Civil engineering study materials | Highway engineering | Structural elements of buildings

Classification of rocks

2020-02-23T11:16:00.000+05:30

Classification of rocks

According to wikipedia, a rock is any naturally occurring solid mass or aggregate of minerals or mineraloid matter. It is categorized by the minerals included, its chemical composition and the way in which it is formed.

The building stone are classified in three way : -

1) Geological classification of rocks

a) Igneous Rocks

All those rocks of the earth that have been formed by the natural process of cooling and solidification from hot and molten material (magma) are called igneous rocks. If magma solidifies on the surface of the earth basalt and traps are formed. If however the magma solidifies before reaching surface of earth, it forms granite.

b) Sedimentary Rocks

These rocks are formed by the deposition of product of weathering on the pre existing rocks. All the products of weathering are ultimately carried away from their place of origin by the agent of transport such agent are wind, frost etc. The consolidation of the above product take place under pressure by heat or by chemical agent acting as a natural cement, limestone, sandstone belong to this group.

c) Metamorphic Rocks

These are originally either igneous or sedimentary that have undergone considerable changes in their shape, structure and sometimes even in their mineral composition. Under the influence of the agent of metamorphism that is heat and pressure. Quartz, marble, slat are the example of metamorphic rocks

2) Chemical classification of rocks

a) Siliceous Rocks

These rocks have silica as their main component. They are hard, durable and not easily affected by weathering agent. Granite and quarsite are the examples of siliceous rocks.

b) Argillaceous Rocks

These rocks have Alumina clay as their main component. Although these rocks are dense, compact and hard. They are brittle and cannot stand with shocks. For examples, slate and laterite are the example of such rocks.

c) Calcareous Rocks

These rocks have calcium carbonate as their main component. Limestone, marble etc are the example of calcareous rocks.

3) Physical classification of rocks

a) Stratified Rocks

These rocks causes possess planes of stratification or cleavage and such rocks can easily split up along these planes. For example sand stone, limestone and slate etc.

b) Unstratified Rocks

These rocks occur in huge masses without showing any layered structure in them. It cannot be easily split into thin layers. For example Marble and Granite.

c) Foliated Rocks

These rocks have a tendency to be split up in a definite direction only. Foliated structure is very common in case of metamorphic rocks.

Classification of bricks as per BIS

2020-02-23T10:55:00.000+05:30

Classification of bricks as per BIS

As per BIS ( Bureau of Indian Standard ) the bricks are broadly classified into two categories: -

1) Sun - dried or unburnt bricks or Kaccha bricks

2) Burnt bricks or Pakka bricks

Classification of bricks

Burnt bricks are further classified as :-

a) First class bricks

b) Second class bricks

c) Third class bricks

d) Over burnt bricks or jhama

Characteristic of first class bricks

It should be well burnt raddish in colour having surface and perfectly rectangular in shape.
When two bricks are struck with each other a ringing metallic sound is produced.
Its compressive strength shall not be less than 140 kg per centimetre square.
It should not absorb water more than 15% of its weight when immersed in water for 24 hours.
Bricks should be free from cracks and other flaws.
A broken surface shows a uniform compact texture.

Uses

Excellent for all types of construction.
It is used in face work of structures not to be plastered but only pointed.
It is also suitable for flooring.

Characteristics of second class bricks

It should be well burnt, even slight burning is expected.
Metallic running sound is produced when to break system with each other.
Its shape with rectangular but slight irregularity is permitted. Surface may be slightly uneven.
Its compressive strength shall not be less than 70 kg per centimetre square.
Its should not absorb water more than 20% of its weight when immersed in water for 24 hours.
Broken surface shows uniform compact texture.

Uses

It is used for exterior work when plastering is to be done.
It is used for interior work this bricks me not be used for flooring.

Characteristic of third class bricks

These are poorly and unevenly under burnt.
These are soft and yellow in colour.
They produced a dull sound when struck with each other.
These bricks have compressive strength between 35 to 70 kg per centimetre square.
These bricks absorb water more than 25% when immersed in water for 24 hours.

Uses

It is used mostly in ordinary or temporary type of construction and dry condition.

Characteristic of over burnt bricks

These are irregular in shape and dark in colour which is due to over burning.
These are quite strong in compressive strength or crushing strength generally above 150 kg per centimeter square and low in porosity and absorption.

Uses

Despite their good strength over burnt bricks are unfit for use in building construction. This is because of their distorted shape and irregular size.
They are very commonly used in broken form( ballast ), in road construction, foundation and floor as a coarse aggregate.

Remedies for DPC

2020-02-12T10:14:00.000+05:30

Remedies for DPC

We have already discussed about DPC, causes and it effects.

Remedies to damp wall may be temporary or permanent according to the existence. Treatment to remove dampness would be different for internal and external wall.

Temporary remedies for internal wall

Application of bituminous painting

The affected wall is to be cleaned, allowed to be dried and then a coat of hot bitumen applying uniformly. However if there is a difficulty in applying hot bitumen, bituminous compound emulsion are available in the market which may be applied cold with brush.

Painting with waterproofing solution

Either commercially available such solution prepared solution as described letter may be applied as described after cleaning the surface.

Applying cement wash

In this method, cement and water mix in thin consistency with admixture of adhesive gum may be applied 1 or 2 coat after cleaning the surface.

Temporary remedies for external wall

Coating with linseed oil

Coating with boil linseed oil or commercially available linseed oil may be boiled and applied hot with brush after cleaning the surface.

