tunnels also used which run beneath the sea or river bed. But when the bed is too rocky, too deep or too undulating, submerged floating tunnels are used.

The submerged floating tunnel, SFT, also named as Archimedes Bridge, is a concept going back at least 150 years and probably even further back. Historic records show that a rather complete understanding of this idea was brought forward by Sir James Reed, UK in 1886 and later in 1924 by Trygve Olsen Dale, Norway.

The Submerged Floating Tunnel concept was first conceived at the beginning of the century, but no actual project was undertaken until recently. As the needs of society for regional growth and the protection of the environment have assumed increased importance in this wider context, the submerged floating tunnel offers new opportunities. The submerged floating tunnel is an innovative concept for crossing waterways, utilizing the law of buoyancy to support the structure at a moderate and convenient depth .The Submerged floating Tunnel is a tube like structure made of Steel and Concrete utilizing the law of buoyancy. It is supported on columns or held in place by tethers attached to the sea floor or by pontoons floating on the surface. The Submerged floating tunnel utilizes lakes and waterways to carry traffic under water and on to the other side, where it can be conveniently linked to the rural network or to the underground infrastructure of modern cities.

2. SFT CONCEPT

The SFT is a new transportation concept for crossing straits, lakes or waterways in general. It is basically a tube like structure floating at some depth in the water, where the tube is large enough to accommodate road and/or rail traffic. As with any structure floating in water, it must be moored or fixed against excessive movements.

Fig. 2.1 A simple cross section of SFT

Fig. 2.2 A typical cross section of SFT

2.1 BASIC PRINCIPLE

SFT is a buoyant structure which moves in water. The relation between buoyancy and self weight is very important, since it controls the static behaviour of the tunnel and to some extent, also the response to dynamic forces. Minimum internal dimension often result in a near optimum design. There are two ways in which SFT can be floated. That is positive and negative buoyancy.

Ø Positive buoyancy: In this the SFT is fixed in position by anchoring either by means of tension legs to the bottom or by means of pontoons on the surface. Here SFT is mainly 30 metres below the water surface.

Ø Negative buoyancy: Here the foundations would be piers or columns to the sea or lake. This method is limited to 100 meters water depth.

SFT is subjected to all environmental actions typical in the water environment: wave, current, vibration of water level, earthquake, corrosion, ice and marine growth. It should be designed to with stand all actions, operational and accidental loads, with enough strength and stiffness. Transverse stiffness is provided by bottom anchoring. In principle, SFT can be considered for all waterway crossings, in practice they are of major interest especially where gentle gradients and low environment impact are important.

2.2 STRUCTURAL COMPONENTS

Submerged floating tunnel consists of many structural components. These components should provide strength and stiffness against the various forces acting under the water surface. The three basic structural components are:

· Tube
· Anchoring
· Shore connections

2.2.1 Tube

It should accommodate the traffic lanes and the equipments. External shape can be circular, elliptical or polygonal. It may be constructed of steel or concrete. Corrosion protection is the main issue. Tube is composed of elements of length varying from one hundred meters to half a kilometre.

2.2.2 Anchoring

There are basically four types of anchoring:

· SFT with pontoons
· SFT supported on columns
· SFT with tethers to the bottom
· SFT unanchored
· SFT with pontoons:

It is independent of water depth, the system is sensitive to wind, waves, currents and possible ships collision. Design should be such that if one pontoon is lost, then also the structure will survive

Fig. 2.3 SFT with pontoons

· SFT supported on columns:

It is an “underwater bridge” with foundations on the bottom, in principle the columns are in compression but they may also be a tension type alternative. Water depth will play an important role in this case and a few hundred meters depth is considered a limit at the present time. However, much deeper foundations are at present under investigation.

Fig. 2.4 SFT with columns

· SFT with tethers to the bottom:

It is based on tethers being in tension in all future situations, no slack in these tethers may be accepted in any future load cases. The present practical depths for this type of crossing may be several hundred meters, whether the tethers are vertical or a combination of vertical and inclined.

Fig. 2.5 SFT with tethers

· SFT unanchored:

It is interesting as it has no anchoring at all except at landfalls and is then independent of depth. There is obviously a limit to the length but only further development will answer this. Perhaps an alternative for light traffic should be designed, possibly a 100 or 200 meter long.

Fig. 2.6 SFT unsupported

2.2.3 Connections

The connections of the tube to the shore require appropriate interface elements to couple the flexible water tube with the much more rigid tunnel bored
6 in the ground. This joint should be able to restrain tube movements, without any unsustainable increase in stresses. On the other hand the joints must be water tight to be able to prevent entry of water. Additional care in shore connections is required, especially in seismic areas, due to the risk of submarine landslides.

2.3 PROPOSED PROJECTS

In recent years, as the development of offshore engineering makes available appropriate technology for actual SFT construction, interest in SFT has been growing, especially in Norway, Italy and Japan and a number of projects have been developed, up to quite an advanced state.

Probably the most advanced project is, presently that of the Hogsfjord crossing, carried out by the Norwegian Public Road Administration. The crossing is 1400 metres long, with 150 metres maximum water depth. The tunnel will be placed about 25 metres below the water surface and will be circular in shape with 9.5 m inner diameter, inorder to accommodate a two lane road.

A more difficult and demanding project has been developed for Messina Straits where severe environmental conditions occur, along with a high seismic risk. The crossing is about 3000m long with 350 m maximum depth. Due to high traffic loading, the connection requires a four lane road and two railway lines. The project is still far from the construction stage, to some extent, due to the very challenging problems arising from the extremely adverse environment.

Table 1: Proposed projects

3. DESIGN, CONSTRUCTION AND OPERATION

This chapter contains a brief overview of the main topics related to SFT design, construction, operation and maintenance.

3.1 SFT DESIGN OVERVIEW

The procedures for design of a SFT go through the following main steps:

· Site characterization and definition of operational targets
· Definition of design criteria and loading conditions
· Choice of overall dimension
· Static and dynamic analysis
· Structural safety analysis
· Environmental impact studies
· Detailed design
· Specification of construction and installation procedures
· Specification of operation procedures and maintenance

3.2 DESIGN ISSUES

For design of an SFT the following basic considerations should be taken into account:

· The cross-section must give sufficient space for traffic, evacuation, ventilation, ballast, inspection, maintenance and repair works.
· The alignment must be such that there is no interference with ship traffic passing above the tunnel.
· The joints should have no less strength or integrity than the tube between the joints
· The structure must have a ductile behaviour in the potential failure modes
· The anchoring system should be redundant
· The tunnel must not be unduly susceptible to local damage
· The structural details must be simple & designed to avoid undue stress concentrations
· The tunnel must behave in a satisfactory manner with regard to deformations, settlements and vibration
· The tunnel must have a satisfactory safety against fatigue
· The tunnel should be designed such that the water inflow rate is so limited that people have time to safe evacuation in case of massive water ingress
· Tether lengths must be adjustable to compensate for e.g. possible settlements
· It must be possible to repair or replace parts of the structure that are considered to have a shorter service life than the tunnel tube itself. Such parts can be tethers and other anchoring systems, bearings and moveable joints.

