civil engineering prof asim ejazsoil property changes from place to place. the load from the...

w w w . a s i m s h e i k h 1 2 3 . w o r d p r e s s . c o m A . C . E . T . 1

CHAPTER 1

INTRODUCTION TO CIVIL ENGINEERING

Civil Engineering is the oldest branch of engineering which is growing

right from the Stone Age civilization. It involves planning design,

construction and maintenance of structures such as bridges, roads,

canals, dams, tunnels and multistoried building.

Civil Engineering as a profession in which a knowledge of the

mathematical and physical sciences gained by study, experience and

practice is applied with judgment to develop ways to, utilize

economically the materials and forces of nature for the progressive

well-being of man.

1.1 SCOPE OF CIVIL ENGINEERING:-

Scope of Civil Engineering may be divided into the following fields.

1. Surveying

2. Building Materials

3. Construction Technology

4. Structural Engineering

5. Geotechnical Engineering

6. Hydraulics

7. Water Resources and Irrigation Engineering

8. Transportation Engineering

9. Environmental Engineering

10. Town Planning

1. Surveying:

Surveying is the science of map making.

To start development activity in an area the relative positions of

various objects in the horizontal and vertical directions are required.

This is approved by surveying the area. Earlier, the conventional

instruments like chain, tape, and leveling instruments were used.

In this electronic era, modern equipments like Distance Meters and

Total Stations are used to get more accurate results easily.

2. Building Materials: Shelter is the basic need of civilization.

To get good shelter continuous efforts are going on right from the

beginning of civilization.

Prof Asim

Ejaz


Stones, bricks, timber, lime, cement, sand, jellies and tiles are the

traditional building materials.

Use of steel, aluminum glass glazed, tiles, plaster of Paris, paints and

varnishes have improved the quality of buildings.

A Civil Engineer must know the properties of all the building

materials so that they can be used appropriately.

3. Construction Technology:

Construction is the major activity or Civil Engineering which is

continuously improving.

As land cost is going up there is demand for tall structures in urban

areas while in rural areas need is for low cost constructions.

One has to develop technology using locally available materials.

In India, contribution of Central Building Research Institute (CBRI) -

Roorkee & Gaziabad, Nirmithi Kendras in technical development is

noteworthy.

4. Structural Engineering:

Load acting on a structure is ultimately transferred to ground. In

doing so, various components of the structure are subjected to internal

stresses.

Assessing the internal stresses in the components of a structure is

known as structural analysis and finding the suitable size of the

structural component is known as design of structure.

A Civil Engineer has not only to give a safe structure but he has to give

economical sections.

Frequent earthquakes in the recent years have brought importance of

analysis of the structure for earthquake forces.

All these aspects fall under structural Engineering field.

5. Geotechnical Engineering:

Soil property changes from place to place. The load from the structure

is to be safely transferred to soil.

For this, safe bearing capacity of the soil is to be properly assessed.

This branch of study in Engineering is called as Geotechnical

Engineering.

Apart from finding safe bearing capacity for foundation of buildings,

Geotechnical Engineering involves various, studies required for the

design of pavements, tunnels, earthen darns, canals and earth

retaining structures.

Prof Asim

Ejaz


6. Hydraulics:

Water is an important need for all living beings study of mechanics

of water and its flow characteristics is another important field in

Civil Engineering and it is known as hydraulics.

7. Water Resources and Irrigation Engineering:

Water is to be supplied to agricultural field and for drinking purpose.

Hence, suitable water resources are to be identified and water is to be

stored.

Identifying, planning and building water retaining structure like tanks

and dams and carrying stored water to field is known as water

resources and Irrigation Engineering.

8. Transportation Engineering:

Providing good and economical road is an important duty of Civil

Engineer.

Railway is another important long-way transport facility.

There is need for airports and harbors.

For proper planning of these transportation facility, carrying out

traffic survey, design, construction, and maintenance of roads,

bridges, railway, harbors and airports is known as transportation

engineering

9. Environmental Engineering:

Proper distribution of water to rural areas, towns and cities and

disposal of waste water and solids waste are another field of civil

engineering.

Industrialization and vehicular traffic are creating air pollution

problems.

Environmental engineering while tackling all these problems provides

healthy environment to public.

10. Architecture and Town Planning:

Aesthetically good structures are required. Towns and cities are to be

planned properly.

This field of engineering has grown considerably and has become a

course separate from Civil Engineering.

Prof Asim

Ejaz


1.2 ROLE OF ENGINEERS IN THE INFRASTRUCTURE DEVELOPMENT:-

A civil engineer has to prepare, plan, estimate, get approval, create and

maintain all civil engineering infrastructure activities. Civil engineer has a

very important role in the development of the following infrastructures:

1. Measure and map the earth’s surface.

2. Plan and develop extensions of towns and cities.

3. Build the suitable structures for the rural and urban areas for various

utilities.

4. Build the tanks and dams to exploit water resources.

5. Build river navigation and flood control projects.

6. Build canals and distributaries to take water to agricultural fields.

7. Purify and supply water to needy areas like houses, schools, offices etc.

8. Provide and maintain communication systems like roads, railways,

harbors and airports.

9. Construct systems for control and efficient flow of traffic.

10. Provide, build and maintain drainage and waste water disposal system.

11. Monitor land, water and air pollution, and take measures to control

them.

12. Fast growing industrialization has put heavy responsibilities on civil

engineers to preserve and protect environment.

QUESTIONS:-

1. Define Civil Engineering.

2. What is the scope of Civil Engineering?

3. Explain role of Civil Engineer in the infrastructure development of

country.

Prof Asim

Ejaz


CHAPTER 2

GENERAL CONCEPTS RELATED TO BUILDING

2.1 SELECTION OF SITE:-

For good planning and designing of building, the site selection of the

building is the most important aspect. The following points should be kept

in mind while selecting a site for building.

1. Site plot must be of clear title along with clear ownership rights of the

land.

2. The building site should be located on a fully developed or fast

developing locality

3. For happy living the neighborhood should be of equal status in the

society.

4. The shape of the plot shall not be irregular. As far as possible

rectangular plot should be selected, because maximum area of plot can

be used for construction.