Sylvester's process

Applying alternate coats of soap and alum solution to the wall where they will sink into the pores just below the surface. The first coat is to be applied after cleaning the surface. Subsequent coats to be applied after the previous has dried up.

Painting paraffin

Paraffin oil may be painted over the affected surface after cleaning the surfaces.

Permanent remedies

Before selecting the method for permanent remedy against dampness in wall one has to investigate the cause of dampness.

Dampness due to leakage from the roof
Stop the roof leakage.

Vegetation

Removal of the vegetation including of the vegetation including of uprooting and applying chemical solutions so that growth may not occur.

Earth banking

Bank, slopping ground etc the space around the building need be dressed to avoid spacing of water on the walls.

Cavities, hole etc.

Detect the exact spot open the space and fill the cavity with concrete.

Defective window sill

These are to be corrected.

Dampness in hollow wall

The main purpose of constructing hollow wall is defeated the outer leaf of a wall non-load bearing and may be open partially for removing the dropped mortar and cleaning. Further, the weep holes may be provided below horizontal damp proof course and air bricks may be provided at suitable places for ventilation.

Dampness, causes and its effect

2020-02-08T10:18:00.000+05:30

Dampness, causes and its effect

Dampness

Water is the most essential element required in the construction of a building whereas water or moisture is the most harmful element for causing damage to a building. Absorption of water by the materials (bricks, mortar, stone and concrete) is one of the chief cause of dampness.
According to Wikipedia, Structural dampness is the presence of unwanted moisture in the structure of a building, either the result of intrusion from outside or condensation from within the structure.

Causes of dampness

Porous bricks used in the construction is a permanent source of dampness in wall as attract moisture if there is no DPC of good quality.
Bad material used in construction are also the source of dampness.
The another source of moisture is the depletion of damp proof course.
Motor joint not set properly and uniformly are the source of attraction of moisture.
Leaking of water supply pipe allowing water to enter the walls.
Defective roof leakage is the major source of water entering the walls and make it damp.
Growth of vegetation in the wall indicates presence of moisture or water without which it could not grow.
Construction of earthen bank by the side of a building.
Presence of salt in the plaster is indicate the presence of dampness.

Effect of dampness

Unhygienic condition inside the building of the different materials due to disintegration of materials like bricks, stone, timber etc.
Effluorescence.
Damage of furniture.
Corrosion of metal.
Plastic getting soft and crumbling.
Damage of electric installation and short circuiting.
Deterioration of floor covering infestation of termite.
Flaking, blistering and bleaching of paint.

Concrete and its type

2020-02-07T09:42:00.000+05:30

Concrete in fresh state

Concrete and its type

Concrete may be defined as a composite mixture of binding material like cement or lime generally hydraulic lime, fine aggregate (course sand) and coarse aggregate (generally crushed stone or gravel) in definite proportion along the water. Freshly prepared concrete till it has not yet set is called wet or green concrete. When it has throughly sat and fully hardened it is called set concrete or just concrete.

Qualities of good concrete

It has high compressive strength.
It is free from corrosion and their is no applicable effect of atmospheric agents on it.
It hardens with age (time) and the process of hardening continuous for a long time after the concrete has to become a sufficient strain.
It is quiet strong in compression but weak in tension. As such it is saftely used in the construction of load carry structure like piers and abutment of bridge, column etc. In case of member subjected to tensile stress it has to be rain frost with steel bar.
The density of concrete is very high it with 3000 kg per metre cube.
It should be easily workable.
It form hard surface capable of resisting abrasion.
It should be able to withstand the action of chemical salts.
It should be strong, desirable, dense, workable and being able to resist wear and tear.

Plain Cement Concrete

It is defined as a composite mixture of cement, sand ( generally course sand) crushed stone or gravel in definite proportion along with water. As per IS : 456 - 2001 Concrete is designated in 7 grades as M10, M15, M20, M25, M30, M35, M40. The letter M refers to mix and the number indicate the specified characteristic compressive strength of that mix at 28 days of curing in N/mm2 (Newton per mm square).

Lean Concrete

Lean Concrete is a term used to describe low grade concrete. It does not contain many of high density rock material that regular concrete does. Lean concrete often consist of reclaimed concrete material, low cement contain fly ash and discarded sand. It is cheaper alternative to regular concrete.
The main function of lean concrete is to provide the uniform surface foundation and to prevent the direct contact of foundation from the soil. It is also used to fill abundant wells and cavities.

Reinforced Cement Concrete

RCC is very strong in compression but very weak in tension and shear. In the construction of those members that are subject to tension or shear, Steel bars in various forms is embedded (reinforced) in those member. This concrete in which Steel bars have been embedded to handle it take a tension or shear stress safely is known as Reinforced Cement Concrete and is designated simply as RCC. It is extensively used in construction of all type of buildings, bridges arches, tanks massive dams and retaining walls.

Classification of roads

2020-02-01T10:01:00.000+05:30

Classification of roads

The road can be divided into various categories depending on different factors such as traffic volume, type of traffic, purpose of road, importance, design speed, long or short distance traffic, horizontal and vertical alignment, etc.

Rural Road

According to the third road development plan, the rural road are classified into three parts :-

a) Primary System - It consists of Expressway and National Highway.
b) Secondary System - It consists of State Highway and Major District

Road.
c) Tertiary System - It consists of Other District Road and Village
Road.

Urban Road

The system of roads existing in urban areas is called Urban Road. They are divided into following types :-

a) Arterial Road

b) Sub Arterial Road

c) Collector Streets

d) Local Streets

Urban Road

Expressway

In this type, road has superior facility and design specification. These are having minimum four lane or more and the owner of this Highway may be State or Central government depending upon the location and category.