3.3 DESIGN CONSIDERATIONS

3.3.1 Site Characterization and Operational Targets

Since SFT design is strongly dependent on location, a careful characterization of the site and detailed definitions of the operational targets are required, prior to any design development. Operational targets are mainly related to the transportation needs to be satisfied by the connection. These are expressed in terms of traffic volume, and on this basis transportation design (rail, road, number of lanes, and type of traffic) of the connection is performed. Site characterization involves:

· Geographical characteristics of the area
· Geological and geotechnical investigation
· Characterization of the water environment.
· Characterisation of the seismic hazard.
· Investigation of all relevant features (ship traffic, marine operation)
· Data collection for environmental impact assessment.
· Detection of all other constraints to SFT design (land use, water uses).

3.3.2 Design Methods

Like every other structure, SFT must be designed on the basis of expected and possible combination of loading cases. The allowable design methods and general criteria are mainly determined by national codes. Today the design methods are often related to those used in the offshore industry, and are commonly based on the semi probabilistic limit state approach, using partial safety coefficients on both loads and strength of materials.

Limit States

The semi-probabilistic approach divides the design into the following design limit states:

SLS (Service Limit State):The SLS conditions are set to ensure that the structure meets practical criteria with regards to deflection , crack, widths , factor of safety, acceleration etc.

ULS (Ultimate Limit State): The ULS conditions are set to confirm that the structure has the necessary margin of strength to survive factored load and load combinations , with the factor being set to provide an acceptable risk of failure. The factor must be sufficient to ensure that the structure is capable of continuing to operate satisfactorily after an unfactored event. The accepted risk level differs among countries.

PLS (Progressive Collapse Limit State): the PLS conditions are designed to preserve human lives in the event of certain loads or load combinations at very low probability of occurrence. In this case even if the structure may be severly damaged , loss of lives is still not acceptable. These conditions are often defined at a probability level of approximately 10^-4 per annum.

FLS (Fatigue Limit State): The FLS is required to account for the fact that some materials lose strength due to repeated loading . By computing the accumulated damage in the material and consequently checking the computed life of the structure against the operational life, the sensitivity of certain components of structure can be established. The safety factor of 3 to 10 between computed life and required operational life is often adopted depending on the consequences of failure and the opportunities for repair of the components.

3.3.3 Loading Conditions

Ø Permanent Loads

The permanent loads acting on a SFT are the weight of the various structural and non-structural components, the water buoyancy and the hydrostatic pressure.

Ø Functional Loads

Functional loads are related to the development of the functions for which the SFT is designed for, therefore these loads are associated with the passage of cars, trucks, trains and/or pedestrians, according to the destination of use of the SFT.

Ø Hydrodynamic Loads

Hydrodynamic actions due to the water-structure interaction in presence of waves and currents often represent the most important and onerous environmental actions for a SFT.

1. Currents

Currents in waterways can be of the following types:

· Wind generated currents: water motion is originated by the energy transferred to the water by the wind blowing over the water surface.

· Tidal currents: horizontal water motion resulting from the rise and fall of the water level due to tides (a vertical motion).

2. Waves

· Water waves differ from currents because they are characterized by an oscillating motion of the water particles and can be of two types:

· Wind generated waves: surface waves occurring on the free surface of waterways, due to the wind blowing over a vast enough stretch of fluid surface.

· Internal waves: water particles are kept in motion by the force of gravity acting on small differences in density. A density difference can exist between two fluids or between different parts of the same fluid because of a difference in temperature, salinity, or concentration of suspended sediment.

Ø Earthquake

Strong ground motion occurring to seismic events propagate in the structure by means of the tunnel shore connections and of the SFT anchoring system. However some specific issues have to be considered in the design phase, such as, for instance, the configuration of the shore connections or the behaviour of shorter anchoring elements located close to the shores. More generally, it is necessary to assure that every structural component safely withstand extreme seismic events and that functional performances are met in case of more frequent earthquakes. One safe way of dealing with this challenge is to design the tube and its supports such that the lower fundamental Eigen periods are safely below the periods of these forces. This however may have a big cost penalty since it generally would require a relatively large number of anchoring points, either through tethers or as pontoons. If it had been possible to design reliable artificial damping systems that could limit the resonance phenomena to tolerable levels, the number of such anchoring points and then also the cost could probably be significantly reduced.

Ø Accidental

Loads Accidental actions mainly include:

· Collisions due to dropping objects, sinking ships or impacts with submarines.
· Flooding.
· Rockslides
· Fire.
· Leakage

3.3.4 Load Applications

The magnitudes of applied loads and the associated acceptable structural behavior are defined in terms of their probability of occurrence. For example if the structure has a design period of 2000 years, the following levels where adopted:

1. Return period equal to 50 years: Serviceability behavior of both the main structure and the secondary components without any damage or need for inspection after the event.

2. Return period equal to 400 years: Serviceability behavior of the main structure and local damage (plastic behavior) for the secondary components. Limited damage, if any must be reparable without any interruption in the use of tunnel.

3. Return period equal to 2000 years: This was defined as plastic behavior with the complete exploitation of ductility resources of all the structural components. This would be analysed today as PLS. Damage, but not collapse of the main structure is accepted. Damage and collapse are accepted in the secondary component.

3.4 CONSTRUCTION

The construction of an SFT includes two basic concepts namely, Construction in elements and Incremental launching.

3.4.1 Construction In Elements

The construction in element appears to be more usual in the ongoing projects. The construction procedures developed up to now, mainly refer to SFT placed at sea. SFT in internal water bodies, local conditions, as well as problems are likely to require installation with smaller vessels. SFT elements are constructed in a dock and then towed to the SFT site. Basically there is no constraint to the element length, especially if permanent prestressing is used, the element length is mainly controlled by the features of the construction facility.

At the site the elements are ballasted and lowered to the desired depth, where they are coupled with the elements already in place, by means of specially designed joints. At each joint location, a set of tethers is pre-installed and coupled in a horse shoe shaped support. The element is lowered under the support while temporarily pulling the support aside.

After the element has been fitted to the predetermined tether support system, it is de-ballasted, causing the load to transfer from installation barge to the tether system. During this process, the length of the tethers is adjusted at the support shoe to prevent unacceptable deflection of both tethers, the position of new element and the previous elements. The adjustments can be made by remote control or by diver ROV (Remotely Operated Vehicle) assistance.

Final connection between the tunnel and the tethers depends on the location of the connection, i.e., whether they are external orwithin special chambers added to the tunnel. It also depends on whether the preference is to connect the tethers first to the anchor points on the bed or to the elements before it is lowered.

Fig.3.1 Type of installation at site

3.4.2 Incremental Construction And Launching

As a construction alternative, incremental launching requires that the construction takes place at one of the abutments; this implies that conditions for a large construction facility exist at the site. The tube is constructed in consecutive sections on an inclined skidway in the abutment. After the construction of one section is completed, the tube is moved forward into the water, by one section length through the gate in the abutment. A temporary support system must be provide to keep under control the part of the tube already in water, until the opposite shore is reached and final supports can be installed.

Fig.3.2 Incremental Launching

A combination of these two outline construction methods has also been considered. In this case elements are constructed in a dock and then towed to a specially push-out facility, located at one of the abutments.