5. The site should have general facilities such as sewer line, water line,

power connection, street lights, and facilities for drainage and garbage

disposal.

6. The site should be well connected by road by-pass and service lanes.

7. The site should have facilities of community services such as school,

primary health centre, shopping centre, post office, transport etc.

8. The site should be on an elevated land so as to have easy surface

drainage of rain water. The ground water table level at the site should

not be too high neither too low.

9. The soil conditions of the plot should be such that economical

foundation is possible.

10. The site should have good view of landscape such hills, gardens,

rivers, lake, seashore etc. to promote healthy and peaceful living.

Prof Asim

Ejaz


2.2 BASIC FUNCTIONS OF BUILDING:-

1. It should be sufficiently strong to withstand the effects of the

atmosphere and environment.

2. It should be durable and stable to take up the anticipated loads coming

on it including the self- weight, live load, wind load and earthquake

load.

3. It should be well ventilated and free from dampness. It should also

resist penetration of moisture.

4. It should provide maximum living and working comfort.

5. It should be dimensionally stable.

6. Grouping of rooms should be so planned so as to ensure circulation

and optimum utilization of space.

7. The building should be safe against fire hazards.

8. The building should be safe against theft. The external wall should be

made so strong to resist any such attempt.

9. The building should be sound insulating, so as to reduce sound

passing through it.

2.3 TYPES OF BUILDING:-

1. Residential Building:-

Residential Building is a building in which sleeping, living

accommodation along with cooking facilities are included for one or

more family.

These include apartment houses, flats, bungalows, chawls, cottages

and rest houses.

These should be located in residential zone. They should be placed in

calm, quiet and beautiful surroundings.

These should be located away from the industrial zone, so as not to

cause noise.

Prof Asim

Ejaz


2. Public Building: -

Public buildings are buildings where groups of people gather for

amusement, recreation, social, religious, civil purposes, travelling and

similar other purposes.

These buildings include:

Recreation- drama and cinema theatres, exhibition halls, museums,

restaurants, eating or boarding houses, places of worship,

dance halls, clubs etc.

Social gatherings - assembly halls, city halls, town halls, auditoriums.

Travelling purpose - road railway, air, sea or other public transportation

stations.

The public building are planned to provide good measure of the

development of that society.

They should have easy approach and availability of general facilities.

3. Commercial Building:-

These building include any building or part of building where mainly

transaction of business or keeping of accounts and records take place.

They include offices, banks, professional establishments, etc.

4. Industrial Building:-

These buildings include a building where mainly products or material

are fabricated, assembled or processed such as assembly plants,

laboratories, power plants, refineries, gas plants and factories etc.

These buildings should be located on the outskirts and placed on the

leeward side of the town so that smog, dust and noise created inside

the building does not affect the town.

Prof Asim

Ejaz


2.4 PRINCIPLE OF PLANNING FOR RESIDENTIAL AND PUBLIC

BUILDINGThese principle ensure proper and economical utilization of space.

The principle are as follows:

Aspect

Prospect

Orientation

Privacy

Circulation

Grouping

Roominess

Furniture Requirement

Sanitation

Elegance

Economy

Access

1. Aspect:

Aspect is defined as the positioning of windows and doors in the

external walls to take maximum advantage of natural's gifts such as

sunlight and wind or breeze.

Thus various rooms have different requirements and hence the aspect

changes as per the rooms

Kitchen should have its windows in eastern walls. As morning sunlight

has germ killing UV rays, the kitchen can be more hygienic in this way.

Bedrooms should have the west or south west aspect as in winter, the

sun is towards south, so the bedrooms will remain warm and during

summer, the sun is towards north, so the bedrooms will remain cool.

Also west is the general direction from which a breeze blows during

evening and night.

Drawing room, study room etc. should have northern aspect as

maximum light can be received from this direction.

2. Prospect:

Prospect means taking advantage of desirable views available from

windows, doors and balconies, of features outside the building such as

garden, lake, sea, river, hill etc.

Prof Asim

Ejaz


Prospect also means blocking of undesirable views, such as garbage

dump, slum, gutters, railway tracks, etc. by providing blank walls

without windows towards the undesirable views.

3. Orientation:

Orientation means placement of rooms with reference to the north

direction.

The same plane can be placed on the plot in various ways to give

different orientations.

According to the civil engineering, the plan should be orientated with

respect to the north in such a way that the kitchen lies towards cast and

north cast, bedrooms are towards south to south west and maximum

hall windows should face north-northwest.

4. Privacy:

There are two considerations to the principal of privacy:

a) External Privacy

This mean privacy of the entire building from surrounding buildings.

Privacy from noise and pollution from the road. Also privacy from

congestion due to crowding of building.

External privacy can be maintained by good planning.

b) Internal Privacy

This means prevention of direct view inside any room from any other

room or from passage. Proper placements of doors ensure the internal

privacy.

Staggering of the doors, instead of all doors in a straight line, proper

placing of the shutters of the doors, using single shutters doors instead

of double shutters doors, use of screens, proper furniture arrangement,

etc. are some measure to ensure internal privacy.

Prof Asim

Ejaz


5. Circulation:

Circulation refers to movement from one room to the other inside the

building. The doors must be arranged in such a way that minimum

space is wasted in circulation. The wastage of space also depends on

which side the door is hinged.

Also, doors in the corner of a room are always preferable to doors in

the center of wall.

a) Horizontal Circulation:

This means the movement of the persons from rooms of same floor.

b) Vertical Circulation:

This means movement from one floor to the other floor. For vertical

circulation, stair case, ramps or lifts are provided.

6. Grouping:

This means planning rooms with same or similar functions together as

a group. This principal is more applicable in public building.

In residential buildings grouping of W.C., bath and kitchen along the

side of the house facilitate the water supply and drainage

arrangements. In grouping, kitchen and dining should be grouped

together.

7. Roominess:

A psychological feeling about bigness or smallness of space, e.g. of a

room, is called roominess. This is a very interesting principle; it is

common observation that a square room appears smaller than a

rectangular room of exactly the same area.

This is an illusion, and though it seems mysterious, there is a reason

for it. A rectangular room has greater perimeter than a square room of

the same area.