For example, Yamuna Expressway and Bombay to Pune Expressway.

National Highway

National Highway are the important Highway of country connecting major parts, capital of States, large industrial and tourist Centre. They also connect the highway of neighbouring countries and are required for the strategic movement of army. These roads are constructed and maintained by National Highway Authority of India. They are assigned by specific number. For examples, the National Highway from Delhi to Amritsar by Ambala is named NH1 and GT road from Kolkata to Amritsar is named NH 91. The total length of National Highway in India is around 60,000 km which is only about two percent of the total road length of the country but it carried about 40% of the traffic.

State Highway

These are the Arterial Road of the State. They connect major city in the State, District headquarter and to the National Highway of the adjacent State. These are funded by respective State Government. The total length of State Highway is about 1,40,000 km.

Major District Road

These are important roads within the District connecting market and production centres with each other and with the main Highway. They have lower speed unit as compared to NH and SH. The total length of major district road in India is about 4,20,000 km.

Other District Road

These roads serve rural areas of production and provide them access to market centres, block headquarter and Major District Roads.

Village Road

These roads connect villages with each other and to the other district roads. The total length of the village roads in India is around 26,50,000 km.

Arterial Roads

The system of roads provide the basic network for traffic flow. These roads may be used for travelling between urban areas between Central business district and outline residential
areas.

Sub Arterial Road

They are functionally similar to the road but having low traffic volume. They are generally 0.5 km apart in Central business district and 3 to 5 km apart in the Suburban.

Collector Street

Their purpose is to collect traffic from residential areas through local streets upto Sub Arterial and Arterial roads.

Local Street

The local street are provided space to facilitate movement of traffic from residential areas to collecting street. Moreover the traffic volume in local street is lowest as compared to the other category of roads.

Object of plastering and its requirement

2020-01-31T12:08:00.000+05:30

Object of plastering and its requirement

Plastering

Plastering is the process of covering of rough surface of walls, columns, ceiling and other building components within coat of plastic motor to form a smooth durable surface. The coating of plastic material that is motor is termed as plaster plaster on external exposed surface is known as rendering.

Object of Plastering

Plastering is done to achieve the following objects : -

To protect the external surface against penetratration of rainwater and other atmospheric agencies.
To give a smooth surface in which dust and dirts cannot lodge.
To give a creative effect.
To protect surface against termite to conceal inferior material or defective workmanship.
To give aesthetic views.

Requirement of Good Plaster

The Plaster material should fulfill the following requirements : -

It should be hard and durable.
It should possess good workability.
It should be possible to apply it during all weather conditions.
It should be cheap.
It should effectively check the penetration of moisture.
It should adhered to the background and should remain adhered during all variation is seasons and atmospheric conditions.

According to the use of the Plaster, we can classified into following categories : -

Cement plaster
Smooth Cast plaster
Rough Cast plaster
Pebble Desh plaster
Scrapped Finish
Textured Finish

Classifications of Bridge as per Engineers

2020-01-26T12:47:00.000+05:30

Classifications of Bridge as per Engineers

Bridge is a structure providing passage over an obstacle without closing the way beneath. The passage may be for a road, pedestrians, railways etc. The obstacles may be a river road, railway etc.

CLASSIFICATION OF BRIDGE

Bridge can classified into various types according to

Purpose

Highway bridge
Railway bridge
Foot bridge
Aqueduct
Viaduct

Material used for construction

Timber bridge

Masonry bridge
Steel bridge
RCC bridge
Prestressed concrete Bridge

Life

Temporary bridge
Permanent bridge

Relative position of floor

Deck bridge

Semi - through bridge

Through bridge

Type of Superstructure

Arch type bridge

Girder type bridge

Truss bridge

Suspension bridge

Alignment

Straight bridge

Skew bridge

Position of High Flood Level

Submersible Bridge

Non - submersible Bridge

Slab bridges
Slab bridges are suitable for span up to 10 metre. In this type of bridge a simple slab of uniform thickness is laid over abutment. It is used for small culverts and bridges.

Rigid Frame Bridge
This type of bridge is suitable for span upto 20 m and where more clearance is required below the bridge. In this type of construction horizontal deck slab is made monolithic with the vertical abandonment wall.

Balanced Cantilever Bridge
It is suitable for span in the range of about 35 to 60 m. In this type of bridge, the slab carrying the bridge floor is simply supported over balanced cantilevers.

Barrel Arch Bridge
Barrel arch bridges are suitable for span upto 70 and for medium traffic load where side banks are firm to resist the horizontal thrust of the earth. Front and back walls are provided along the sides of the arches and the space between them is filled with soil or sand.

T - Beam and Slab Bridges
This type of bridge is suitable for moderate span and where traffic is heavy but causes no sudden impact of the bridge in T - beam and slab bridge, simply supported over abutments and piers.

Railway and it components

2020-01-23T12:58:00.001+05:30

Railway and it components

Railway Engineering is the branch of transportation engineering where latest technology is used for the development, design, construction and maintenance of railway tracks for the safe, efficient and economical movement of rail traffic which include both passenger and goods train.

Components of railway track

Components of Railway Track

Gauge

Gauge is the distance between the inner edges of a pair of rails. There are three types of gauges used in Indian Railway System -

Narrow gauge - 762 mm
Metre gauge - 1000 mm
Broad gauge - 1676 mm
98% of railway track is using Broad Gauge System.

