Civil Engineering

English Bond and Flemish Bond – Features & Difference

2019-12-07T20:52:00.001+05:00

English Bond and Flemish Bond – Features & Difference

The English bond and the Flemish bond are the two most common types of brick masonry used in wall construction. An English bond is formed by a brick construction pattern with alternate brick courses laid as stretchers and headers. A flemish bond is a design of brick building consisting of alternate stretchers and headers for each course.

English Bond

For almost all wall thicknesses, an English bond can be built Among all other bonds, this bond is the strongest. This bond is made up of alternate header and stretcher courses. The vertical joints overlap one another. This is also followed by the stretcher course's vertical joints. The vertical joints are broken by using a queen closer to prevent the joints from forming inline. The queen closer is placed for each heading course after the quoin header.

Features of English Bond

The basic features of English Bond are:

No continuous vertical joints are formed.
In the elevation, the alternate course either shows headers or stretchers.
Every header in an alternative course comes centrally over the joint formed by two stretchers below it.
The stretchers have a minimum lap of one-fourth their length over the headers. This is the case for the stretcher course.
Those walls with even multiple half bricks show the same appearance on both the faces. Hence a course that shows stretchers on the front face would show stretchers on the back face.
Those walls with odd multiple half bricks show stretchers on one face and the headers on the other dace.
The middle portion of the thicker walls consists of headers.
Queen closer is not required for a stretcher course. It is used for the header course placed just after the quoin header. No header course should start with the queen closer.
The joints formed in the header course are greater (twice) than the stretcher course. Hence the joint in the header course is made thinner compared to the joints in the stretcher course.

Flemish Bond

A Flemish bond pattern consists of each course of alternate headers and stretchers. Every alternate course starts with a quoin header at the corner. To the next of quoin header, quoin closer is placed in alternate courses to develop face lap. The patterns arrange such that every header is centrally supported over the stretcher below it.

Flemish bonds can be either:

Double Flemish Bond
Single Flemish Bond

1. Double Flemish Bond

In each course, a double flemish bond with alternating headers and stretchers. The feature of the double flemish bond is that it has the same color on both the front and back sides. This feature, therefore, gives a better appearance for all wall thickness compared to the English bond.

Features of Double Flemish Bond

The basic features of Double Flemish Bond are:

Each Course has headers and stretchers placed alternately.
The facing and backing of the wall have the same appearance.
In alternate courses, quoin closers are placed next to quoin headers.
The walls with odd multiple of half brick employ half bats and three-quarter bats.
The walls with even multiple of half bricks, do not require bats.

2. Single Flemish Bond

In each case, a single flemish bond consists of the double flemish bond on its face and the English bond as heartfelt support. The bond, therefore, makes use of both English and Flemish bond power. This bond can be used to build walls of not less than one and a half brick with a thickness. The double flemish bond facing is used with costly bricks of good quality.

Also Read Types Of Masonry Construction Based On Material

Difference between English and Flemish Bond

ENGLISH BOND	FLEMISH BOND
Bond pattern with alternate header and stretcher course	Bond Pattern with each course having alternate header and stretcher
More strength given for bricks with thickness greater than one & half brick	Less strong and compact compared to English bond
Less pleasing appearance	Appearance is more attractive and pleasing
Expensive	Economical
No strict supervision and skill is demanded	Requires good workmanship and careful supervision.

Types of Foundation

2019-12-03T08:00:00.000+05:00

Classification of Foundation

On the basis of depth, foundations are broadly classified into two categories.

Shallow foundation
Deep foundation

Shallow foundation :

"The foundation is known as the shallow foundation that immediately beneath the lowest part of the structure, near to the ground level."

“A shallow foundation is a type of building foundation that transfers building loads to the earth very near to the surface, rather than to a subsurface layer or a range of depths as does a deep foundation.”

Such foundations are mostly placed below ground level on the first hard strata. Shallow foundations are those that at shallow depth transmit the loads to the soil.

When the soil at shallow depth is strong enough to withstand the load, a shallow foundation is provided The ratio of foundation depth D to foundation width, B is equal to or less than 1 for shallow foundations.

For shallow foundation:

D / B < 1

Deep foundation :

The foundation built sufficiently below ground level is called the deep foundation at its base with some artificial arrangements such as piles, wells, etc.

Deep foundations are those transiting the load into deeper soil. Deep foundations are required when a structure can not be supported by the soil at shallow depth and a hard stratum is available at larger depth.

For deep foundations, the ratio of the depth of the foundation to the width of the foundation is greater than 1.

D / B > 1

Types of shallow foundation:

Spread footing or open trench foundation.
Raft or Mate foundation.
Stepped footing.
Inverted arch footing.

Spread footing or open trench foundation:

The spread foundation is the shallow foundation type. It is defined as the structural components used to support the column and wall as well as to transmit and distribute the load on the structure to the soil.

In plan, the shape can be circular, square and rectangular.

In such foundation, the spread is given under the base of a wall or a column by providing offsets. This spread is known as footing and the foundation itself is called spread footing.