8. Furniture Requirement:

While planning a building, if the furniture requirements are taken into

account definitely leads to a better and more, aesthetically pleasing

plan. A plan prepared by a civil engineer, who has learned interior

decoration also is radically different than a plan by a mere Civil

Engineer.

Prof Asim

Ejaz


What this means is, while planning, conscious attention should be paid

to what type and what type of furniture a particular room is going to

contain after completion.

The furniture arrangement must not create hurdles in circulation, On

the other hand, positioning of doors should be such that furniture

rearrangement can be done easily achieving economy of space.

9. Sanitation:

Sanitation is concerned with lighting and ventilation. It also includes

proper planning for drainage arrangement. For ventilation and light,

each room must have minimum window space.

Generally each room must he planned in such a way that 10% to 15%

of floor area is provided for window openings.

Air-conditioning also comes under sanitation. If air conditioning is to

be provided, it must be taken into account right from planning stage

itself.

10. Elegance:

It refers to the elevation of the building. The front elevation of the

building must be aesthetically pleasing and elegant.

Ugly features such as drainage pipes, radiators of air-conditioners

should be avoided in the front view.

Proper elevation treatment with decorative plasters, claddings etc. will

make the building elegant and hence attractive at the first sight.

11. Economy:

The planning of building should be economical, avoiding all types of

wastage.

The wastage is not only of raw materials, but wastage of space will

greatly affect the economy of planning. Judicious use of space leads to

a proper planning and economy.

Inventory keeping is another aspect of economy. Especially for a large

project knowledge of material management is essential to achieve

economy.

Prof Asim

Ejaz


12. Access:

The principle of access stresses the need for ease in moving from one

room to other room. According to this principle, it must be possible to

go from a room to any other room, without having to cross a third

room. -

If the guest has to go through the bedroom, the kitchen and then wash

the hands at the wash-basin, it speaks of poor planning and lack of

proper access. Passages and corridors can be provided for easy access.

2.5 ORIENTATION OF BUILDING:

The setting of plan of the building on its site with reference to the directions

is knows as orientation and it plays a great role in increasing its utility from

the view point of climate considerations.

Following are some of the suggestions for good orientation of the buildings

1. Cross ventilation:

Sufficient number of windows and ventilators at suitable level from the

floors should be provided to cause movement of air for developing

comfortable conditions inside the building.

If this is not possible as in the case of the public buildings, resort should

be taken to artificial ventilation.

2. Damp-proof course:

It is desirable to provide damp- proof course at suitable level to keep

away walls from damp.

In a similar way, the overhanging of roofs on south and west will help

in protecting the walls from the rain.

3. Placing of walls:

The long wall of the building should be placed towards north and

south. The short wall on the other hand should be placed towards east

and west.

Such a placing of walls would result in exposing less area of wall to the

sun rays and it will assist in maintaining comfortable temperature

inside the building.

Prof Asim

Ejaz


4. Projections:

If projections in the form of balconies, verandahs etc. are provided on

east and west sides, the adjoining rooms remain comparatively cool.

5. Roof:

RCC flat roofs should be provided with water proofing treatment and

pitched roofs should contain valley gutters for draining rain water.

6. Wind direction:

The orientation of building should be such that advantage is available

for enjoying the natural breeze.

2.6 INTRODUCTION TO BUILDING BYE-LAWS:

These are the restriction laid down by the municipal, town planning or

revenue authorities on construction and planning of different types of

building.

Thus building bye-laws differ from place to place. For example

building bye-laws for Mumbai will not be same as that of some district

or taluka place having municipality or s village having gram

panchayat.

The above mentioned authorities sanction the building plans only after

scrutinizing them regarding the bye-laws.

1. Building Line:

Building line refers to the line upto which a building can lawfully

extend. It is also called as set back or front building line.

A minimum distance of this building line from the centre line of the

accompanying road is laid down as the limit beyond which no

construction is allowed towards the road.

In case of public buildings such as cinema halls and factories, the

buildings attract more number of people and vehicles as such space is

required.

Hence, the buildings should be set back a further distance away from

the building line. The line, which accounts for this extra margin is

called as control line.

Prof Asim

Ejaz


2. Height of Building:

General criteria to decide the height of the building as per N.B.C. is 1.5

times the width of the street to which it is on its front side.

The height of building can be decided on the basis of,

i) Width of front street ii) Vicinity of aerodromes.

The height of budding which will be decided on street width is given

in following table.

Sr. No. Width of Street Height of the Building

1 Upto 8 m Not more than 1.5 times width

2 8 m-12 m Not more than 12 m

3 Above 12 m Not more than width of street & Not more

than 24 m

3. Open space Requirement:

The sufficient open spaces, inside and around the building should be

left to meet with the requirements regarding lighting, ventilation,

future expansion, and approach.

Open space for front, rear and side yards depend upon height of

building and can be calculated by the formula.

W = width or open space around the building in m = 3 + (h/10)/3

h = height of building in m < 25 m

4. Set back distance:

It is the distance measured from centerline of road upto which plinth

of building may extend.

It is provided to facilitate future road widening, parking of vehicles;

free circulation of air etc.

Sr.

No.

Height of

Building

Open Space Requirement

1 Less than 10 m

Front open space width:

i) For building with front street – minimum 3 m

ii) For building with street on two or more sides

- average 3 m and in no case less than 1.8 m

2 10 m to 25 m Requirement as per sr. no. 1 is increased at the

rate of 1 m for every 3 m

3 25 m to 30 m Minimum 10 m

Prof Asim

Ejaz


Set back distance is about 1.5 to 1.67 times more for theatres,

commercial complexes, and factories than residential building.

Types of Road

Minimum Set Back Ratio of

column 3 to

column 2 Residential

Building

Industrial

Building

Village road 9 m 15 m 1.67

Major District

Road 15 m 24 m 1.60

National or State

Highway 30 m 45 m 1.50

Area Statement:

Area statement is provided for each building drawing as it gives details

of the total plot area and how much of the total area is utilized for

building.

The minimum details required in the area statement are:

1. Total plot area. 2. Built up area. 3. Floor space index or Floor area

ratio.

Other additional details can be shown in the area statement such as

carpet area, Plinth Area, Converted Balcony or Terrace Area etc.