Rail

Rail is the main component of railway track and provide hard and smooth surface for running of trains. The rail section is of three types double headed, bull headed and flat footed. The rail section is generally made of high carbon steel having high tensile strength. The Broad gauge rail section is of three types :- According to weight 60 kg, 52 kg and 19 pounds
The length of the single rail in Broad gauge system is 13 metre.

Rail joints

Various rails are joined together to form a smooth railway tracks. There are two ways of joining the rails that is by welding or by using fish plates and fish bolts. Fish plates are metal elements which are bolted to the end of rails using fish bolts.

Rail fastening

Rail fastening are fitting which are used to fix rails to sleepers. Spikes and clips are used for this purpose. A rail spikes a big nail that has an offset head and it is used to clamp the base plate with the sleeper. There are three types of Spike i.e., is dog spikes, round spikes, and screw spikes.

Clips

Clips are used in concrete sleepers to connect the rail with the sleeper. They are composed of silicon steel rod 20.6 mm in diameter and each sleeper required 4 clips.

Sleeper

Sleepers are the member placed under the rails in transverse direction to transmit the load from the railway wagon and coaches through the rails to the formation.

Function of sleeper

To support the rails firmly specially on turn out and crossing.
To hold the rail in place at a given gauge and at inward slope of 1 in 20.
To transfer and distribute the load to the stone ballast or concrete block.
To provide an elastic medium between the rails and ballast and to absorb the vibration.
To maintain the alignment and superelevation of the track.
To provide stability and stiffness to track.

Foundation and its type

2020-01-22T10:55:00.001+05:30

Foundation

Foundation and its type

Foundation is the lowest part of the structure which provide a base or superstructure in a proper way. The soil which is located immediately below the base of the foundation is called subsoil while the lower portion of the foundation which is direct in contact with the sub soil is called Footing.

Function of foundation

The basic function of foundation is to translate the dead load, superimposed load or live load and wind load from a building to the soil on which the building rest in such a way that settlement are permissible limit without considering cracks in superstructure
soil does not fail when loads are transmitted to the subsoil.
It settles if settlement is slight and uniform throughout. No damage will be caused to the building.

Classification of foundation

Foundation may be broadly classified under two heads -
1) Shallow Foundation
2) Deep Foundation

Shallow Foundation

If the depth of Foundation is less than its breadth or width then it is called shallow foundation. From the point of view of design, foundation of the following types: -
a) spread footing
b) combined footing
c) strap footing
d) mat or raft footing

Spread Footing
Spread footing are those which spread the superimpose load of the Wall or column over a larger area

Combined Footing
A spread footing which support two a more column is termed as combined footing. The combined footing may be of the following kinds : -
Rectangular footing
Trapezoidal footing
Combined footing for column will be rectangular in shape if they carry equal loads. The design of rigid rectangular combined footing should be done in such a way that CG of column load coincide with the centroid of the footing area. If the column carry unequal load the footing is of trapezoidal shape.

Strap Footing
If independent footing of two columns are collected by Beam then it is called a strap footing. A strap footing may be used where distance between the column is so large.

Mat Foundation or Raft Foundation
A combined footing that covers the entire area beneath the structure and support all the walls and columns when the allowable soil pressure is low or the building loads are heavy, the use of spread footing good cover more than one half of the area. carry equal Lords the design of rigid rectangular combined footing should be done in such a way that CG of column load side with the centroid of the footing area if the column carry unequal load the footing is of trapezoidal shape.

Deep Foundation

If the depth of the foundation is more than its breadth or width then it is called Deep Foundation.

Deep Foundation may be of the following types : -

a) Deep strip, rectangular and square footing

b) Pile foundation

c) Pier foundation

d) Well foundation

Note - We will discuss deep foundation in our next post.

Sight distances | SSD and OSD

2020-01-18T11:38:00.000+05:30

SIGHT DISTANCES | SSD and OSD
It is defined as the length of the road visible to the driver a head of him at any time instant. It can be divided into various types such as : -

Stopping Sight Distance

The minimum sight distance available on highway at any spot so that the driver is able to stop his vehicle when he sees any obstruction without causing any accident or collision. As per IRC guidelines, the height of the eye level of the driver above the payment surface must be 1.2 metre and height of the object must be 0.15 metre.
The stopping sight distance depend upon the following factors like reaction time, speed of the vehicle, efficiency of brakes and frictional resistance. The reaction time depends upon PIEV theory where P stand for perception time, I stand for intellection time, E stand for emotion time and V stand for violation time.
The speeds is also is an important factor for deciding SSD. More
is the speed more will be the SSD.
Braking efficiency is also important and idealy. It should be 100%.
Therefore, the total stopping sight distance is : -

SSD = vt + {v^2/ 2g (f +n )}

v = design speed in metre per second ( m/s)

t= reaction time (2.5 sec)

f = design coefficient of friction (0.35 0.4)

n = slope or gradient

Overtaking Sight Distance

It is the minimum distance provided in the highway design so that the driver of the vehicle moving with the design speed which is able to overtake a slow moving vehicle ahead without possibilities of accidents with another vehicle coming from opposite direction.

As per IRC norms the height of the high level of the driver is considered to be 1.2 m above the road level and height of the top of the object is also same i.e., 1.2 m.

OSD = v't + v'T +2S + v.T

Division of hydrological cycle

2020-01-14T11:31:00.000+05:30

Division of Hydrological Cycle

Hydrological cycle

It is the process of transfer of moisture from the atmosphere to the earth in the form of precipitation conveying of precipitated water by streams, rivers to ocean, seas and lakes and evaporation of water back to the atmosphere.