Wall footing, Masonry pillar footing, and Concrete column footings. ( isolated and combined) are the types of spread footing.

Wall footing:

This is a typical and simplest form of spread footing. It consists of the number of brick courses, the lowest being usually twice the above wall thickness.

By having 50 mm offsets on either side of the wall, the base width of the wall is increased.

Each course usually has a depth of 100 mm.

The course at the bottom is 200 mm deep.

The size of offsets is slightly more in the case of stone walls.

Used for ordinary building walls.

Masonry wall footing:

The isolated footing is used to support the individual pillars and columns constructed in brick or stone masonry.

Concrete column footing:

These are either stepped type, type of slate or type of slope with projections in the concrete base. Reinforcement is also provided at the base to support heavy loads.

Raft or Mate foundation:

The foundation that consists of a thick R.C.C slab that covers the entire area in the form of a mat is known as a raft or mat foundation.

The entire area is excavated to the specified depth in the construction of the Raft Foundation.

The bed is compacted and water-sprinkled.

A layer of lime concrete or lean concrete (1:8:16) is then laid to an appropriate thickness to act as a base cover.

The reinforcement is laid after that. The reinforcement consists of closely spaced bars placed between them at right angles.

Then the cement concrete (1:2:4) is laid and compacted to the thickness required.

This type of foundation is useful for public buildings, office buildings, school buildings, residential quarters, etc, where the ground conditions are very poor and bearing power of the soil is so low that individual spread footing cannot be provided.

STEPPED FOUNDATION :

Another type of foundation is stepped foundation, For Stepped Foundation Construction, excavation is performed in steps with the short length and uniform thickness and the masonry work is performed on the horizontal concrete bed thus prepared.

If the structure can be slipped body-wise, R.C.C piles can be driven on the sloping side along with its base concrete.

Strap footing :

A strap footing is a component of a building's foundation. It is a type of combined footing, consisting of two or more column footings connected by a concrete beam.

This is the most common type of foundation used where you have a solid soil base and a logged area of nan-water.

With this type of foundation, most small buildings of just one floor are constructed.

Depending on the recommendations of the structural engineer, the size of your foundation for the small building could be 600 mm to 1200 mm.

Types of deep foundation:

pile foundation

well foundation

Pile foundation :

A pile is basically a long cylinder of a strong material like concrete that is pushed into the ground to act as permanent support for structures built on top of it.

The foundations of the pile are deep foundations. These are composed of long, slender, columnar structures that are usually made of steel or reinforced concrete, or sometimes wood. When its depth is more than three times its width, a foundation is described as' piled.

Pile foundations are used when the surface has a layer of weak soil. This surface can not bear the building's weight, therefore the building's loads must bypass this layer and be moved to the layer of stronger soil or rock below the weak layer.

it is also when there are heavy concentrated loads in a house, such as a high-rise tower, bridge, or water tank.

Types of Pile Foundation

01. Based on Material:

Timber pile

Steel pile

Concrete pile

Composite pile

02. Based on Shape:

Cylindrical pile

Tapered pile

Under-reamed pile

03. Based on Load Transfer Mode:

End bearing pile

Friction pile

04. Based on Construction Method:

Cast-in-site reinforced concrete

Precast reinforced concrete

05. Based on the Installation Method:

Bored pile

Driven pile

Vibrated pile

Well foundation:

Well foundation is a type of deep foundation that is usually provided for bridges below the water level. Cassions or well have been in use since the Roman and Mughal periods for bridge foundations and other structures.

How to calculate cement sand and aggregate quantity in concrete

2019-12-02T08:00:00.000+05:00

Quantities of materials for concrete such as cement, sand, and aggregates for production of required quantity of concrete of given mix proportions such as 1:2:4 (M15), 1:1.5: 3 (M20), 1:1:2 (M25).

We assume that we have 30 cft volume of concrete and the mixing ratio is 1:2:4 (M15).
So we know that the unit weight of concrete is 150 lbs per cubic foot. so, first of all, we need to find the weight of 30 cft concrete.

Weight of 30 cft concrete

30 x 150 = 4500 lbs

We know that this is the weight of wet concrete so now we will find the dry weight of concrete.

for converting wet concrete weight to dry concrete weight the weight of wet concrete multiply with 1.54.

(If you want to know why we multiplied it with 1.54 then Read this :

Quantity Of Cement And Sand Calculation In Mortar CFT )

Dry weight of concrete

4500 x 1.54 = 6930 lbs

Now we will calculate the quantity of cement, sand, coarse aggregate and water.