5. Floor Space Index or Floor Area Ratio (F.S.I. or F.A.R.):

It is defined as the ratio of the total built-up area of all the floors IO the

total area of plot.

F. S. I =Total Built up area of all the floors or storeys

Plot area

For Example: - Built-up area of 1000 m2 is constructed on each floor of (G +

2) building. Plot area is 3000 m2. Find F.S.I.

F. S. I = Built up area of 1st floor+ +2nd floor

Plot area =

1000+ 1000+1000

3000 = 1

It limits the floor area of a building in relation to the plot area.

The value of F.S.I. is determined by local authority and it may be

different for different areas and for different buildings of the town.

Prof Asim

Ejaz


The F.S.I. controls the development activity on the plot of land mid it

on he used as a measure to check density of population.

The F.S.I. changes as per the locality. In gaothan area F.S.I. is more than

non-gaothan, suburb or outskirts are of a town.

6. Carpet Area:

It is defined as actual area of usable room at any floor level. (Literally

means the area where carpet can be laid).

It does not include sanitary accommodations, verandahs, corridors and

passages, stores in domestic building, staircases, shafts for lifts,

garages, air condition ducts and air-conditioning plant room.

7. Built up Area:

• It is the area covered by all floors of a building,

• This includes everything covered under roof. Area occupied by

balcony, staircase is excluded from the built up area.

Following are the limitations of build-up area recommendation.

8. Ventilation:

• The system of supplying or removing air by natural or mechanical

means to any enclosed space to create and maintain comfortable

condition is known as ventilation.

• For healthy living more sunlight less overcrowding and fresh air are

necessary for a house. Ventilation is necessary for the supply of oxygen

for breathing and to prevent undue rise in carbon dioxide content in

air.

Sr. No. Area Recommendations

1 Market Area Construction area should not exceed 75

% area of site

2 Industrial Area Construction area should not exceed 60

% area of site

3 Residential Area Construction area should not exceed 60

% area of site

Prof Asim

Ejaz


• The residential buildings are planned such that natural system of

ventilation shall be achieved. It will be achieved by placing window as

per the direction of wind.

• There are some ventilation systems such as.

a) Natural Ventilation - Natural inlet & Natural outlet.

b) Exhaust system - Natural inlet & Mechanical outlet.

c) Balance System - Mechanical inlet & Mechanical outlet.

QUESTIONS

1) Which factors should be kept in mind while selection of site for building

constructions?

2) Explain the different functions of building.

3) Write the different types of buildings explain one of them.

4) Explain Principles of planning.

5) Explain orientation of building.

6) Explain building bye- laws with respect to carpet area, built-up area,

Height of building, built up area and Ventilation.

7) Write short notes on

8) Floor Area Ratio.

9) ii) Set-backs

Prof Asim

Ejaz


CHAPTER 3 COMPONENTS OF BUILDINGS

INTRODUCTION:

A building has the following component:

1. Foundation or Substructure

2. Masonry unit: walls and columns

3. Floor structure

4. Roof Structure

5. Doors, windows and other opening

6. Vertical Transportation structure

7. Building finishes

Prof Asim

Ejaz


1. Foundation or Substructure:

The portion of building which is below plinth level is own as sub-

structure of foundation.

The function of a foundation is to distribute the loads of the structure

over a greater area so as to bring intensity of loading within the safe

bearing capacity of the soil.

It is built on a naturally or artificially created stable ground.

2. Masonry Unit:

Masonry may be defined as the construction of building units bonded

together with mortar that includes walls and columns.

3. Floor structure:

Floors are the horizontal elements which divide the building into

different levels for the purpose of creating more accommodation for

the occupants.

Equipments of a building within a restricted space.

4. Roof Structure:

Roof is the upper most part of a building. It is a covering provided on

the top of the building with a view to keep away rain, snow sun and

wind to protect the building from their adverse effect.

5. Door, Window and Other Opening:

A door is a movable barrier provided in the opening of a wall to

provide access to various spaces of a building.

Window is an opening made in the walls for air circulation, ventilation,

day light etc., similarly, an access may be provided to span the opening

in the place of a lintel.

6. Vertical Transportation Structure

These consist of stair, ramps, lifts, etc., to access between various floors.

7. Building Finishes:

Building Finishes are used to give protective covering to various

building components and at the same time they provide decorative

effect.

Prof Asim

Ejaz


It consist of plastering, pointing, painting, varnishing & polishing,

white washing, distempering, colouring etc.

3.2 TYPES OF LOADS ON BUILDING:

The basic requirement of any structural member of a building is that it should

be strong enough to carry or support all the possible types of loads which act

on it. The different types of load are as follows

1. Dead Load.

2. Live Load or imposed load.

3. Impact Load.

4. Wind load.

5. Snow Load.

6. Earthquake load.

1. Dead Load:

Dead loads are permanent or stationary loads which are transferred to

structure throughout the life span.

The dead load in a building comprises the weight of roofs, floors,

beams, columns, walls, partition walls etc.

2. Live Load:

The loads which keep on changing from time to time are called as live

loads.

Common examples of such moving loads in a building are the weight

of the persons, weights of movable partition, weight of furniture's,

home appliances, equipments etc. These loads are to be suitably

assumed by the designer. It is one of the major loads in the design.

3. Impact Load:

Impact load is caused by vibration or acceleration.

Thus impact load is equal to imposed load incremented by some

percentage. For example: vibration of moving vehicle or machines.

4. Wind Load:

When wind is obstructed by the structure, it exerts a pressure on the

structure known as wind pressure.

Prof Asim

Ejaz


Wind pressure acts horizontally on the exposed vertical faces of the

structure.

Wind load is effective in case of tall building.

5. Earthquake Load:

Earth causes horizontal and vertical ground shaking. The horizontal or

vertical shaking is usually most critical on buildings.

Every building and its portions should be designed and constructed to

resist the effect of earth ground motions.

6. Snow Load:

Snow Loads act on roofs. Roots should be designed for actual loads due

to snow (or for the imposed loads), whichever is more severe.

For the building to be located in the regions wherever snow is likely to

fall, this load is to be considered. Mountainous regions in northern

parts of India are subjected to snow fall.