3.5 OPERATION AND MAINTANENCE

Operation conditions for SFT will not be known until the first structure of this type has been constructed. In fact all well developed projects include a very extensive monitoring of the tunnel behavior, in order to control SFT performance and to acquire valuable experience for future design. Parameters to be monitored include:

· Environmental parameters: current, wave, temperature, water density, etc;
· Structural parameters: stress, strain, static and dynamic response
· Material behavior: cracking, corrosion marine growth
· Parameters related to environmental impact (inside and outside the tunnel)

However a set of crucial issues, besides monitoring, related to operation and maintenance includes:

· Traffic control
· Corrosion protection
· Surveys and inspection
· Repair

Traffic control is aimed at ensuring that the crossing SFT fulfils the design assumptions, both in quality and quantity. While control of traffic flows, in order to avoid any traffic congestion in the SFT, can be easily achieved, with the same techniques applied for land based tunnel, more skill is required to prevent access to the SFT for such type of goods (explosives), that must be avoided for safety reasons.

One of the most uncertain issues to the long term behavior of SFT, compared to other civil engineering structures, is the performance of corrosion protection systems and related corrosion control inspections. Experience from ship and offshore structures can be applied, as starting point to define standards and procedures for surveys and inspection. Structural behavior in damaged condition is a crucial for SFT repair. SFT design has to consider that damage can occur, during its lifetime, both to the tube and to the anchoring systems.

3.6 SAFETY

Since the concept of an SFT is still innovative, acceptable risk levels may initially need to be higher than for comparable projects because new safety issues are raised. Safety requirements should therefore be quantified to determine acceptable risk levels compared with the expected benefits during the working life of an SFT.

SFT safety criteria may be viewed in two ways:

· As normal rail or road tunnel, emphasizing structural safety.
· As the comprehensive transportation system, emphasizing operational safety.

3.6.1 Critical Structural Components

In order to make a safety assessment those components of a tunnel that are critical to life safety or the environment in the event of collapse, need to be identified, i.e.:

· Tendons or tether system.
· Terminal structures.
· Connection system between tunnel modules.
· Anchorages and foundations.
· Outer and inner shells.

Critical design conditions should include:

a) Extreme design environmental conditions.

b) Operational accidental conditions.

c) Damaged conditions due to deterioration or collapse of some of the above mentioned primary components.

3.6.2 Ship Collision

All of the feasibility studies for SFTs must focus attention on the accidental loading caused by the collision of ship or a submarine. The safety of an SFT is based on avoiding collision with vessels large enough to damage the structure seriously, as has happened many times to various bridges. Collision of surface vessels can be easily avoided as the SFT can be positioned at virtually any deapth beneath the water surface.

In the cases where there is heavy surface traffic the probability of a sinking ship at that particular location, and subsequent consequences must be considered. The energy associated with the impact of a sinking object against the structure must be absorbed by local or global deformation. The magnitude of absorption will depends on the type of ship.

Another form of accidental loading, which is probably more frequent but less sensitive is the impact of fishing equipment. This type of impact can largely be avoided by adherence of marine regulations.

A traffic regulation system has to be provided for submarine traffic. If necessary measures must be taken to ensure that both the tunnel and its support system can be monitored by the submarine navigational equipment. A warning system may be used to ensure the safety of the traffic in the SFT itself.

4. COMPETITIVE FEATURES OF SFT AND BENEFITS

· Invisible

Crossing waterways, whether being from main land to islands in the sea or maybe more important crossing and inland lake, perhaps the one we are at now will in many cases meet protests both from tourist interests and also from the public in general. Lakes of special beauty or perhaps historical value should be preserved for the future, the crossing of such areas and lakes with SFT may make this possible. An illustration of this may be seen in fig.5.

· Length only from shore to shore

Fig.5 also illustrates that the actual SFT structure is only as long as the distance between the shores. If desired the SFT may be connected directly to tunnels and then be completely out of sight for any desired distance.

Fig. 4.1 SFT crossing may be invisible

· An alternative to ferry

If a crossing is very deep and wide, many of the traditional types of bridges, immersed or undersea tunnels may be both technically and economically prohibitive and if a fixed link is wanted an SFT may be the only alternative. Another feature with the SFT is the lower energy use for crossing, driving cars on a fixed link will normally use considerably less energy than ferry operations.

· Very Low Gradient

An SFT crossing may have a very gentle gradient or being nearly horizontal giving considerable savings in energy used by traffic. Crossings with undersea tunnels or bridges will frequently mean longer structures with consequently higher costs and this may offset the higher cost per meter for an alternative SFT.

· Access to underground service parking space at end

As SFT may continue in tunnels having crossed the waterway, it is possible to arrange parking places or service areas under ground and provide access to the surface by lifts directly into cities or recreational areas as the case may be. These possibilities may be one of big advantage in future, in fact for all types of tunnel.

Fig. 4.2 Parking and service areas

· Constructed away from densely populated areas

One very interesting feature with SFT is that the actual construction may be done away from the densely or highly populated areas, a feature also for immersed tunnel construction. After the sections of the tunnel are finished they may be towed to the actual site and there joined together and installed at the desired depth. In some instances the whole length of the SFT may be assembled at the construction site and the complete structure towed to the actual site and installed. This would ensure minimum disturbances to the local area and perhaps the whole operation may only take months instead of years.

· Easy removal at end of life

SFT is in most cases a floating structure as a whole and may therefore be towed away to some place where parts of the SFT may be reused.Some possibilities of reuse or recycling SFT. Sections of a tunnel may be used for many purposes, depending on its size and condition. One obvious possibility is for various types of storage facilities, whether in the sea or on dry land, a section of tunnel

· Minimize the traffic congestion
· No impact on the landscape and no interference to sea surface activities.
· Better control of air pollution by providing proper ventilation system.
· SFT cost per unit length is approximately constant, while, for bridges, it significantly increases with the span length.

5. AREAS FOR IMPROVING SFT COMPETITIVENESS

In an effort to establish the present status of SFT and suggest areas for strengthening the competitiveness a short discussion of some possibilities are presented.

· The basic SFT design should be presented in a simple and understandable way to everybody; the importance of clear and good drawings cannot be overemphasized, clear 3-D presentations may be more important than pages of text.

· There are quite a number of structures similar to SFT around the world; especially immersed tunnels have many similarities with SFT. A large part of immersed tunnel technology is used for SFT construction and one of the important centers for immersed and floating tunnels may be found in the International Tunneling and Underground Space Association, ITA. Working Group 11 is dealing with Immersed and Floating tunnels and this is a forum for people interested in SFT and new members are very welcome at the yearly meetings. The structures similar to SFT should be published in SFT literature and reports. This would inform the engineering community about the present experience with these structures and also be a valuable reference of the behaviour of these structures in practice.

· Some of the more complex technical elements and procedures should be explained, for instance the construction methods of the tunnel, towing procedures, installation, anchoring methods and so on. This would familiarize the public with this structure and make it more acceptable to be used for great benefit to both local and regional areas.

· The structure itself should be studied for technical simplification in all areas. The simpler and clearer the methods and procedures, the greater the probability for a good end result.

· The structure should be robust and have some reserve capacity in all important areas; refinery should come at a later stage when experience is gathered.