Calculation

First of all, we will find the sum of ratio

Sum of ratio = 1+2+4 = 7

Sum of ratio = 7

Now

Quantity of cement =

( 1 ÷ 7 ) x 6930 = 990 lbs

We know that 1 Kg = 2.204 lb so

990 ÷ 2.204 = 449.18 kg say 150 kg

We also know that the weight of1 bag of cement is 50 Kg so

150 ÷ 50 = 3 bags

Quantity of cement = 3 Bags

Quantity of sand =

( 2 ÷ 7 ) x 6930 = 1980 lbs

Quantity of sand in kg =

1980 ÷ 2.204 = 898.36 kg say 900 kg

Quantity of sand = 900kg

Quantity of coarse aggregate =

( 3 ÷ 7 ) x 6930 = 2970 lbs

Quantity of coarse aggregate in kg =

2970 ÷ 2.204 = 1347.54 say 1348 kg

Quantity of coarse aggregate= 1348 kg

(Note = 0.4 to 0.6 water-cement ratio used in M15 concrete. we will take o.5 w/c ratio)

Quantity of water =

0.5 x 150 = 75 liter

(150 is the weight of cement)

Quantity of water = 75 liters

Quantity of material in 30 cft:

Cement = 3 bags

Sand = 900 kg

Coarse aggregate = 1348 kg

Water = 75 liters

What is foundation ? purposes of Foundation and factor effects on Foundation

2019-12-01T09:00:00.000+05:00

Many structures like dams, bridges, buildings, roads, etc are created by civil engineers to serve our numerous necessities. Structures apply load on soil on which they rest.
This part of the structure is called sub-structure. Sub-structure is usually called foundation. Thus structural elements that connect, bridges, buildings etc. to the ground are called foundations.
Foundation of any structure is incredibly necessary as a result of the safety and reliability of structure depends upon foundation.

“The lowest part of a structure which transfers a load of superstructure along with its own weight into the soil underneath without carrying shear failure or bearing capacity failure and excessive settlement is called foundation.”

The following are the main functions of the foundation:

• To distribute the load of the structure over a large bearing area to bring the intensity of loading within the safe bearing capacity.
• To load the bearing surface at a uniform rate ( prevent unequal settlement)
• To prevent the lateral movement ( caused by wind, water or earth quick)
• To increase the stability of the building as a whole.

Also Read Types Of Masonry Construction Based On Material

The requirement of a good foundation:

• Foundation should be located that it is able to resist any unexpected future influence which may adversely affect its performance.
• The foundation should be stale against any possible failure.
• The foundation should not settle or deflect.

Factor affecting the selection of foundation:

• Importance of the Building
• Life of the Structure
• Loads from superstructure
• Type of construction materials to be used.
• Water table level.
• Type of adjoining structure.
• Soil condition.
• Location of building

Whole circle bearing (WCB) and Quadrantal Bearing System (QBS) in Surveying

2019-11-29T22:08:00.000+05:00

The whole bearing system (WBS) and the quadrantal bearing system (QBS) are two bearings systems used in the compass survey. With a simple calculation, the WCB system can be converted to QBS.

The article briefly explains the different bearings used in the survey and classification of bearings (WCB and QB system).

Bearing and Angles:

You may measure a survey line in relation to another survey line or in relation to the meridian. The first method provides the line angle. The second one is giving the bearing The bearing can, therefore, be defined as the line's direction for the given meridian.

There are mainly three types of meridian:

True meridian
Magnetic meridian
Arbitrary meridian

1. True Meridian:

A line passes through a point, with a plane passing through the point and the north-south poles forming the true meridian.

In other words, it forms the line that passes through the true north and the south poles.

The true bearing of a given line is the horizontal angle made with the true meridian through one of the extremities of the line.

2. Magnetic Meridian

The magnetic meridian is the direction shown by a freely suspended and floating balanced magnetic needle. To determine the magnetic meridian, a magnetic compass can be used. For this purpose, the magnetic compass used must be free of other attractive forces.

The magnetic bearing of a given line is the horizontal angle that it makes with the magnetic meridian that is passing through one of the extremities of the line.

3. Arbitrary Meridian

In some situations during the survey, a convenient direction is set for a permanent or common mark or signal in the area. These are called arbitrary meridians which help determine the survey line's relative positions.

The horizontal angle made by a line with the arbitrary meridian passing through one of its extremities is called as an arbitrary bearing.

Whole Bearing and Quadrantal Bearing Systems:

A WCB bearing system measures an angle in the clockwise direction from the magnetic north or to the south.

hence, the bearing value varies between 0 degrees and 360 degrees. A WCB system graduates from a prismatic compass.

The Quadrantal Bearing or Reduced Bearing System (QB):

The bearing angle is measured in the QB system either from the north or from the south, whichever is nearer. In either clockwise or anti-clockwise, this can be measured Here it is necessary to mention the quadrant at which the line lies. The Q.B lines vary from 0 to 90 degrees.

Also Read What Is Leveling And Types Of Leveling? Surveying & Leveling

Quantity Of Cement And Sand Calculation In Mortar CFT

2019-11-28T18:03:00.002+05:00

A quantity of cement mortar is required for a building or structure to analyze the rate of brickwork and plaster or to estimate the masonry work. Cement mortar is used in different proportions, i.e. 1:1, 1:2, 1:3, 1:4, 1:6, 1:8 etc.

Calculation Of Quantity Of Cement Mortar In Brickwork And Plaster:

Let's assume that the volume of masonry work is 20cft. and we assume the ratio of mortar 1:4.

When we estimate the mortar quantity for any masonry work, we just get the wet volume of mortar.