3.3 TYPES OF SOIL:

Following are the various types of soils which art generally used in building

practice,

1. Black Cotton Soil:

It is very low bearing capacity and has high expansive and shrinkage

properties.

Its colour varies from dark grey to black.

It is very common soil occurred in many region of India.

It is good for cultivation and not suitable for any building structure to

build on it.

The name is derived from the fact that cotton grows well in the black

soil.

2. Clay:

It consists of microscopic and sub-microscopic particles derived from

chemical decomposition of rocks.

It is a fine-grained and cohesive (closely united) soil.

It exhibits considerable strength when dry.

Prof Asim

Ejaz


3. Dune sands:

These are wind transported soils.

These are composed of relatively uniform particles of fine to medium

sand.

4. Gravel:

Gravel is a type of coarse grained soil.

The particle size ranges from 4. 75 mm to 80 mm it is a cohesion less

material.

5. Loam:

Mixture of sand, silt and clay size particles approximately in equal

proportions; sometimes contains organic matter.

6. Loess:

It is wind-blown yellowish brown silt. It is generally of uniform

gradation.

It consists of quartz and feldspar particles.

When wet, it becomes soft and compressible.

Near vertical cuts can be made in the dry condition.

7. Sand:

It is a coarse grained soil; having particle size between 0.075 mm to 4.75

mm.

The particles are visible to naked eyes. The soil is cohesion less and

pervious.

8. Silt:

It is a fine grained soil; with particle size between 0.002 mm to 0.075

mm.

The particles are not visible to eyes.

9. Moorum:

The word morrum is derived from a Tamil word, meaning powdered

rock.

It consists of small pieces of disintegrated rock or shale, with or without

boulders.

Prof Asim

Ejaz


10. Laterites:

These soils are also called as lateritic soils. Laterites are residual soils

formed in tropical regions.

Laterites are very soft when freshly cut but become hard after long

exposure owing to the formation of hydrated iron oxides.

11. Bentonite:

Decomposed volcanic ash containing a high percentage of clay

mineral-montmorillonite.

It exhibits high degree of shrinkage and swelling.

12. Boulder clay:

Glacial clay containing all sizes of rock fragments from boulders down

to finely pulverized clay materials. It is also known as ‘Glacial till’.

13. Caliches:

Soil conglomerate of gravel, sand and clay cemented by calcium

carbonate.

14. Hard pan:

Densely cemented soil which remains hard when wet. Boulder clays or

glacial tills may also be called hard-pan. It is very difficult to penetrate

or excavate.

15. Marl:

It is a mixture of calcareous sands or clays or loam; clay content not

more than 75% and lime content not less than 15%.

16. Top-soil:

It is a surface material which supports plant life.

17. Varved clay:

Clay and silt of glacial origin, essentially a lacustrine deposit; varve is

a term of Swedish origin meaning thin layer.

Thicker silt varves of summer alternate with thinner clay varves of

winter.

Prof Asim

Ejaz


3.4 TYPES OF ROCKS:

ROCKS:

Rock may be defined as aggregate of two or more minerals. A rock represents

a definite portion of the earth's surface. They occur almost everywhere in

mountainous and hilly areas. Types of rocks depend upon its classification.

Hence natural rocks are classified as,

I. Geological classification: - Igneous rocks, Sedimentary rocks, metamorphic

rocks.

II. Chemical classification: - Siliceous rocks, Argillaceous rocks, Calcareous

rocks.

III. Physical classification: - Stratified rocks, Unstratified rocks, Foliated

rocks.

1. Igneous rocks:

At the time of volcanic eruptions, molten mass called as magma forcibly

comes up on the surface of the earth at high temperature. After cooling down

it becomes solid mass which is called as igneous rock. Examples are Granite,

Dolerite and Basalt.

2. Sedimentary rocks:

Because of weathering action such as rain water, wind, snow, sunrays etc.

the principal rocks are broken down and get deposited at the bottom of river

over the years. This kind of formation of rocks is called sedimentary rocks.

Examples are Sandstone, Limestone, and Gypsum.

3. Metamorphic rocks:

The rocks which are formed from igneous rocks and sedimentary rocks

under the influence of pressure, temperature, and chemical environment are

called as metamorphic rocks. Examples are Marble, Slate, Quartzite and

Gneiss.

4. Siliceous rocks:

The main constituent of this rock is silica. These type of rocks are hard,

durable and resistant to weathering action. Examples are Granite, Sandstone,

Trap, Quartzite, and Gneiss.

Prof Asim

Ejaz


5. Argillaceous rocks:

The main constituent of this rock is clay. These rocks are composed of

alumina and small quantities of siliceous and calcareous material. Examples

are Slate, Laterite and Schist.

6. Calcareous rocks:

The main constituent of this rock is calcium carbonate. The durability of these

rocks depends on texture, constituents of the atmosphere and atmospheric

conditions. Examples are Marble, Limestone and Conglomerate.

7. Stratified rocks:

The rocks having many strata and can be split up along there cleavage planes

into thin layers are called as stratified rocks. Sedimentary rocks belong to this

type of rocks. Examples are Slate and Compact limestone.

8. Unstratified rocks:

The rocks not having any strata but containing granular crystalline grains are

called as unstratified rocks. Igneous rocks belong to this type of rocks.

Examples are Granite, Gneiss and Sandstone.

9. Foliated rocks:

The rocks having foliated or banded structure and can be split up in one

definite direction is called as foliated rocks. Examples are Marble and

Quartzite.

3.5 CONCEPT OF BEARING CAPACITY:

3.5.1 Bearing Capacity of Soil:

The bearing capacity of soil is the maximum load per unit area which the soil

or material in foundation, may be rock or soil, will support without

displacement. It depends upon the cohesiveness, frictional properties and

unit weight of subsoil. It can be determined by directly by a test known as

plate load test.