It consist of the following process : -

1) Precipitation

It may be defined as of moisture from the atmosphere to the surface in any form, precipitation may be in two forms :
(a) liquid precipitation and
(b) frozen precipitation

(a) Liquid Precipitation

This type of precipitation is further divided into three types.

a) Rain:

When the size of drops is more than 0.5 mm. The upper size of water drops generally 6.25 mm as drops greater than this size tends to break up as they fall through air.

b) Drizzle:

When the size of the water droplets is under 0.5 mm and its intensity is less than 0.01 mm/hour.

c) Sleet:

They are frozen rain drops coded to ice stage by falling through air at sub freezing temperature.

(b) Frozen Precipitation

(a) Snow: Precipitate in the form of ice crystals resulting from sublimation i.e.water vapour changes directly to ice.
(b) Hail: It is a lamp or bulk of ice over 5 mm dia formed by alternate freezing or melting as they are carried up and down in turbulent air currents.

2) Run Off

It is that part of precipitation which It is that part of precipitation which is available on earth surface after loss to the atmosphere.

Surface runoff:

It is that part of precipitation which flows on the earth surface after loss to the atmosphere and loss to the ground.

Sub surface runoff :

It is that portion of precipitation which flows below the surface of the earth through the interconnecting voids of the soil as far as the slope is available or it joins nearby ponds, stream.

Ground water flow :

It is that portion of precipitation which after infiltration percolates down and joins the groundwater table.

3) Interception

It is that portion of precipitation which is being retained by the trees plants and bushes available on the earth surface.

4) Surface Detention

It is that portion of precipitation which is being detained in the natural depression available on the earth surface.

5) Evaporation and Transpiration

Water from the surface of oceans, rivers, lakes and moist soil. The vapours are carried over the land by air in the form of clouds. Transpiration in the process of water being lost from the leaves of plant.

Types of railways and its necessity

2020-01-13T09:31:00.001+05:30

Types of railways and its necessity

Railways are the most developed means of transportation in India. It has developed the national production, social and industrial development and the economic status of the country.

● Railways help in the mass migration of the population.
● Railways provide a convenient and safe means of transport for the country.
● Railways provide employment of millions of people and thus help in solving the unemployment problem.
● Railways also help in maintaining the law and order in the country.
● Railways help to increase the national wealth and value increase due to industrial development.
● Speedy distribution of natural resources and agricultural products is achieved through railways.

Systems of Railways

Surface Railways

Surface railways are railways provided over the ground surface. In this system the rails are laid on investment foreign cutting and is the most extensively used throughout the world because of its initial cost of construction.

Underground Railways

Underground or low level railways provided just below the ground level. Tunnels are also constructed for carrying tracks in the system of railways. Only electrically operated engines are used in underground railways. These railways are suitable in congested urban areas where the traffic intensity on roads is heavy. The metro rail in Kolkata is an example of underground railways.

Tube Railways

This system of railways are constructed underground at a depth of 18 m or more. This is called tube railways as the tunnel carrying the track is like a tube. The purpose of providing tube railways is to avoid interference of the tracks with underground gas sewage and oil pipe well as water.

Elevated Railways

Elevated railways are railways provided at elevated portion above the ground surface. In this system of railways, the track is laid on the deck of continuous viaduct which is supported on pier or columns. Elevated railways a suitable in the heavily congested urban areas where the underground railways cannot be constructed. The Metro rail which is under construction in Delhi is a example of elevated railways.

Curves and its types (Horizontal and Vertical curve)

2020-01-10T09:34:00.000+05:30

Curves and its types (Horizontal and Vertical curve)

Types of horizontal curves

1) Simple curve
2) Compound curve
3) Reverse curve
4) Transaction curve

Simple curve

It is a circular curve which consists of a single arc of uniform radius. This curve is expressed in terms of degree of the curve, which is the angle subtended at the centre by a chord of 30 metre length. This type of curve is suitable for large radius and for slow moving traffic.

Compound curve

This is a circular curve which is comprised of a series of two or more simple curve of different radii which turn in the same direction. This type of curve is used to avoid cutting through hard ŕocks, heavy cutting of filling etc.

Reverse curve

This is a circular curve consisting of two simple curve of same or different radii which turn in the opposite direction. These curves are suitable for highway lying in hilly regions.

Transition curve

It is the curve having a radius which decreases from infinity at the tangent point to a designed radius of the circular curve. This type of curve in generally introduced on highway between a straight and circular curve to provide ease and gradual change in direction of a road alignment.

Types of vertical curves

1) Summit curves
2) Valley curves

Summit curves

Summit curves are the vertical curves having their convexity upward. The centrifugal force will act upward against gravity when a fast moving vehicle travels along a summit curve and there will be no problem of discomfort to the passengers.

Valley curves

Valley curves are the vertical curves having their convexity downwards. At the valley curves centrifugal force acts downwards adding to the pressure on the suspensions in addition to the self weight of a vehicle moving on the curve.

Curves and its type

2020-01-09T09:41:00.001+05:30

Curves and its type

Curves are the geometrical arcs provided at the change in gradient for alignment of road.

Necessity of providing curves

To lay the road according to topography of the country.
To avoid costly land.
To avoid excessive cutting and filling.
To avoid certain important structures.
To make use of the existing Road bridges etc.
To provide access to the particular place.