Now we will see how to calculate the dry volume of mortar and then we will calculate the cement and sand quantity in 20cft.

Grains of sand in dry conditions include air voids. Therefore, by adding water to the dry sand, the sand volume will be reduced This happens because of the presence of air voids in particles of sand. The percentage of air void sand compressibility is between 20% and 27%.

Normally, when converting the wet volume into the dry volume, we take the highest percentage of air void compressibility of sand. That's 27% of it.

So when we calculate the dry volume of mortar, we just multiply the wet volume by 1.27.

Dry volume= 20 x 1.27 = 25.4 cft

So now we have the dry volume of mortar which is 25.4 Cft

Now we will calculate the quantity of sand and cement in 25.4 Cft.

first, we will calculate the sum of ratio and our mixing RATIO IS 1:4.

Sum of ratio= 1+4= 5

Also Read Quantity Of Cement And Sand Calculation In Mortar meter cube

The volume of cement will be calculated as:

(1 ÷ 5) x 25.4 = 5.08 cft

Since the volume of 1 bag of cement is 1.25 Cft, so the number of a bag of cement will be calculated as:

5.08 ÷ 1.25 = 4.064 bags

The volume of Sand will be calculated as:

(4 ÷ 5) x 25.4 = 20.32 cft

Quantity of cement in 20 Cft masonry mortar = 4.064 Bags say 4.5 or 5 bags

Quantity of cement in 20 Cft masonry mortar = 20.32 cft

Conclusion

To calculate the dry mortar volume, you simply need to estimate your work item's wet mortar volume and then multiply it by 1.27.

Once you get the required dry mortar volume the amount of cement and sand required for the mortar can be calculated based on the proportion of the mixture.

Quantity of Cement and Sand Calculation in Mortar m3

2019-11-27T15:08:00.000+05:00

Calculation of quantity of cement mortar in brickwork and plaster:

Let us assume that we use 1m3 of cement mortar for the calculation of cement mortar. The calculation method is:

1. Calculate the amount of dry material required for 1m3 cement mortar. Considering the voids in the sands we assume the material is consists of voids of 60%. That is, 1.6m3 of materials are needed for 1m3 of wet cement mortar.

2. Now, based on its proportions, we calculate the volume of materials used in cement mortar.

Let's say, the cement and sand ratio is 1:X, where X is the required sand volume.

Then, the volume of sand required for 1:X proportion of 1m3 cement mortar will be

3. The volume of cement will be calculated as:

Also Read Types Of Masonry Construction Based On Material

Since the volume of 1 bag of cement is 0.0347 m3, so the number of a bag of cement will be calculated as:

For cement mortar of 1:6, the quantity calculated will be as below:

Sand Quantity:

Quantity of cement (in bags):

The volume of cement =

There number of bags required = = 6.58 bags.

Next article= How to find cement and sand quantity in the mortar in Ft3

Types of Masonry Construction Based on Material

2019-11-26T22:42:00.000+05:00

A variety of materials may be used in masonry construction, combined with mortar of varying strength. Brick, stones cement, veneer, gabion, etc. are some of the common materials used.
Some of the important masonry construction based on the material used are briefly explained.

1. Brick Masonry Construction

The construction of brick masonry uses first-class burnt clay bricks. Third-class bricks are used in masonry for less important construction. Second-class bricks are best for plastered masonry construction due to lack of finish compared to first-class bricks.

The overall tensile strength of the brick masonry is lower, regardless of the brick class chosen. Overall performance depends on the size, position, and number of openings provided to the structure of the masonry.

2. Stone Masonry Construction

Stone, relative to any other, is the most durable solid, and weather-resistant construction material. These are less affected by wear and tear from day today. Masonry structures made of stone also last longer. It has a lifetime of between 300 and 1000 years plus years. It is widely used in masonry construction because it is numerous advantageous.

Stonemasonry has two main classifications:

Rubble Masonry
Ashlar Masonry

Rubble Masonry is again classified into:

Uncoursed or Coursed Random Rubble Masonry
Uncoursed or Coursed Square Masonry
Polygonal Rubble Masonry
Dry Rubble Masonry

Ashlar masonry is again classified into:

Ashlar Fine Masonry
Ashlar Block in Course
Ashlar Chamfered Masonry
Ashlar Rough Tooled Masonry
Rock or Quarry Faced Masonry

also read Quantity Of Cement And Sand Calculation In Mortar M3

3. Concrete Masonry Construction

In the construction of concrete masonry, the blocks of concrete are pressed on top of others similar to the construction of brick masonry. This produces a turbulent formation The scale of concrete blocks is smaller than that of bricks, so it takes less time to lay concrete blocks.

It is, therefore, popular to build concrete blocks as it is affordable and gain high fire resistance. The concrete blocks of masonery come in different sizes, forms, and special designs, making it a flexible medium for building. It is commonly used in factories, universities, and residential building construction.

4. Veneer Masonry Construction

This construction of masonry is a style that is mainly used for remodeling and interior finishing. It gives the appearance of a more economical and isolated stone or brick wall. It is possible to place veneer maçonnery units on the existing concrete wall, giving a better look.