𝑆𝑎𝑓𝑒 𝐵𝑒𝑎𝑟𝑖𝑛𝑔 𝐶𝑎𝑝𝑎𝑐𝑖𝑡𝑦(𝑆. 𝐵. 𝐶. ) =𝑈𝑙𝑡𝑖𝑚𝑎𝑡𝑒 𝑏𝑒𝑎𝑟𝑖𝑛𝑔 𝑐𝑎𝑝𝑎𝑐𝑖𝑡𝑦

Factor of safety

3.5.2 Safe Bearing Capacity:

The maximum intensity of loading that the soil will safely carry without risk

of shear failure is called safe bearing capacity. And this is obtained by

Prof Asim

Ejaz


dividing the ultimate bearing capacity by a certain factor of safety and is used

in the design of foundation.

The factor of safety is 2 for ordinary building & 2.5 to 3.0 for

heavier/important building.

3.6 FOUNDATION:

Foundation

The foundations are classified in two types: l. Shallow Foundation 2. Deep

Foundation

I. Shallow Foundation: A foundation is shallow, if its depth is equal to or

less than its width, suitable for hard strata.

Type of Shallow Foundation:

1. Spread footing

2. Strap Footing

3. Combined Footing

4. Raft Footing.

1. Spread footing:

Further Spread Footing classified into-

a) Single Footing

b) Stepped Footing

c) Wall Footing

d) Grillage Footing

a) Single Footing: This type of foundation is suitable when there is a good

strata at low depth and depth of foundation is low and load is less.

Fig. Single Footing

Prof Asim

Ejaz


b) Stepped Footing & Sloped Footing: This type of foundation is suitable

when there is a good stratum at low depth but foundation is some more

deep as compared to single footing and load is more.

Fig. Stepped Footing Fig. Sloped Footing

c) Wall Footing: Wall footing is suitable for load bearing structure where

depth is low and load is also less.

Fig. Wall Footing

d) Grillage Footing: When heavy structural loads from column piers are

required to be transferred to a soil of less bearing capacity. This

foundation is found lighter and more economical. It also avoids deep

foundation.

Concrete Pad

Fig: Grillage Footing

Prof Asim

Ejaz


2. Strap Footing: If the independent footings of two columns are connected

by a beam it is called a strap footing. It is used when distance between

column is more and combine footing is not possible. It is also useful when

any old existing structure is so near to the footing and the existing

structure does not permit the independent footing of column.

Fig : Strap Footing

3. Combined Footings: A spread footing which support two or more column

is termed as combined footing.

Combined footings may be of the following type:

a) Rectangular combined footings: The combined footing for columns will be

rectangular in shape if they carry equal loads.

b) Trapezoidal combined footing: If the columns carry unequal loads, the

footing is trapezoidal shape.

(Elevation) (Elevation)

(Plan) (Plan)

Fig: Rectangular combined footings Fig: Trapezoidal combined footing

Prof Asim

Ejaz


4. Raft Footing: A raft or mat is a combined footing that covers the entire

area below the structure and supports all the columns when the safe

bearing capacity of soil is low and the building loads are heavy.

Fig: Mat / Raft foundation

II. Deep Foundation: Deep foundation the depth is equal to or greater than

its width. Suitable for low bearing capacity of soil.

Types of deep foundation:

1. Pile Foundation

2. Pier Foundation

3. Well or Caisson Foundation

1. Pile Foundation: When heavy concentrated loads have to be carried out

through soil strata of low bearing capacity to deeper soil or rock having

higher bearing capacity.

a) Bearing Piles: Piles are the poles made of timber, plain concrete, R.C.C. or

steel. These piles are hammered clown to rest on hard surface. On top of

a number of piles a concrete cap is cast and over that construction activity

of building starts. Thus bearing piles transfer the load to hard surface

directly.

Prof Asim

Ejaz


b) Friction Piles: When hard surface is not met at reasonable depth, the

frictional resistance between the adjoining soil and pile is checked and the

pile length is kept sufficient enough to transfer the load by friction.

2. Pier Foundation: Pier foundations are somewhat similar to pile

foundations but are typically larger in area than piles. A pier is a heavy

structural member. Usually, pier foundations are used for bridges.

Fig: Pier foundation

3. Caisson or Well foundation: A 'Caisson' is a box shaped type of

foundation, built above ground level and sunk to the required depth as a

single unit. They are used to refer to a water-tight chamber employed for

laying foundations under water as in lakes, rivers, seas, and oceans. A

Prof Asim

Ejaz


special type of open Caissons used in India are known as "well

foundation". Well foundations have been used in India for centuries for

providing deep foundations below water for monuments, bridges, and

aqueducts. For example, the famous Taj Mahal at Agra stands on well

foundations.

Fig: Caisson foundation

3.7 SUPERSTRUCTURE:

It is that part of structure which is above ground level and which serves the

purpose of its intended use. A part of the superstructure located between the

ground level and the floor level is known as plinth.

Plinth: Plinth is defined as the portion of the structure between the surface

of the surrounding ground and surface of the floor, immediately above the

ground. The level of the floor is usually known as plinth level and built-up

covered area measured at this floor level is known as plinth area.

Prof Asim

Ejaz


3.7.1 Types of Construction:

1. Load Bearing Structure:

In load bearing structures the entire load of the superstructure is

transmitted through the walls to the soil below the ground.

These walls are supported on continuous foundations that rest on hard

strata. Thickness of such walls is large.

If the number of storeys is increased the thickness of the wall increases.

This type of construction reduces the carpet area.

This type of construction cannot be used for multistoried building.

2. Framed Structure:

Framed structure consists of a series of frame made up of beams and

columns.

Walls are constructed within the frames which are known as partition

walls.

Thus the loads of floor roofs and partition walls are supported by beams

which in tum, transmit the load to the columns.

Columns transmit the load to the foundation, which rests on a hard soil

below the ground.

Framed structures are suitable for medium and multistoried building.

3.7.2 Comparison between Load Bearing Structures and Framed

Structures.

Sr.

No.

Items for

comparison

Load Bearing

Structure Framed Structure

1 Soil condition

It can be constructed

on hard strata

available at shallow

depth

It can be constructed on

any type of soil. Ex – Black

cotton soil, soft soil

2 Material

Load bearing walls

are constructed of

bricks and stones.

In framed structure,

column, beams and slabs

are constructed of

Reinforced Cement

Concrete (R.C.C.)

Prof Asim

Ejaz


3 Floor space

Less floor area is

available for use due

to thick walls.