6. CHALLENGES TO BE FACED

Because submerged in the water, SFT as a new type of structure, is confronting with different public safety risks during its construction and operation compared with common bridges. SFT is also facing many challenges because there is still no mature specification or criterion for the relevant design and construction technology of SFT. Therefore, systematical risk analysis and assessment are needed according to local environment and structural characters.

The natural hazard risks of SFT are as follows:

· Typhoon: The water waves caused by the typhoon make just tiny effects on SFT because SFT is usually placed at 10m or more than 10m under water surface, and the wave force is decreasing exponentially with depth. Although typhoon action on SFT structure is tiny, we should also consider secondary disasters caused by typhoon, such as landslide and slope failure.

· Earthquake: The main effect of earthquake to SFT includes forced
vibrations caused by subsoil’s vertical and horizontal shake. These may lead to local damages in SFT such as foundation damage and anchor cable failure, which can threaten the whole SFT structure in its underwater environment. So earthquake will bring about big losses once it happens.

· Landslide: Landslide would have great impact on the connection between tube and land.

The operation risks for SFT are following:

· Fire: Just like tunnels, SFT also has many similar problems such as long distance, humidity, poor ventilation and so on. The air pollution caused by vehicles is very serious in SFT. When fire happens in the SFT, the heavy smoke and heat caused by burning are hard to discharge and finally threat trapped persons’ life. Meanwhile, it also increases the safety risk if there are no special escape ways in the structure.

· Traffic accident: SFT is an enclosure space under water; it would be very difficult to take rescue work when traffic accident occurs. It may cause great casualties and economic losses. What’s more, traffic accident would also trigger other problems, such as fire and dangerous goods leakage.

· Water leak: Waterproofing is also the key point for safety of SFT, because water leak could lead to the public a tremendous psychological fear. Once the leakage occurs, the great pressure water would make leakage further increase. The reliability of waterproof is very important. Connection of tube and construction detail of waterproof should be carefully treated.

· Overload: The risk of overload is relatively small, but overloading can lead to structural damage.

· Environmental impact

· Cost: Due to lots of material and machinery involved in project, estimated cost may be high.

· No Stoppage: It is very difficult to stop the train travelling on such a high speed.

The construction risks of SFT can be separated into foundation construction, tube construction, anchor cable construction and ancillary facility construction. When constructing SFT structure, first, the tube section should be prefabricated at the boatyards near the construction site, and then sealed at both ends by bulkhead. Next; the section can be towed to assigned position by tugboat. The anchor cable installation and deep water pile foundation construction should have in advance been carried out. Once the segment is at assigned position, the floating crane fixed by four wire ropes which are anchored at the lakebed controls the segment of SFT and lets it down to the preset position by special buoyancy balance system. After the sinking, this segment can be connected to previous one. Finally, the bulkhead is removed and waterproof at the connection should be done, and the other ancillary facilities are installed.

7. RISK CONTROL OF SFT

The meaning of risk control is to minimize the risk loss through prior treatment and process control according to the result of risk assessment. The risk control measures can also be taken by three aspects as follows:

· Corresponding to the natural hazard risk of SFT, we should put forward reinforcement and protection methods against hazard under the construction of SFT to improve capacity of disaster prevention. In the one hand, we should establish the system of hazard monitoring and hazard early warning as well as hazard database of SFT project site, which includes hazard’s type, duration, destructive degree and repair measures. On the other hand, the mechanism research of structure damage caused by hazard, nonlinear elastic-plastic analysis by using computer simulation technology and some control technologies and methods of SFT should be carried out.

· Corresponding to the operational risk of SFT, not only should we improve the SFT disaster prevention and relief system, but also ensure SFT facility integrity including smooth line shape, explicit traffic indicator sign and adequate ventilation as well as lighting system. Meanwhile, we may also research the influence of longitudinal ventilation on working fire and smoke emission. The comprehensive set emergency evacuation system are considered and designed, such as special evacuation channel.

· Corresponding to the constructional risk of SFT, we should consider the combined action between structure and environment in each construction
stage. The control section’s structure parameters during the construction of SFT, such as strains and stresses should be monitored in time in order to guide construction and guarantee the constructional reliability of SFT structure.

8. CASE STUDY ON A SFT: TRANSATLANTIC TUNNEL

A Transatlantic tunnel is a theoretical submerged floating tunnel which would span the Atlantic Ocean between North America and Europe. The transatlantic tunnel would be built of 54000 prefabricated sections connected by watertight and vacuum-tight gaskets. Each section of tunnel is to be attached to tethers which are to be affixed to an anchor at the sea floor, which is, in some places almost 8 km deep. The tunnel would hover at about 45 meter below the see surface, ideal to avoid ships and still minimize pressure and also to sway a bit under pressure. A high-speed train could theoretically run from New York to London in 54 minutes. But the train would have to go at a speed of 8000 km/h through a 5000 km long tunnel, which is itself floating in the Atlantic Ocean. To reach this speed, almost a perfect vacuum would have to be maintained in the tunnel and the train would have to be magnetically levitated. There will be 3 rails. Two are bidirectional and one reserve, to be used during accidents and repairs.

Fig. 8.1 Location of Transatlantic Tunnel

8.1 COMPONENTS OF TRANSATLANTIC TUNNEL

Transatlantic tunnel consists of many components. The main components of this Tunnel are listed below.

· Gasket/shell
· Sea anchors
· Utility conduits and service port
· Vacuum pumps
· Maglev train
· Guide ways

8.1.1 Gasket/Shell

As the tunnel is situated at a depth of 30m, it should be perfectly water tight and secondly it should resist the salty sea water and thirdly it should be withstand against hydrostatic forces coming on it. It is made of 4 layers. Outermost layer is constructed of aluminium to resist the salty sea water. Second and third layer is made of the foam to float the tunnel easily in water. Fourth layer is of concrete which gives strength to the tunnel. As the length of tunnel is very large, it is not possible to construct the tunnel at situ. Therefore it is made up of 54000 precast units. These units are casted on shore and transported to place where they have to fix the units with two large floating platforms. A diagram of shell is given in fig.

Fig. 8.2 Shell

8.1.2 Sea Anchors

As the tunnel is in the Atlantic Ocean, it should have to face high current velocity in Atlantic Ocean. The tunnel should not deflect much with water current. Therefore it anchored to the sea bed with the help of steel anchors. The procedure is as follows: First, ropes are attached to a block and this block is inserted in sea bed water come out from top and forms a hydro-statics seal which holds the block firmly in sea bed. A diagram of sea anchor is given in Fig.

Fig. 8.3 Sea Anchor

8.1.3 Service Port

The tunnel is powered by electrically which should be available for entire length of tunnel. These electrical wires are carried out through utility conduits. The two service ports are provided in tunnel, one above and other below the track conduit. These are provided for communication and access for repair works.

Fig. 8.4 Service port

8.1.4 Vacuum Pump

The train is running with such a thrilling speed of 5000 mph in the tunnel. The air resistance is too high on such a high speed. Therefore to reduce it and increase the speed of train, vacuum is created in tunnel. But creating vacuum in such a long tunnel is very difficult task. With available equipments, 100 propellers of most powerful boing jet are require to evacuate the air continuously for 15 days. The vacuum pumps are installed throughout the length of tunnel to maintain the vacuum in it.