5. Gabion Masonry Construction

Gabions are baskets made of zin-protected steel or galvanized steel, filled with broken stones of medium size. These gabions are working as one unit. This functions as preservation or as retention of walls. These units of masonry are in nature well-drained and flexible. As a result, they have high horizontal pressure resistance such as water floes, surface flow, frost damage and floods. Commonly used gabions are in fact rectangular. The strength of gabions relies on the steel's corrosion resistance properties used in gabion baskets.

6. Composite Masonry Construction

Two or more types of building materials are used for the construction of a composite masonry structure. These masonry buildings are used to increase the building's appearance and to make use of available material resources with the utmost economy.

Bearing Capacity of Different Types of Soil

2019-11-25T12:44:00.000+05:00

Bearing capacity values of various soil types like clay, sand, gravel, rocks, etc.
Bearing capacity can be defined as ;

"The maximum load per unit area which the soil will resist safely without displacement."

Types of Soil	Bearing Capacity (Kg/m2)	Bearing Capacity (kN/m2)
Soft, wet clay or muddy clay	5000	50
Soft clay	10000	100
Fine, loose and dry sand	10000	100
Black cotton soil	15000	150
Moist clay and sand-clay Mixture	15000	150
Loose gravel	25000	250
Medium clay	25000	250
Medium, compact and dry sand	25000	250
Compact clay	45000	450
Compact sand	45000	450
Compact gravel	45000	450
Soft rocks	45000	450
Laminated rock such as sandstone & Limestone	165000	1650
Hard rocks such as granite, diorite, trap	330000	3300

Also Read What Is Soil? Formation And Types Of Soil?

The maximum load per unit area is the soil bearing strength. This is the total soil bearing capacity shown in the table. By dividing the ultimate soil bearing capacity by a safety factor, we obtain the maximum safe soil bearing capacity for foundation design

How to convert?

1 kg = 10 N, so, 1000 N = 100 kg = 1 kN. So, the value of column 1 is divided by 100 to obtain value in kN/m2

What is Soil? Formation and types of Soil?

2019-11-24T13:38:00.000+05:00

What is soil?

The term "Soil" has different meanings depending on the field of general professional consideration.
To an agriculturist, Soil is the material on the surface of the earth which grows and produces plant life.
To the Geologist, Soil is the substance in the relatively thin surface area within which there are roots.
To an engineer, Soil is an unconsolidated agglomerate of minerals found on or near the earth's surface with or without organic matter through which and on which engineers build structures.
It covers the entire thickness of the earth's crust that is accessible and feasible for practical use as foundation support or building material.
The behavior of soil as a foundation or building material is heavily influenced by the following:

Moisture content present in soil pores
The fluctuation of the groundwater table
Freezing and thawing phenomena
Presence of organic matter
History of the formation of soil
Seismicity of area

Mechanical or attractive forces bind the particles of the soil together.
The binding strength of the soil is very low compared to the rocks.
The type of soil will differ between clay and gravel and even between cobble and boulders.
The topsoil, normally two feet deep, contains organic matter and is generally considered unacceptable for use in civil engineering.

Formation of soil:

Soil is generally formed by rock decomposition or disintegration (rock weathering) on or near the earth's surface through the action of many natural, physical, and chemical agents that often break them into smaller and smaller particles.

The weathering of rocks may be the following:

Physical/mechanical weathering
Chemical weathering

1.Physical/mechanical weathering:

It is the disintegration of rocks caused by changes in temperature, freezing and thawing, swelling, flowing water erosion, natural disasters (earthquake, land sliding, etc.) and animal activities including people.

Soils formed by physical weathering retain parent rock minerals.

Coarse-grained soils (gravels, sands and their mixtures) are the physical weathering products

2. Chemical weathering:

Weathering caused by oxidation, hydration, carbonation, desilication, and leaching of rock minerals is known as chemical weathering.

The common soils formed by chemical weathering are different types of clay and organic soils (peat, muck, hummus, etc.).

Types of Soil Based on Particle Size:

Types of soil based on engineering considerations depend on particle size. As the engineering properties of soil change with particle size change, different names are given for different particle size ranges. The range of particle size defined for each soil type varies among agencies.

clay:

Composed of fine particles with a size of less than 0.002 mm. Flaky in the form with a large area of the surface. Have a strong attraction of inter-particles and therefore have sufficient cohesion. Poor permeability is vulnerable to swelling and shrinking. Typically the color is brown.

silt:

Composed of particles between 0.002 and 0.06 mm in size. Have high capillarity and dry strength very low. The intermediate particle size between clay and sand, therefore, has sand and clay properties, i.e. it shows slight friction and friction as well. The silty soil color is mostly brown.

Sand:

Particle size from 0.06 to 2 mm, in shape, can be rounded to angular in color brown. No plasticity, high resistance in a confined environment and significant resistance to friction. angular particles have a high resistance to friction compared to rounded particles. It is extremely permeable and has low capillarity.

gravel:

The particle size ranges between 2 and 60 mm. Form good material for the foundation. Show high resistance to friction. Angular particles have a high resistance to friction compared to rounded particles. The gravel produced by rock crushing is angular in shape, while those taken from the riverbeds are sub-rounded to rounded.