Types of curve

1) Horizontal curve
2) Vertical curve

A horizontal curve is a curve in plane to provide change in direction to the central line of road. The minimum radius of horizontal curve depends on the permissible design speed for the road. The values of minimum radii for various categories of roads in different areas, recommended by IRC.

Vertical curves are the curves provided at the intersections of different grades in the vertical alignment of highway. This is introduced to smoothen out the vertical profile and thus to ease off the changes in gradient for the fast moving vehicles.

Basic difference between GPS, GIS and Remote Sensing

2020-01-08T10:20:00.000+05:30

Basic difference between GPS, GIS and Remote Sensing

GPS (Global Positioning System)

The system which is used to find out the position at any corner of the Earth is known as Global positioning system (GPS).

GIS (Geographic Information System)

The system which gives information with the help of GPS in the form of data is known as Geographic Information System (GIS). It is the customizable electronic map that are created by compiling many different source of information.

Remote Sensing

The process in which sensor (attached in satellite) move around the earth to collect the information is known as Remote Sensing.

In Remote Sensing , there are two types of remote sensor :-
1) active sensor
2) passive sensor

Active sensor

It works in the night. It doesn't need sunlight to record data.

Passive sensor

It works in the presence of sunlight.

Remote sensing

Architecture vs Civil Engineering

2019-10-10T12:10:00.001+05:30

Architecture vs Civil Engineering

Architecture

Architecture is the art and science for practice of designing and constructing of any buildings. Architecture engineering is a part of engineering which deals with the technological aspects and multi-disciplinary approach to planning, designing, construction and operation of buildings, such as analysis and integrated design of environmental factors.

Civil Engineering

On the other hand civil engineering is also a part of engineering which deals with the design, construction, and maintenance of the physical and naturally built environment, including public works such as roads, bridges, canals, dams, airports, sewage systems, pipelines, structural components of buildings, and railways.

Architect and civil engineer both are playing an important role in the construction of the buildings. Architect and civil engineer is needed for different purposes.

An architect can not fulfill a civil engineer purpose nor a civil engineer can do that for an architect. So, we can say both are like left and right hand.

Functions of an Architect

An Architect enhance the exterior & interior beauty of a structure.

Architects provide proper arrangements for present and future needs with proper land utilization.

To design & arrange the rooms & facilities according to the desire.

To provide sufficient lighting, air circulation etc.

Architects

Functions of a Civil Engineer

Provide a safety measure to a building as well as workers.

Test the materials which is required in the construction of buildings.

Selection of a contractor to complete the works.

Supervision of construction of work.

Civil Engineers

Components of a modern buildings

2019-10-06T10:02:00.000+05:30

Components of a modern buildings

Foundation

Foundation is necessary to evenly distribute the entire building load on the soil in such a manner that no damaging settlement takes place. Hence, the foundation need to be constructed on good soil ground.

Plinth

Plinth is normally constructed just above the ground level and immediately after the foundation. It raises the floor above the ground level and herewith prevent surface water from entering the building.

DPC

DPC is a layer of waterproofing material such as asphalt or waterproofing cement. Walls are constructed above the damp proof course. DPC prevent surface water from rising into the walls. Dampness reduce the strength of the walls. DPC is not required where a plinth beam is constructed because plinth beam already performs like a DPC.

Plinth Beam

It is constructed depending upon the type of the structure of the building and nature of the soil it provides additional stability in the regard to settlement of the building and earthquake damages.

Floor

Flooring is laid over the feeling of the plinth and on subsequent floors. flooring is done to prevent dampness from rising to the top.

Walls

If the walls are very long columns can be provided to carry the roof it also provide privacy security and protection against natural element such as window rain and sunshine. Opening are to be provided in wall for access and ventilation.

Openings

Openings are normally provided in the walls as the doors, windows and ventilation doors provided access Windows and ventilation provide light and ventilation lentils are constructed just above the openings it is normally used on slab for concrete slab is the part of the ball that is just close the window lintel are constructed to hold of the walls above the openings in earthquake stone areas of continuous lintel beam is provided all over the walls.

Stairs

Apartment or room of a building in which there is located is called staircase the space for opening occupied by this year is called I stay away there are different kind of stairs are used in building like are there would and Square metal is player brick stair etc

Roof

It have different shapes but it is always as a flat or sloping it is made of assistant slab tiles etc

Surface / Finishes

It gives durability and pleasing appearance to the inside

Cement and its various kinds

2019-10-05T08:58:00.001+05:30

Cement and its various kinds

Cement is the binding material produced by burning together in definite proportion, a mixture of Calcareous (containing Silica) Argillacious (containing Aluminium) material at the temperature of about 1500°C by doing so a fused product is obtained called Clinker. The Clinker is cooled and then ground (grinding) to the required fineness and we get a substance called Cement.

Commonly used cement for normal construction work is known as Ordinary Portland Cement.

The approximate composition of raw materials used for manufacturing ordinary Portland cement are :-

Lime (62 to 67%)

Silica (17% to 25%)

Alumina (3% to 8%)

Ironoxide (1% to 6%)

Magnesia (1% to 4%)

Sulphur (1% to 2%)

Alkalis (0.5% to 1%)

Following are the important compound formed during the setting action of cement :-

1) Tricalcium aluminate

2) Tetracalcium aluminoferrite

3) Tricalcium silicate

4) Dicalcium silicate

Types of cement

Pozzolana cement

Pozzolana cement is produced either by grinding together cement clinker and Pozzolana or by intimately and uniformly blending Portland cement and fine Pozzolana.

Pozzolana cement produce less heat of hydration and offers greater resistance to attack of aggressive water or sulphate.