9.1.5 Maglev Train

These are magnetically elevated trains. These trains do not run over the track but floats slightly above the track. Thus we can achieve practically zero tractive resistance between train and track. Further this train will pass though vacuum, which increase the speed of train. The sensation of flying at 400mph with no engine noise or vibration will make the journey through the tunnel a unique experience. Special rotating and pivoting seats are provided to further reduce the effect of gravitational force. A diagram of train is given in Fig.

Fig. 8.5 Maglev Train

Figure showing the various components of transatlantic tunnel

Fig. 8.6 Components of Transatlantic Tunnel

9.2 CHALLENGES TO BE FACED

· Cost: - Due to lots of material and machinery involved in project, estimated cost is nearly 1.2 Thousand core dollars.

· Fire: - It is difficult to rescue people if fire will break out in train and also to face the problems due 4. No Stoppage: - It is very difficult to to the smoke of fire.

· Collision: - If in case of collision of two trains took place, it is very difficult to rescue the people.

· No Stoppage: - It is very difficult to stop the train travelling on such a high speed.

9. CONCLUSION

This paper is an attempt to give a simple overview of SFT as a structure. Basic principles, structure, design features, advantages are discussed, but not in great detail, the intension has been to highlight some of the characteristics of this promising structure for the future.

The submerged floating tunnel will set up new trends in transportation engineering and which shows with the advances in technology that will reduce the time required for travelling and make the transportation more effective by hiding the traffic under water by which the beauty of landscape is maintained and valuable land is available for other purposes. Benefits can be obtained with respect to less energy consumption, air pollution and reduced noise emission. For wide and deep crossings the submerged floating tunnel may be the only feasible fix link, replacing present day’s ferries and providing local communities with new opportunities for improved communication and regional development.

The added knowledge from all the presentations in this symposium should be the best reason to go ahead with SFT or Archimedes Bridge and soon produce a full scale project in competition with all the other alternatives. But in some instances, SFT has no real competition; it is the only possibility for a fixed link.

11. REFERENCES

1. Bernt Jakobsen, (2010), Design of the Submerged Floating Tunnel operating under various conditions, Procedia Engineering ,vol 4 pp 71–79.

2. Christian Ingerslev, (2010, Immersed and floating tunnels, Procedia
Engineering, vol 4 pp 51–59.

3. Håvard Østlid,(2010), When is SFT competitive?, Procedia Engineering, vol 4 pp 3–11.

4. S.Tariverdil et.al, J.Mirzapour, M.Shahmardani, R. Shabani , C.Gheyretmand, ( 2010) Vibration of submerged floating tunnels due to moving loads, Procedia Engineering.

5. Tesi Di Dottorato,(2010), The Development Of Submerged FloatingTunnels As Innovative Solution For Waterway Crossings, Giulio Martire,vol 1.

6. Walter C. Grantz, P.E, (2010) Conceptual study for a deep water, long span, Submerged Floating Tunnel (SFT) crossing, Procedia Engineering.

SOLAR PANELED ROAD

2016-06-22T09:32:00.000-07:00

1. INTRODUCTION

Nature has provided bountiful resources surrounding us for sustenance of a better life. These resources, along with manpower and capital, play a crucial role for expansion to national output. However, the advancement of modern civilization has had a great impact on our planet's natural resources. Therefore sustainable solutions are a requirement for modern design problems due to society’s overreliance on natural resources. Thus innovative ideas which focus on sustainability must be considered as a key priority for design and optimization.

One of the primary solutions for this problem is the increase in use of renewable energy resources. Different types of renewable energy resources are solar, wind, ocean and geothermal energy. Among these, solar energy is the only resource which is abundantly available and evenly distributed worldwide. Hence developing technologies to capture this solar energy is the need of the hour.

In order to overcome the relatively low efficiency of the solar panels, significantly large amount of open spaces are required for the production of electricity in the photovoltaic solar panel applications. Since availability of large open spaces is on the decline near the urban areas, the solar panels can only be installed in remote areas. But this can lead to huge energy losses. The low efficiency of the solar panels as well as the necessity to deal with the transmission losses makes the use of solar panels a non-viable economical option to produce electricity. In order to make the solar power a viable economical option, open spaces that are situated close to the high energy demand areas must be identified. Hence, it is proposed that open spaces such as the roads, parking lots, bicycle lanes, footpaths etc. be utilized for this purpose. In order to use these open spaces for producing electricity using solar panels, recently, the concept of solar roadways have been introduced.

The Solar Roadway is a series of structurally-engineered solar panels that are driven upon. It would utilize the use of roads that would be covered by photovoltaic panels. The idea is to replace all current petroleum-based asphalt roads, parking lots, and driveways with Solar Road Panels that collect energy to be used by our homes and businesses. . The ultimate goal is to store excess energy in or along-side the Solar Roadways.

Through the issues associated with urban heat islands it is known that pavements are often exposed to a vast amount of solar radiation throughout the day. If it was possible to convert a portion of this energy to usable forms, civil and infrastructure issues could be solved simultaneously. Two methods have already been developed to generate energy from roads, using asphalt pavement as a solar thermal collector and installing piezoelectric generators to collect vibration energy from the traffic load on the pavement. Recent studies have also begun to use thermoelectric systems to extract heat energy from roads and directly convert it to electricity. This project is taking a different approach to the concept as, through photovoltaics. Radiation is directly converted into electricity on the surface of the panel without a heat or vibration conversion.

1.1 SOLAR ROADWAYS

A solar roadway is a road surface that generates electricity by solar power photovoltaic cells. It consists of structurally engineered solar panels that we drive on.
Each Solar Road Panel (roughly 12’ by 12’) interlinks with neighbouring panels to form the Solar Roadways system. The Solar Roadway replaces our crumbling petroleum-based asphalt highway infrastructure with an intelligent road that pays for itself through the generation of electricity. The Solar Roadway generates electrical power from the sun and becomes our nations decentralized, intelligent, self-healing power grid, replacing our current deteriorating power distribution infrastructure.

The Solar Roadway distributes its electrical power to all businesses and homes connected to the system via their parking lots and driveways (made up of Solar Road Panels). In addition to electrical power, data signals (cable TV, high-speed internet, telephone, etc.) also travel through the Solar Roadways, which acts as a conduit for these signals (cables). This feature eliminates the unsightly power lines, utility poles, and relay stations we see all over the countryside. It also eliminates power interruption caused by fallen or broken electrical lines or poles.

Fig 1.1: Solar roadways

1.2 PHOTOVOLTAIC

The main philosophy of solar roadways is to convert solar energy into electrical energy by the principle of photovoltaics. Photovoltaics (PV) is a method of generating electrical power by converting solar radiation into direct current electricity using semiconductors that exhibit the photovoltaic effect. Photovoltaic power generation employs solar panels composed of a number of solar cells containing a photovoltaic material.

To understand how photovoltaic operate, the nature of sunlight has to be understood. The structure of all type of light consists of electromagnetic radiation which is similar to micro and radio waves. When an electromagnetic radiation becomes incident on a semiconductor material (p-n junction), the photons are absorbed by the material and electrons are knocked loose from the atoms in the semiconductor material. If electrical conductors are attached to the positive and negative sides, forming an electrical circuit, the electrons can be captured in the form of an electric current, that is, electricity. This electricity can then be used to power a load, such as a light or a tool.