More floor area is

available for use due to

thinner walls

4 Openings

Too many openings

for doors, windows

etc. are not

permissible

There is no such

restriction in framed

structure.

5

Height /

Number of

storeys

Height is limited

and it is suitable for

2 to 3 storeys

No restriction on height.

Suitable for multistoried

building.

6 Dead Load More due thick wall. Less due to thin walls

7 Time of

construction

For same number of

storeys, time require

is more.

For same number of

storeys, time require is

less because different

construction activities can

be carried out at the same

time.

8 Flexibility in

planning

Less flexible due to

load bearing walls.

More flexible due to wall

serving as a partition only.

9 Earthquake

resistant

Susceptible to

vibration due to

earthquake.

Can be designed to resist

more earthquake

vibrations.

10 Economy Cheaper upto 2

storeys.

Economical for

multistoried buildings.

QUESTIONS

1. What are different types of loads on building?

2. Define Bearing Capacity of Soil.

3. What do you mean by Superstructure and Substructure?

4. What are components of a building? Explain any one.

5. Explain the different types of foundation with their suitability.

6. List and define different types of soil.

7. Explain different types of rocks.

8. Differentiate between Load Bearing and Framed Structure.

Prof Asim

Ejaz


CHAPTER 4

BUILDING MATERIALS:

4.1 INTRODUCTION TO BASIC CONSTRUCTION MATERIALS:

Basic construction materials are cement, bricks, stones, aggregates,

reinforcing steel, structural glazing, structural steel.

4.1.1 CEMENT:

The product obtained by burning and crushing to powder form which is

a homogeneous and well-proportioned mixture of lime stone (calcareous

material) and day (argillaceous material) is known as cement. Commonly

used grayish coloured cement is known as ordinary Portland cement.

1. Natural cement: It is manufactured by burning and crushing natural

cement stones, which contains calcareous material and argillaceous

material.

2. Artificial cement: It is manufactured by burning appropriately

proportioned mixture of argillaceous and calcareous materials at a very

high temperature and then grinding the resulting burnt mixture to a fine

powder.

GRADES OF CEMENT:

The Bureau of Indian Standards (BIS) has graded the ordinary Portland

cement into three grades as.

33 Grade Ordinary Portland Cement conforming to IS 269



The compressive strength of these cements at 28 days is at least or not less

than 33 MPa (N/mm2), 43 MPa, and 53 MPa, respectively. Separate

specifications have been brought out for each grade of cement to deal with

their physical and chemical properties.

Prof Asim

Ejaz


TYPES OF CEMENT:

The various types of cement available can· be classified as follows:

1. Ordinary Portland cement

2. Rapid Hardening Portland

cement

3. Expansive cement

4. Sulphate resisting cement

5. Blast furnace slag cement

6. White and coloured cement

7. Water repelling cement

8. Water proof cement

9. Quick setting cement

10. High alumina- cement

11. Low heat Portland cement.

12. Expansive cement

13. Oil-well cement

1. Ordinary Portland cement: This type of cement is suited for general

construction work for making, cement mortar and concrete. It is not

affected by sulphates in soil or in ground water.

2. Rapid hardening Portland cement: It attains greater strength at early age.

This cement is used in construction work when early strength is necessary

for early removal of formwork for reuse, to open the road to traffic with

minimum delay; winter concreting, urgent repair works etc.

3. Low heat Portland cement: The heat of hydration generated in mass

concrete structures is dangerous because it may cause cracks due to the

development of internal stresses during setting. Hence, this cement which

generates low heat of hydration is very suitable for mass concrete

structures such as retaining walls, dams, and bridges etc.

4. Sulphate resisting cement: It resists the action of acids, alkalies, fumes

gases and sea water. Hence, it is used for the construction of tanks, pipe

lines, sewers etc. at chemical plants. It is also used for the construction of

docks, harbors to protect them from the action of sea water.

5. Blast furnace slag cement: It is similar to ordinary Portland cement and

can be used in all the places where ordinary Portland cement is used. In

addition, in view of its low heat evolution it can also be used in mass

concrete structures, such as dams, retaining walls, foundations, bridge

and abutments. This cement is more resistant to sulphate attack and is

Prof Asim

Ejaz


specified for marine works or pipe carrying water containing chemicals

or sewage.

6. White and coloured cement: It is a ordinary Portland cement white in

colour. White cement is costly and is used only for interior decoration and

architectural finish works such as external rendering of building, facing

slabs, terrazzo tiles and floorings bathrooms water closets, garden paths,

swimming pools ornamental concrete products etc.

7. Water repelling cement: This type of cement is chiefly used in water tight

concrete and water tight rendering to check moisture penetration in

basement etc. and for coloured rendering and stucco. Considerable care is

needed to avoid reduction in strength if such cement is used in concrete.

8. Water proof cement: It is used for the construction of water retaining

structures like tanks , reservoirs, retaining walls swimming pools, dams

bridges, piers etc. it is more resistant to corrosive action of acids and

alkalies or other harmful salts usually present in industrial waters.

9. Portland pozzolana cement: This cement produces low heat of hydration

and has a greater resistance to attack of chemical agencies. Hence,

concrete made with cement is considered particularly suitable for

construction in sea water, hydraulic works and for mass concrete works.

10. Quick setting cement: When concrete is lo be laid under still water or i11

running water, this cement is used advantageously. The setting action of

such a cement starts within five minutes and it becomes stone hard in less

than an hour.

11. High alumina cement: This cement has excellent resistance to action of

sulphates, acid water, sea water, fire. The rapid hardening quality of this

cement permits the early removal of formwork. This reduces the in places

where repeated use of formwork is possible.

12. Expansive cement: The concrete made with expansive cement will have

no tendency of shrinkage or expansion (shrinkage being compensated by

expansion). This cement can be used for the construction of roof slabs,

canal lining, tunnel lining, concrete parchment etc.

Prof Asim

Ejaz


13. Oil well cement: A special type of cement that is Oil well cement is

required for sealing oil wells. Sealing is necessary to prevent the side of

the freshly drilled well from collapsing and to keep ground water out of

well shaft.

FIELD TEST OF CEMENT:

It is not possible to check the quality of cement in a laboratory. In order

to check the quality of cement on field, following methods are adopted:

1. Colour test:

Colour of cement should be uniform.