This cement is particularly useful in marine works and also in mass concrete structure.

Ultimate strength of the cement is more than that of ordinary cement but initial and final setting time are the same.

Quick Setting cement

It sets faster than ordinary Portland cement. Its initial setting time is 5 minutes and the final setting time is 30 minutes. It is used for making concrete that is required to set early as for laying under water or in running water.

Rapid Hardening cement

This cement gains strength faster than ordinary cement. Its initial and final setting time are the same as those of ordinary cement. It contains more of tricalcium silicate and is more finally ground. It gives out more heat while setting and is as such unsuitable for mass concrete work.

High Alumina cement

It is manufactured by fusing together a mixture of Bauxite and Lime stone in correct proportions and at high temperatures. It develop strength rapidly. It is black in colour and resist the attack of chemicals especially of sulphates and of sea water. Its ultimate strength is much higher than that of Ordinary cement. Its initial setting time is more than 2 hours and the final setting take place immediately thereafter.

It is used for such structure as are to be subjected to load early, for example repair of roads and bridges etc .

Low Heat cement

Heat generated by cement while setting may cause the structure to crack in case of concrete. Heat generation is controlled by keeping the percentage of Tricalcium Aluminate and tricalcium silicate low. Its initial and final setting times are nearly the same as those for ordinary cement. It is not very suitable for use in ordinary structure as this will prolonged the shuttering and also prolonged curing will have to be done.

White cement

It is a cement with pure white colour and having same properties as those of ordinary cement. Greyish colour of ordinary cement is due to ironoxide. It is manufactured from white chalk and clay free from iron oxide. For burning this cement oil fuel should be used instead of coal. It is much more costly than ordinary cement.

Structural elements of a modern building

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Structural elements of a modern building

Foundation

Foundation is the lowest part of the structure which provides a base or superstructure in a proper way.

Basic function of foundation is to transmit the Dead Load, Superimposed Load and Wind Load from the building to the soil on which the building rest in such a way that : -
1) settlements are within permissible limit without considering cracks in superstructure.
2) soil does not well well not transmitted to the subsoil.

Column
Column is a structural element which transfer the load through compression member to the foundation. There are many types of column such as square, rectangle, circular, etc.

Beam

Beam is a structural element that primarily resists loads applied laterally to beam' s axis. And then load transfered to the column . There are many types of beams like cantiliver beam, simply supported beam and continuous beam.

Slab

Slab is a common structural element of modern buildings, consisting of a flat, horizontal surfaces made of cast concrete. Slab has two types One Way Slab and Two Way Slab.

Structural elements of a RCC building

Note - we will explain all the structural elements in our next article.

RCC Framed Structure and Load Bearing Structure - Some basic differences

2019-09-21T11:52:00.001+05:30

RCC Framed Structure and Load Bearing Structure

We are going to discuss the difference between RCC framed structure and Load bearing structure. Load Bearing Structure is popularly known as Wall Bearing Structure and RCC Structure is known as Column Beam Structure.

RCC Framed Structure

In RCC Framed Structure, loads are transferred from slab to beam and beam to column and the finally transferred to the foundation.

Walls are constructed after the frame is ready. The thickness of wall is less as compared to the load bearing structure because the load is transferred only through frame.
There is no limitation of height of walls we can increase as much as we want. It can be constructed on any type of soil and resistance is very good for an earthquake. We required skilled labour for the construction of RCC buildings.

Load Bearing Structure

In Load Bearing Structure, load are transferred through the walls and finally transferred to the foundation. The thickness of wall must be more as compared to RCC framed structure. There is a limitation of height of walls. We cannot build more than three story. Both skilled and unskilled labour can work. We required hard strata for foundation.

Difference between RCC and Load Bearing Structure

Bricks, composition and its function

2019-09-16T17:52:00.002+05:30

Bricks wall

Bricks, composition and its function

Brick may be defined as the block of rectangular shape and suitable size that are made from suitable type of clay by different process involving moulding, drying and burning.
According to Wikipedia, a brick is building material used to make walls, pavements and other elements in masonry construction.
The depression on the top of brick is known as frog. The size of the frog is approximately 10 cm in length, 4 cm in width and 1 - 2 cm depth.
The common brick is one of the oldest building material and it is extensively used at present as a leading material of the construction because of its durability, strength, reliability, low cost and easy availability.
The Great Wall of China (210 B.C.) was built with both burnt and un burnt (sun dried bricks).
In India the standard size of traditional brick is recommended by Bureau of Indian Standard (BIS) is 9" × 4.5" × 3". The nominal size of brick as recommended by BIS is 19 cm × 9 cm × 9 cm without mortar. The size of brick tile is 20 cm × 10 cm × 10 cm with mortar. The size of the brick tiles is 19 cm × 9 cm × 4 cm without frog. The average weight of brick is 3.2 kg to 3.5 kg.

Composition of good brick earth

A good brick earth should be such that when prepared with water it can be easily moulded, dried and burnt without cracking or warping. The composition of good brick earth are clay ( alumina ) 20 - 30 % by weight, sand ( silica ) 50 - 60 % by weight, iron oxide 4 - 6 % by weight, lime 4 - 6% by weight, magnesia 1 - 2 % by weight.