Cobbles and Boulders:

Particles larger than gravel are commonly referred to as cobbles or boulders. Cobbles vary between 60 and 200 mm in length. Boulders are the material greater than 200 mm.

Soil types According to ASTM and AASHTO:

Difference between Tender and Contract Documents

2019-11-23T22:37:00.000+05:00

In order to understand the difference between tender documents and contract documents, we must first understand what they contain.

Tender Documents:

A tender is a written offer to contractors to conduct such specified works or to supply specified materials within a specified time period and in compliance with contract and contractual conditions between the contractor and the owner or department or party.

The tender documents contain the bill of quantities (BOQ), work specifications to be performed, time frame for completing the work, contract conditions and plans and drawings. On the payment of certain fees, these documents are given to the contractor. The contractor who offers the lowest or appropriate rates for the works as a whole is offering the contract to do the work.

It's a document pre-bidding. This document mainly describes four issues, i.e. 1 Contractor Eligibility Criteria, 2 Project Timeline 3 Contract Working Procedure and 4 Quantity Material Specification(BOQ).

In order to obtain tender papers, there are also some limitations. In some cases, only the tender document is available to the contractor who is eligible.

Once the rate is quoted by the contractor in BOQ, it is sealed in cover and submitted to Tender Inviting Authority Panel. At the date of tender opening, the panel will unseal the cover and start to name L1, L2 & L3 respectively to the contractor, who quoted the lowest or appropriate value of three members. Then the negotiation process will take place, the contractor who comes for the lower price to him the tender will be awarded.

Contract Documents:

Contract documents are the arrangement between the owner or the party or agency and the contractor to conduct the works as stated in the tender documents on the rates quoted by the contractor in compliance with the contract conditions.

It is a Post – Bidding Document. This document is a total of an agreement. Once the bidding is over the contractor and client will undergo an agreement that the Project will be completed in scheduled time, with the same specification and working procedure as mentioned in the Tender document. If the project is delayed due to the contractor, then the penalty will cover some percent of the total project cost. This agreement is documented as a Contract Document.

Tender and Contract Documents difference:

The difference to remember here is that tender contracts are given to as many suppliers as possible to receive the lowest offers for the stated work, whereas contract agreements are only signed with the contractor with the appropriate or lowest bid or rates and technical skils.

While the tender documents include the contract terms and all the information for the stated work, in terms of content, there is not much difference between the two. But it is not possible to send tender documents as Letter of Acceptance (LOA) since these are two different types of documents. While a tender document can not bind the contractor to do the work, the contractor is bound by a contract document to complete the work as per the contract.

Simple Example for understanding the difference between tender documents and contract documents:

When you are selected for a job in a company you are offered an offer letter to join the company. But getting selected in a company does not mean that you join the same company, you may have other offer letters as well. But when you sign the letter of acceptance (LOA) for the job, you are bound to join the company. So, here offer letter from the company is a tender document and LOA is the contract document.

Sieve Analysis of Coarse Aggregate ASTM : Explanation and Procedure of TEST Step by Step

2019-11-23T17:16:00.000+05:00

TO FIND THE GRADATION OF COARSE AGGREGATE BY SIEVE ANALYSIS (ASTM C136-05).

THEORY & IMPORTANCE:

This experiment is conducted to find and check coarse aggregate gradation i.e. crush. The main bulky component of the concrete is crush; it is used together with its strength-giving properties to increase the volume of the concrete. it calculates its fineness module to find the water ratio to be used, along with the value of the specific crush gravity and its maximum grain size.

The maximum size of the coarse aggregate will be calculated from the modulus fineness table in this experiment. For example, if its maximum size is 3⁄4 inches, it means that all grain size is less than 3⁄4 inches. This can also be expressed by writing it as a crush: 3⁄4 inch down.

APPARATUS DETAILS:

For this gradation, the sieve used is 1 1⁄2 in, 1 in, 3⁄4 in, 1⁄2 in, 3/8 in, and #4 sieve. The distinction is that #4 sieve means that in one linear inch of the sieve there are four holes, while 1 1⁄2 inch sieve means the one side dimension of the sieve hole is 1 1⁄2 inches (not that in one linear inch of the sieve there are one and a half inches). The sieves are stacked with their lengths in ascending order. The crushed sample here is 3000 g.

APPARATUS:

Sieve Apparatus or sieve set.
Electronic Balance.
Brittle brush.
Empty plate.

Electronic Scale

Sieve Set & shaker

MATERIAL:

Sample of Coarse aggregate

PROCEDURE:

Ø Took the digital balance and set the scale reading to zero

Ø Took and measured the weight of pan.

Ø Put some crush in the pan and measure 3000 grams of crush with the help of electronic balance.

Ø Put the crush in a sieve of 1. 5 inches and began shaking until no more seeds could escape it readily. Using the electronic balance, measured the weight retained on the sieve and noted it in the table.