2. TYPICAL SOLAR ROADWAY

A solar roadway is a series of structurally engineered solar panels that are driven upon. The idea is to replace current petroleum-based asphalt roads, parking lots, and driveways with solar road panels that collect energy to be used by homes and businesses, and ultimately to be able to store excess energy in or alongside the solar roadways. The renewable energy generated by solar road panels will replace the current need for fossil fuel, which in turn reduces the greenhouse gases.

Parking lots, driveways, and eventually highways are all targets for the panels. If the entire United States Interstate Highway system were surfaced with Solar Roadways panels, it would produce more than three times the amount of electricity currently used nationwide.

Existing prototype panels consist of three layers.

Road surface layer - translucent and high-strength, textured glass, that is rough enough to provide sufficient traction, yet still passes sunlight through to the solar collector cells embedded within, along with LEDs and a heating element. This layer needs to be capable of handling today's heaviest loads under the worst of conditions and to be weatherproof, to protect the electronics layer beneath it.

Electronics layer/Optical layer - It transmits the load around the solar cells. It contains a microprocessor board with support circuitry for sensing loads on the surface and controlling a heating element with a view to reducing or eliminating snow and ice removal as well as school and business closings due to inclement weather. The microprocessor controls lighting, communications, monitoring, etc. With a communications device every 3.66m (12 feet), a solar roadway can be an intelligent highway system.

Base plate layer - While the electronics layer collects energy from the sun, it is the base plate layer that distributes that power as well as data signals (phone, TV, internet, etc.) down the line to all homes and businesses connected to the solar roadway. It has to transmit the load to a pavement, subgrade, or base structure. It needs to be weatherproof to protect the electronics layer above it.

Fig 2.1: Exploded view of a conceptual solar road panel

(http://www.tac-atc.ca)

When multiple Solar Road Panels are interconnected, the intelligent Solar Roadway is formed. These panels replace current driveways, parking lots, and all road systems, be they interstate highways, state routes, downtown streets, residential streets, or even plain dirt or gravel country roads. Panels can also be used in amusement parks, raceways, bike paths, parking garage rooftops, remote military locations, etc. Any home or business connected to the Solar Roadway (via a Solar Road Panel driveway or parking lot) receives the power and data signals that the Solar Roadway provides. The Solar Roadway becomes an intelligent, self-healing, decentralized (secure) power grid.

3. STRUCTURAL REQUIREMENTS

The structural design requirements for a solar road panel are as follows:

· The structure must be able to support the cyclic distributed load from vehicle tires without failing through deformation, fracture.

· The transparent layer cannot deflect over the cell compartments so much that the layer transmits load to the solar cells.

· The structure must be corrosion resistant to potential contaminants.

· The design must be modular and facilitate easy maintenance.

· For this prototype's purposes, the panel must be made out of readily available components and materials.

· The weight of the panel must be low enough such that it can be easily maneuvered for testing and installation purposes.

4. ELECTRICAL DESIGN REQUIREMENTS

The electrical design requirements for a solar road panel are as follows:

· The panel should be designed so that no shading of the solar cells occurs.
· The interconnection between the cells should be strong enough to withstand potential deflections from the optical layer.
· The panel must be weatherproof so that water and other contaminants are not able to interfere with the electronics.
· There must be a diode installed on the output electrical line of the panel to block reverse currents, as this would damage the solar cells within the panel.

5. DESIGN

In The University of Western Ontario, the design of the panel was done by COMSOL Multiphysics, an engineering simulation software. COMSOL Multiphysics which has both the modeling and simulation capabilities for Multiphysics systems was used to ascertain the feasibility for different vehicular applications and for suggesting future material The model created in the COMSOL Multiphysics for the analysis purpose consists of a vertically hollow square base layer with sides 4 meters in length, 0.5 meter in height and 0.1 meter in thickness..The base layer is considered to be made up of concrete, and covered with a transparent cover of size 4 m and thickness 0.01 m made up of acrylic plastic, whose material properties are given in Table 1. The acrylic sheets have a working temperature range of -40°C up to 93°C, and the elastic properties are assumed to remain constant in this temperature range.

Table 5.1: Material properties for Acrylic plastic and Concrete

(Source: ir.lib.uwo.ca)

As the solar roadways panels are to be laid over the existing roads, the primary loads acting on the solar roadways panels are the vehicle loads. For the analysis, the loads associated with the vehicles are selected based on the specification from American Association of State Highways and Transportation Officials (AASHTO). Two types of loadings, H loading and HS loading are given by AASHTO. H loading consists of a two axle truck and HS loading consists of a tractor truck with semi-trailer. In general, there are four standard classes of highway loading conditions, namely H15, H20, HS15 and HS20. The number following the H and HS letter denotes the gross weight in tons of a standard truck. The HS20 standard truck load, a maximum stress of 1.82x103Mpa is much higher when compared to the ultimate tensile strength of 69Mpa and the displacement results indicate that maximum surface displacement was also very high at 1.12 meters. Hence it can be concluded that the selected top cover material is not suitable for the applied load and this cannot be used as a top cover for solar roadways panel, where vehicles of size similar to a truck are moving over it.

As the selected material failed for the load of a truck, in order to test the maximum load the material selected for the top cover of solar roadways panel can take on, stress and displacements due to a car, bicycle and a motorbike load moving over the solar panel were analyzed. The specifications of the vehicles are given in table 2.According to standard specifications and code of practice for road bridges (IRC: 6- 2000), the car and the motorbike belongs to Class A loading and bicycle belongs to Class B loading.

Table 5.2: Specifications of car, motorbike and bicycle used in the analysis

(Source: ir.lib.uwo.ca)

The size of selected base layer was 1.5 m x 0.2 m x 0.1 m, covered by a transparent top cover of size 1.5 meters and with a thickness of 10 mm. It was found that the total weight of the bicycle, 90.7kg (including weight of the bicycle and person travelling on it) caused a stress of 20.67MPa, which is quite low when compared to the ultimate tensile strength of 69MPa. The maximum surface displacement was 2.05mm, which is well below the AASHTO design standard. Whereas in the analysis considering
motorbike and car it was found that if the young’s modulus is increased from 50.8x109 to 50.8x1010 Pa, a thickness of 15mm and 25.4mm was suitable for both vehicles respectively.

6. WORKING

· When a solar panel exposed to sunlight , the light energies are absorbed by a
semi conduction materials.
· Due to this adsorbed energy, the electrons are liberated and produce the external DC current.
· The DC current is converted into 240-volt AC current using an inverter for different applications.

7. MECHANISM

• First, the sunlight is absorbed by a solar cell in a solar panel.
• The absorbed light causes electrons in the material to increase in energy. At the
same time making them free to move around in the material.
• However, the electrons remain at this higher energy for only a short time before
returning to their original lower energy position.
• Therefore, to collect the carriers before they lose the energy gained from the
light, a PN junction is typically used.
• A PN junction consists of two different regions of a semiconductor material (usually silicon), with one side called the p type region and the other the n-type region.
• During the incident of light energy, in p-type material, electrons can gain energy and move into the n-type region.
• Then they can no longer go back to their original low energy position and remain at a higher energy.
• The process of moving a light- generated carrier from p-type region to n-type region is called collection.
• These collections of carriers (electrons) can be either extracted from the device to give a current, or it can remain in the device and gives rise to a voltage.
• The electrons that leave the solar cell as current give up their energy to whatever
is connected to the solar cell, and then re-enter the solar cell. Once back in
the solar cell, the process begins again.