Function of the constituents of good brick earth

Sand or Silica in brick earth prevents shrinkage, cracking and warping of bricks. But too much of sand will makes the brick brittle.
Clay or Alumina makes brick earth plastic and is capable of being moulded to any shape. If Clay or Alumina is present in excess, raw bricks shrink and warp during drying and burning.
A small amount of Lime is desirable in good brick earth. Excess of Lime causes the brick to melt and hence its shape may be lost.
A small amount of Iron-oxide helps lime to fuse sand and impart red colour to bricks. Excess of Iron oxide makes the bricks dark blue or blackish. If it is present in less quantity brick will be yellowish in colour.
A small quantity of Magnesia in brick earth imparts yellow tint to bricks and decreases shrinkage. But excess of Magnesia leads to decay of bricks.

Building and its classification - On the basis of utility

2019-09-03T08:57:00.000+05:30

Building and its classification

Definition of a building

The building is derived from the word "build" which means to construct something by putting parts together. According to Wikipedia, a building is a structure with a roof and walls standing more or less permanently in one place, such as a house or a factory.

Importance of building

● Building gives us shelter for survival.

● It protects from harmful effect like wind, rain, hail, etc. But it can't be protect from heavy or major disaster like Flood, Earthquake.
● We feel comfortable in a building.
● If the weather is hot then you can relax at your home.
And the another things like if the weather is cool then you can stay in a building and it prevent from harmful effects.

Classification of building

There are many buildings around us. Now, we can classified according to their uses which is mentioned below : -

1) Residential buildings

These buildings include one or two private dwellings apartment houses (flats ), hotels, dormitories, etc.

2) Educational buildings

These buildings include any buildings used for school, college purposes involving assembly for instuction, education or recreation.

3) Institutional buildings

These buildings include those buildings which is used for medical treatment etc. such as hospitals , nursing homes, orphanages, jails, prisons, mental hospitals etc.

4) Assembly buildings

These buildings may include those buildings which is used for recreation, amusement, social, religious or such types of purposes such as theatres, assembly hall, exhibition halls, restaurants, museum, club rooms etc.

5) Business buildings

These building include any building which is used for business transaction keeping records of accounts, town halls, city hall, court houses etc.

6) Mercantile buildings

These buildings may include those buildings which are used for shops, market, stores, wholesale or retail.

7) Industrial buildings

It is used for manufacturing purposes. For example, gas plants, refineries, mills etc.

8) Storage buildings

It is used for the storage of goods, wares like warehouse, garages etc.

9) Hazardous buildings

It is used for storage, handling, manufacture or production of highly combustible explosive materials or products such as acids, chemical products etc.

The Newby-McMahon Building, commonly referred to as the world's littlest skyscraper, is located at 701 La Salle (on the corner of Seventh and La Salle streets) in downtown Wichita Falls, Texas, United States. With a total height of 40 ft (12 m) tall. Its exterior dimensions are 18 ft (5.5 m) deep and 10 ft (3.0 m) wide. Its interior dimensions are approximately 12 ft (3.7 m) by 9 ft (2.7 m), or approximately 108 sq ft (10.0 m²).

The Burj Khalifa known as the Burj Dubai is a skyscraper in Dubai, United Arab Emirates. With a total height of 2,722 ft (829.8 m) and upto a roof height (excluding antenna) of 2,717 ft (828 m ). The Burj Khalifa has been the tallest building in the world.

The imperial is a twin - tower residential skyscraper in Mumbai which is one of the tallest building in India. With a total height of 827 ft (252m). It was designed by Hafeez Contractor.

Civil engineering study materials | Highway engineering | Structural elements of buildings

Classification of rocks

Classification of rocks

1) Geological classification of rocks

a) Igneous Rocks

b) Sedimentary Rocks

c) Metamorphic Rocks

2) Chemical classification of rocks

a) Siliceous Rocks

b) Argillaceous Rocks

c) Calcareous Rocks

3) Physical classification of rocks

a) Stratified Rocks

b) Unstratified Rocks

c) Foliated Rocks

Classification of bricks as per BIS

Classification of bricks as per BIS

Characteristic of first class bricks

Uses

Characteristics of second class bricks

Uses

Characteristic of third class bricks

Uses

Characteristic of over burnt bricks

Uses

Remedies for DPC

Remedies for DPC

Remedies to damp wall may be temporary or permanent according to the existence. Treatment to remove dampness would be different for internal and external wall. Temporary remedies for internal wall

Temporary remedies for internal wall

Application of bituminous painting

Painting with waterproofing solution

Applying cement wash

Temporary remedies for external wall

Coating with linseed oil

Sylvester's process

Painting paraffin

Permanent remedies

Dampness due to leakage from the roof

Vegetation

Earth banking

Cavities, hole etc.

Detect the exact spot open the space and fill the cavity with concrete.

Defective window sill

Dampness in hollow wall

Dampness, causes and its effect

Dampness, causes and its effect

Causes of dampness

Effect of dampness

Concrete and its type

Concrete and its type

Qualities of good concrete

Plain Cement Concrete

Lean Concrete

Reinforced Cement Concrete

Classification of roads

Classification of roads

Rural Road

Urban Road

Expressway

National Highway

State Highway

Major District Road

Other District Road

These roads serve rural areas of production and provide them access to market centres, block headquarter and Major District Roads.

Village Road

Arterial Roads

Sub Arterial Road

Collector Street

Local Street

Object of plastering and its requirement

Object of plastering and its requirement

Plastering

Object of Plastering

Requirement of Good Plaster

Classifications of Bridge as per Engineers

Classifications of Bridge as per Engineers

CLASSIFICATION OF BRIDGE

Purpose

Material used for construction

Life

Remedies to damp wall may be temporary or permanent according to the existence. Treatment to remove dampness would be different for internal and external wall.

Temporary remedies for internal wall