Ø Some stone had fallen out of the reduced sieve placed it in it and begins to shake the sieve for sufficient time. Noted the sieves read of the retained weight.

Ø Similarly, placed the entire remaining crush in the below sieve and began shaking for enough moment and noticed the weight retained in all the sieves.

Ø Calculated the percentage of each sieve's weight retained.

Ø The percentage of the weight that had passed through each sieve was found in the next phase. The complete quantity entered will be 3000 grams for 1.5 inch sieve.

Ø But it won't be the same for the 1 inch sieve because the upper sieve had retained some weight, so the proportion of the passing was calculated relative to the quantity that enters that sieve.

Ø For a sieve of 3⁄4 inches, the total quantity entering the sieve will be less the value for the upper sieve, similarly, for other sieves, the same method should be used to calculate the percentage of the passed weight

Ø The cumulative proportion was calculated in the next column. This was the weight proportion that would be retained if the crush were placed directly on the sieve. It will be the same as it was for 1. 5 inch sieve, but for 1-inch sieve, it would be the sum of the proportion retained by 1. 5 inch sieve plus the one retained. Similarly, the cumulative proportion was calculated for other sieves, this was denoted by a1, a2, a3, etc

Ø Then at the end to find the crush's fineness module add each sieve's cumulative proportion and divide it by 100.

Observations and Calculations:

Total weight of natural coarse aggregate = 3kg.

Sieve No	Weight Retained on Sieve (kg)	Percentage of weight Retained (%)	Percentage Of weight Passed (%)	Cumulative Percentage of Retained (%)
1 in	0	0	100	0
3/4 in	0.3594	11.98	88.02	11.98
1/2 in	1.1526	38.42	49.6	50.40
3/8 in	0.9732	32.44	12.16	82.84
#4	0.489	16.30	0.86	99.14

Finess modulus formula= a1+a2+a3+a4+a5 / 100

(Note:- a is the Cumulative Percentage of Retained (%) )

Finess modulus= 244.36/100=2.44

What is Leveling and types of Leveling? Surveying & Leveling

2019-11-22T15:30:00.000+05:00

What Is Leveling?

Leveling is a civil engineering survey branch of measuring levels at different points with respect to a fixed point such as building elevation one-point height from the surface, etc.

Types of Leveling in Surveying.

Direct leveling
Trigonometric leveling
Barometric leveling
Stadia leveling

Direct Leveling:

It is the most commonly used leveling process. Measurements are directly observed from the leveling instrument in this process.

Direct leveling is divided into different forms on the basis of observation points and instrument positions as follows:

Simple leveling

Differential leveling

Fly leveling

Profile leveling

Precise leveling

Reciprocal leveling

Simple leveling:

It is a simple and fundamental method of leveling in which the instrument of leveling is positioned between the points to be found in elevation. At that point, leveling rods are placed and viewed by means of a leveling instrument. Only when the points are nearer to each other without any barriers is it done.

Differential leveling:

When the distance between two points is greater, differential leveling is performed. The number of interstations is located in this process and the instrument is shifted to each station and the elevation of interstation points is observed. Finally, the difference is determined between the initial two points.

Fly leveling:

When the benchmark is very far from the workstation, fly leveling is performed. In such a case at the work station, a temporary benchmark is placed based on the original benchmark. It is used to evaluate approximate standard, even if it is not highly accurate.

Profile leveling:

Typically, profile leveling is adopted to identify points along a line such as a road, rail or river, etc. In this case, intermediate station readings are taken and each station's reduced level is found. From this alignment, the cross-section is drawn.

Precise leveling:

Precise leveling is similar to differential leveling, but higher precision is expected in this case. Serious analysis technique is conducted to achieve high precision. The accuracy is achieved by 1 mm per 1 km.

Reciprocal leveling:

If the leveling device can not be found between the inter-visible points, reciprocal leveling is carried out. In the case of lakes or streams, etc., in the case of mutual leveling, the instrument is placed closer to the first station and sighted to the second station.

Trigonometric Leveling:

It is called trigonometric leveling the leveling process in which the point elevation or the difference between points is determined from the observed horizontal distances and vertical angles in the field. Trigonometric relationships are used in this method to calculate a point elevation from an angle and horizontal range, so it is called trigonometric leveling. It is also referred to as indirect leveling.

Barometric Leveling:

A barometer is an instrument used to calculate at any altitude atmosphere. Thus, in this leveling method, atmospheric pressure is observed at two different points on the basis of which the vertical difference is determined between two points. It is a rough estimate and is rarely used.

Stadia Leveling:

It is a modified form of trigonometric leveling in which the principle of Tacheometer is used to calculate the point elevation. The line of sight is angled from the horizontal in this case. It is more accurate and suitable in hilly terrain for surveying.

What is Civil Engineering

2019-11-21T23:17:00.000+05:00

Engineering:

The use of science and math is engineering to model or construct things and buildings etc. People are called engineers who do engineering.

Civil engineering:

Civil engineering is the word for infrastructure design and construction work. Usually, it means large buildings such as bridges, reservoirs, homes, and tunnels. It also covers complicated networks such as networks for water, irrigation, and sewerage. It also involves building homes and dwellings.