8. APPLICATIONS

8.1 ILLUMINATED ROADS

Unlike the dark roads we drive on by night today, the Solar Roadways will have LEDs which will "paint" the lanes, and can be instantly customized as needed. The LEDs could be utilized to create messages on the roads to warn drivers of detours, accidents, or construction works up ahead. With an illuminated highway, accidents will be reduced and night time driving will be safer.

Fig 8.1: Solar roadway with pavement markings
(http://solarroadways.com)

8.2 SNOW / ICE MANAGEMENT

A benefit to the use of solar roadways is that the de-icing of roads will not be required; this is due to panels being capable of self heating, and the glass incorporating the same heating elements of a car’s rear screen. The panels will have sensors which will determine when the temperature falls below a certain point and will activate the heating system which will prevent the buildup of snow and ice. Thus eliminates the use of deicing salts and the impacts that arise due to their use such as, contaminated surface runoff and rusting of road structures and vehicles.

8.3 TRAFFIC MANAGEMENT

Each Solar Road Panel contains a microprocessor that monitors and controls the panel, while communicating with neighboring panels and the vehicles traveling overhead. The dashed road lines that are seen on highways can travel alongside at the designated speed limit, thus helping us to maintain proper speed. The road can warn about traffic congestions ahead and even recommend detours around it. It can even notify law enforcement to assist in tracking down stolen vehicles or
suspects’ cars equipped with GPS tracking devices. Crosswalk panels can alert drivers when pedestrians are on the crosswalk. Once the crosswalk panels detect a pedestrian, the LEDs within the crosswalk begin flashing and a warning is displayed in front of oncoming vehicles. Wildlife protection system works in the same way. If a vehicle crosses the center line too many times within a given distance, a ring of LEDs can be drawn around the vehicle, which will travel with it indefinitely. This will warn other drivers of a potential danger and will alert law enforcement officials of a potential problem. The Solar Roadways could drastically reduce the number of deaths/injuries caused by impaired driving. It can save electricity by turning on roadway lighting in remote areas only when a vehicle comes along.

Fig 8.2: Pedestrian warning system Fig 8.3: Wildlife protection system (http://solarroadways.com)

8.4 NATIONAL SECURITY Trucks with hazardous materials can be tracked and monitored. Suspected terrorist's vehicles can be tracked. Public buses and school buses can be tracked. These vehicles can be fitted with controls to shut down their engines and/or apply their brakes.

8.5 HOMES / BUSINESSES

Businesses will be able to have solar parking lots, which will enable them to quickly go off grid as well as offer their customers the convenience of allowing their electric vehicles to recharge while they are shopping, eating, working etc. They will no longer have the expense of snow removal. Their parking lots will be safer at night with the light provided by the LED's. Walkways can be replaced with similar solar panels, enabling more energy collection, and the safety features like lighting and heating. A solar driveway will have many features, including LED lit address markers and the ability to add customized wording, such as "Happy Birthday Heather!" or "Wedding reception here. The driveway will also become an instantly customizable sports court. One minute, teenagers can be playing basketball and, at the touch of a button, the younger children can play Four Square or Hopscotch or any other game that the homeowner would like to configure. Pool surrounds and courtyards will be another ideal application for homeowners.

Fig 8.4: Sports court created from solar roadways

(http://solarroadways.com)

8.6 SOLAR ROADWAY LIGHTING

The solar roadways can be supplemented by solar-powered led roadway lighting system. Highly efficient, long lasting, environmentally friendly and controllable LEDs have opened up a whole new world of possibilities for lighting. In some remote areas where the grid power cannot reach, solar powered lighting using high-power LED provides a promising solution. LED will reduce the power consumption as well as LLP (loss of load power) and thus is the best choice for solar roadway lighting. A new pilot project by Philips and the Kenyan Urban Roads Authority to install solar-powered LED street lighting in Nairobi has the potential to generate up to 100 per cent energy savings, if implemented on a wide scale across the country. The key to the breakthrough lies in the combination of new High Brightness LEDs with unique patented optics and an intelligent controller which lies at the heart of the solution.

Fig 8.5: Diagram showing the working of solar road lighting (http://www.philipsafricaroadshow.com)

8.7 TRAFFIC LIGHTS

Solar traffic lights are signaling devices powered by solar panels positioned at road intersections, pedestrian crossings and other locations to control the flows of traffic.The electricity generated by the solar roadways can be used to function the traffic lights.

8.8 TRAFFIC SIGNS

LEDs can be embedded in standard highway warning and regulatory signs to outline either the sign itself or the words and symbols on the sign.. In general, embedded LED units are used to:

• Improve driver compliance with regulatory signs through improved conspicuity; and
• Enhance visibility and recognition of regulatory and warning signs to drivers, especially under low-light or low-visibility conditions. Solar roadways can be used to power these equipments

Fig 8.6: (a) solar powered road sign (b) solar powered traffic light

(http://www.theworld-export.com)

9. COMPARISON BETWEEN BITUMINOUS ROADS AND SOLAR ROADWAYS

Bituminous roads are those roads in which some binding material such as bitumen, coal-tar or asphalt is used in surfacing. Such roads are also known as black top roads. The following are the various types of bituminous surfaces:

1) Surface painting or surface dressing

2) Bituminous macadam

3) Bituminous concrete

4) Sheet asphalt or asphaltic mat

Traditional roads are chiefly composed of aggregates and a binding material whereas solar roadways are made of glass, solar cells and concrete. Bituminous materials or asphalts are extensively used for roadway construction, primarily because of their excellent binding characteristics and water proofing properties and relatively low cost. Despite the benefits there are also numerous drawbacks such as brittleness at low temperatures, softness at high temperatures and environmental issues such as high energy demand and pollution due to its production.

Asphalt works, in many ways, and is convenient to lay-down, compared to other methods. It has carried our automotive infrastructure into the 21st century. But there are hidden costs that are making it increasingly difficult and expensive to continue favoring asphalt as the predominant road-paving model for the entire nation. That’s why asphalt is not ideal for road construction. Bitumen roads have a design life of 10 to 20 years and require resurfacing every seven years approximately, whereas solar roadways have a design life of twenty one years.

Solar Roadways can pay dividends for the public budget, making our spending on infrastructure more efficient and significantly reducing electricity costs to consumers and businesses. They can make the emerging electric vehicle economy far more affordable, and easier to manage. They can help us eliminate hundreds of billions of dollars per year, or more, in externalized costs of burning fossil fuels. And, we can lead the world in powerful clean energy technology exports, capable of rolling back massive pollution and greenhouse gas emissions.

Road construction and expansion have major environmental impacts. The environmental impact of road projects include damage to sensitive ecosystem, permanent disruption to local economic activities ,demographic change, accelerated urbanization and the introduction of diseases due to pollutants. In addition, there are also the emissions which are released in the various stages of construction process. The amount of greenhouse gases released directly and indirectly by an individual, organization or event is known as carbon footprint. The road carbon footprint exists as bitumen requires extracting, refining and transportation to the location in order construct the road, with the addition of the maintenance and repair energy requirements later in the life of the road. Vicroads a company based in the state of Victoria, Australia, recently carried out a project to determine the carbon footprint of road construction. The company duplicated the Mickleham Road, the road was 2.4km long and consisted of 4 lanes, and they also carried out maintenance work for the project which included installation of new traffic signals, street lighting and drainage. On the completion of the project it was determined that a total of 1,820 tonnes of green house gases were released. From the data collected it was determined that 190 tonnes of CO2/km/lane was emitted for the project. To offset the emissions released for the total project required the planting of approximately 7,500 trees.

As solar roadways will not be constructed by the use of bituminous materials it will reduce the use of fossil fuels, as mentioned previously the obtaining and applying of bitumen causes damage and releases emissions into the environment. The main environmental impacts that arise due to the solar roadways are the pollution which is generated during their manufacturing of the road sections, but this is offset by the panels’ ability to recoup it by the solar energy transfer into electrical power.

The production of the glass surface panels consumes a lot of energy as the main materials in the production of glass require them to be melted to high temperatures reaching 1500°C, although this is a high temperature an additive has been added to lower the temperature. In the UK the lifecycle CO₂ emissions for a photovoltaic system is 58g CO₂eq/kWH. The same system if installed in southern Europe, Spain would have lifecycle CO₂ emissions of 35g CO2eq/kWH the decrease is due to their being more sunlight present which means greater operating hours.

A benefit to the use of solar roadways is that the de-icing of roads will not be required. One of the impacts associated with bitumen roads is the use of de-icing salts. There are numerous varieties of de-icing salts which are used on our roads; calcium chloride, potassium chloride, magnesium chloride and sodium chloride. De-icing salts used by countries for winter road protection accumulates to 51% of the worlds output of salt.

The use of salts has many effects on the environment, damage occurs to vegetation, water, roads, road structures and vehicles. As salt is very soluble it will dissolve with water, and this is the major problem when water seeps into the ground or water courses where it alters the properties of the water. The chloride ions present in the salt then raise the chloride concentrations of the streams, lakes, soils and groundwater sources causing them to have adverse effects on the aquatic plants and land. The use of salts also increases deterioration rate in roads and structures as the chloride ions react with the reinforcements and cause rust to form and leads to corrosion.

One of the major drawbacks in the use of bitumen is the failure of road surfaces due to water infiltration into the layers of the road. The deterioration rate increases due to the environmental factors of freeze and thaw. With solar roadways the surface will be 100% water proof and this will prevent the penetration of water into the lower layers. Thus the solar roadways will require lesser maintenance. Moreover in order to carryout necessary repairs and installations of underground utilities, excavation of the roads is required. Since solar roadways consists of panel sections, if the utilities require repair or replacement the road can be cordoned off in sections without excavation of soil or road layers. This will therefore lead to faster installation and repair process time.

Another advantage of solar roadways is the micro texture of the surface unlike the bitumen roads where the aggregates lose their roughness (become smooth) due to weathering and polishing effects due to traffic. The solar roadways surface will experience these factors but as glass has high resistance to wear and tear, this problem is less likely to affect solar roadways.

The panels will get damaged and will not supply any electricity if subsidence on road occurs .Subsidence is a major problem as it cannot be determined when it will occur. Traditional roads are able to flex when subsidence occurs, but the solid state of the solar roadways panel poses a problem. Another problem which will be encountered in its implementation is the geometry of the road. Bitumen roads curve naturally and smoothly in corners without any restriction whereas a solar roadway consists of rigid structure and it may create problem in achieving the natural curve of the road.

10. ADVANTAGES AND DISADVANTAGES

10.1 ADVANTAGES

Ø Renewability and life-span

The main advantage of the solar roadway concept is that it utilizes a renewable source of energy to produce electricity. It has the potential to reduce dependence on conventional sources of energy such as coal, petroleum and other fossil fuels. Also, the life span of the solar panels is around 20 years, much greater than normal asphalt roads, which only last 7–12 years.

Ø Military and rescue assistance

In the event of an environmental disaster or military emergency, solar roadways would provide power when it is needed most. As solar power is renewable, it obviously requires no external connection to an artificial power source.

Ø Roadways already in place

Another advantage of solar roadways is that they do not require the development of unused and potentially environmentally sensitive lands. This is currently a very controversial issue with large photovoltaic installations in the South western US and other places. But since the roads are already there, this is not an issue. Also, unlike large photovoltaic installations, new transmission corridors – perhaps across environmentally sensitive land – would not be required to bring power to consumers in urban areas. Transmission lines could simply be run along already established roadways.

Ø Lighting up of roads

By adding LEDs beneath the transparent panel, road can be lightened up for safe night travel and aesthetic look.

10.2 DISADVANTAGES OF SOLAR ROADS

Ø Maintenance costs:

They are more because road surfaces accumulate rubber, salt, soil and other substances that block sunlight and must be removed. The durability of the panels may also be less, further increasing maintenance costs.

Ø Seasonal efficiency:

In India the solar road will work efficiently in summer, while it will give comparatively less efficiency in other seasons due to lack of solar radiations. Where as in the countries where summer lasts for more than half of year this technique can be efficiently used.

11. CONCLUSION

The need of the hour for an alternative energy source is increasing at an alarming rate. We can't wait any longer to find a replacement for oil, which is rapidly disappearing. The solar roadways if implemented can be a solution for all our energy concerns.

In developing countries the major part of the geographical area is to be explored in terms of road connectivity. So instead of implementing the higher targets roads to be developed per day such countries can reduce the target and develop solar road so they could improve economy with infrastructure.

Generally the Solar Roadways will provide safer driving conditions, snow and ice management, traffic management, wild life protection. It is compiled solar panels which to replace ordinary asphalt street as it has better features. It is able to produce electricity and heating elements. It is designed with LED lights which able to act as traffic lines, road indicators, construction detours and streetlight for roadways. It would be solar panel field, internet distribution system, and communication system in the future. The reasons why solar roadways project is viable are to lessen fossil-fuel dependency and reduce global warming activity. It also has some of its drawbacks such as high cost, durability, and weather. However, we believe that we would able to overcome those limitations eventually in order to serve the society with greater efficiency.

12. REFERENCES

1. Kulkarni, A.,(2013), “Solar Roadways-Rebuilding our Infrastructure and
Economy”, International Journal of Engineering Research and
Applications(IJERA), Vol. 3, Issue 3, pp.1429-1436, May-Jun 2013

2. Northmore, A., Tighe, S.,(2012),“ Innovative Pavement Design: Are Solar Roads
Feasible?” 2012 Conference of the Transportation Association of Canada Fredericton, New Brunswick

3. Rushing, S.T., Tingle.,S.J.,(2009), “Full-scale evaluation of mat surfacings for
roads over sand subgrades” Journal of Terramechanics, vol 46 (2009) 57–63

4. Selvaraju, K.R.,(2012), “Characterization of Solar Roadways via computational
and experimental investigations”, ir.lib.uwo.ca

5. Symeoni, A.,(2012), “A review on energy harvesting from roads”,
http://kth.diva-portal.org.pdf