Branches of civil engineering:

Civil Engineering has enormous scope and includes a wide range of sub-disciplines. Within this branch of engineering, there are different fields you can choose to pursue your career. The following are the branches of civil engineering.

1. Construction engineering:

Deals with planning, construction, and maintenance of structures such as houses, schools, plaza, bridges, and dams, etc.

2. Structural engineering:

Deals with Structural Analysis and Design of structures such as Framework of structures and design of structures to withstand environmental stresses and pressures and to remain secure, stable and secure during their use.

3. Geotechnical engineering:

Study of soil, foundations, bearing capacity, etc.

4. Transportation engineering:

Deals with planning, construction, and management of transportation facilities such as roads, etc.

5. Surveying:

Deals with surveying and leveling lands using different instruments, terrain mapping & contouring, etc specially used in road bridges and dams.

6. Water resources engineering:

Deals with design and construction of hydraulic structures like dams, canals, water distribution systems, etc.

7. Environmental Engineering:

Study of environment-friendly designs, sewage management, pollution, and their treatment.

8. Municipal engineering:

Deals with urban/city planning & management, township, etc.

9. Tunnel engineering:

Deals with planning, design, construction, safety, and maintenance of tunnels.

10. Coastal engineering:

Deals with coastal or marine structures like groynes (groins), embankments, etc.

11. Earthquake engineering:

Study of seismic forces, earth-quake resistant structures, etc.

Importance and Applications of civil engineering (in short)

With time, civil engineers are becoming increasingly important. They are now also responsible for the fire control systems and the installation of rapid-fire exit points in the buildings these construct. This will help minimize the loss of life in accidents involving fire. One of the oldest engineering professions is civil engineering. Classical structures such as the building of the Egyptian pyramids and the Roman road systems are based on principles of civil engineering. Environmental engineering is another very important aspect of civil engineering. In this case, civil engineers are concerned with different methods of purifying contaminated air, water, and soil. It is necessary to clean the polluted system, remove the waste and return the purified constituent to the natural system.
Civil engineers are also responsible for the design of high-quality transport systems such as roads, airports, bridges, marine ports, etc. A structural engineer must decide the best design of these structures and will look after the building process so that after completion the stability of these structures is guaranteed. These structures should also be satisfied for the public.

Civil Engineering

English Bond and Flemish Bond – Features & Difference

English Bond and Flemish Bond – Features & Difference

English Bond

Features of English Bond

Flemish Bond

1. Double Flemish Bond

Features of Double Flemish Bond

2. Single Flemish Bond

Difference between English and Flemish Bond

Types of Foundation

Classification of Foundation

Shallow foundation :

Deep foundation :

Types of shallow foundation:

Spread footing or open trench foundation:

Wall footing:

Masonry wall footing:

Concrete column footing:

Raft or Mate foundation:

STEPPED FOUNDATION :

Strap footing :

Types of deep foundation:

pile foundation well foundation

Pile foundation :

Types of Pile Foundation

Well foundation:

How to calculate cement sand and aggregate quantity in concrete

Quantity Of Cement And Sand Calculation In Mortar CFT )

Calculation

Quantity of material in 30 cft:

What is foundation ? purposes of Foundation and factor effects on Foundation

The following are the main functions of the foundation:

The requirement of a good foundation:

Factor affecting the selection of foundation:

Whole circle bearing (WCB) and Quadrantal Bearing System (QBS) in Surveying

Bearing and Angles:

1. True Meridian:

2. Magnetic Meridian

3. Arbitrary Meridian

Whole Bearing and Quadrantal Bearing Systems:

The Quadrantal Bearing or Reduced Bearing System (QB):

Quantity Of Cement And Sand Calculation In Mortar CFT

Calculation Of Quantity Of Cement Mortar In Brickwork And Plaster:

Conclusion

Quantity of Cement and Sand Calculation in Mortar m3

Calculation of quantity of cement mortar in brickwork and plaster:

Types of Masonry Construction Based on Material

1. Brick Masonry Construction

2. Stone Masonry Construction

3. Concrete Masonry Construction

4. Veneer Masonry Construction

5. Gabion Masonry Construction

6. Composite Masonry Construction

Bearing Capacity of Different Types of Soil

How to convert?

What is Soil? Formation and types of Soil?

What is soil?

Formation of soil:

1.Physical/mechanical weathering:

2. Chemical weathering:

Types of Soil Based on Particle Size:

clay:

silt:

Sand:

gravel:

Cobbles and Boulders:

Soil types According to ASTM and AASHTO:

Difference between Tender and Contract Documents

Contract Documents:

Tender and Contract Documents difference:

Simple Example for understanding the difference between tender documents and contract documents:

Sieve Analysis of Coarse Aggregate ASTM : Explanation and Procedure of TEST Step by Step

APPARATUS DETAILS:

APPARATUS:

MATERIAL:

PROCEDURE:

Observations and Calculations:

What is Leveling and types of Leveling? Surveying & Leveling

What Is Leveling?

pile foundation

well foundation