It should be greenish grey.

2. Presence of lumps:

Cement should be free from any hard lumps.

Lumps are formed by absorption of moisture.

Such cement must be rejected.

3. Cement adulteration test

Cement should feel smooth when touched or rubbed in between

fingers.

If it felt rough, it indicate adulteration with sand.

4. Temperature test

If hand is inserted in bag of cement, it should feel cool and not warm.

5. Float test:

If small quantity of cement is thrown in a bucket of water, the particles

should float for float for some time before it sinks.

6. Date of packing:

Strength of cement reduces with time, so it is important to check

manufacturing date of cement.

4.1.2 BRICKS

Bricks are obtained by moulding a mixture of clay and sand in the

rectangular blocks of uniform size and then by drying and burning these

blocks at high temperature. Bricks are very popular as they are easily

available, economical, strong durable and reliable. It is found that the

Prof Asim

Ejaz


weight of l m3 of brick is about 1800 kg. Hence the average weight of the

brick will be about 3 to 3 .5 kg.

CLASSIFICATION OF BRICKS:

Classification of Bricks (As Per Size):

Bricks can be classified into two types,

1. Conventional or traditional bricks:

The dimensions of conventional bricks vary from 21 to 25 cm in length, 10

to 13 cm in width and 7.5 to 10 cm in height in different parts of the

country.

The commonly adopted size or conventional bricks is 23 cm x l1.4 cm x 7.5

cm.

2. Standard bricks or Modular Bricks:

To have uniform size throughout the country, Indian Standard Institution

(ISI) has suggested a uniform brick size and is known as standard brick.

The nominal size of standard brick is 20 cm x 10 cm x 10 cm and actual

size of brick is 19 cm x 9 cm x 9 cm.

Classification of Bricks (As per Quality):

The bricks are classified as per their quality as First Class, Second Class &

Third Class bricks.

Sr.

No. Description 1st Class Bricks 2nd Class Bricks 3rd Class Bricks

1 Moulding Machine & Table Hand & Table Hand

2 Colour &

Burning Uniform red

Uniform Red,

may be slightly

over burnt

May be slightly

over burnt or

under burnt

3 Shape

Sharp, straight

edges, plain

rectangular faces

May have

slightly blunt

edges

May have

distorted round

edges

4

Absorption

of water by

weight

Less than 20 % Less than 22 % Less than 25 %

5 Efflorescence Nil Slight Moderate

6 Compressive

Strength

Greater than 10.5

N/mm2

Greater than

10.5 N/mm2

Greater than 10.5

N/mm2

Prof Asim

Ejaz


FIELD TEST ON BRICKS:

1. The brick should be uniform in shape and should be of standard size when

measured.

2. The brick when broken should show a uniform compact and

homogeneous structure free from voids.

3. Bricks should give clear ringing sound when struck with each other.

4. Bricks should be sufficiently hard such that no impression is left when

scratched with finger nails.

5. The brick should not break into pieces when dropped from a height of 1

m.

6. The brick when soaked in water for 24 hours should not show deposits of

white salts when allowed to dry in shade.

7. A brick should not absorb more than 15% of its weight of water when kept

immersed for 24 hours.

8. The brick should be table moulded, well burnt and free from cracks with

sharp and square edges.

9. The colour should be uniform and bright.

USES OF BRICKS:

1. Bricks are used for the construction of walls.

2. Hallow blocks i.e. bricks with cavities are used in the construction of

walls, as they are very light so very useful for high rise buildings.

3. Bricks are also used for the construction of columns, compound walls,

chimney and other special works.

4. Bricks of good quality i.e. 1st class bricks are used for fencing of wall.

5. Paving bricks manufactured from clay containing large percentage of

iron are used pavements since they resist abrasion.

6. Fire bricks manufactured from fire clay are used as refractory bricks for

lining furnace.

7. Sand-lime bricks are used for decorative work.

Prof Asim

Ejaz


4.1.3 STONES

Stones are naturally occurring compact, solid and massive materials that

make the crust of the earth. Stones are obtained from rocks. Process of taking

out stones from natural rock beds is known as quarrying. Stones are used for

various engineering purposes.

Types of stones: 1. Dressed stones 2. Undressed

stones

1. Dressing of stone: The process of giving a proper shape, size and surface

finish to a raw stone as obtained from the quarry, before it is fit for use in

construction is called Dressing. This is done either manually or

mechanically or in some cases using both the methods.

Methods of stone dressing:

i. Manually: Manually, skilled workmen can work wonders on suitable

type of stones with chisels, hammers and abrasives. Not only they can

give excellent finish and polish but also may do carving and engraving

that can withstand for centuries. The traditional dressing methods applied

in manual dressing are Pitched dressing, Hammer dressing, Chisel

drafting, Rough tooling, Punched dressing, Boasted finish.

ii. Mechanically: Mechanically, special saw-fitted machines can cut slabs,

blocks and any other shape from rough rocks. These are called rock

cutters. The grinding and polishing machines are fitted with wheels or

disc with abrasive capable enough to give polish and fine finish to any

desired degree even on hardest of stones.

USES OF STONES IN CONSTRUCTION:

1. Stones are used as a construction material for foundations, walls, columns

and lintels.

2. Stones are used for face-work of buildings to give good appearance.

3. Thin stone slabs are used as roofing and flooring material. Marble which

is having good appearance is used as flooring material in luxurious

buildings.

4. Stones are used for paving of roads, foot path and open spaces around the

buildings.

Prof Asim

Ejaz


5. Crushed stones are used for production of cement concrete.

6. Crushed stones are also used as ballast for railway track.

7. Aggregate of stone is used as a road metal.

8. Crushed stones with murrom are used to provide base course for roads.

When very smaller pieces of stones are mixed with tar, it forms finishing

coat of roads.

9. Stones are also used in construction of piers and abutments of bridges.

10. Commonly used building stones are Granite, Basalt, Sandstone

Limestone, Marble etc.

CHARACTERISTICS OF GOOD BUILDING STONES:

1. Appearance: It should be of uniform colour and architectural point of

view; these should match with the surroundings.

2. Strength: These should be able to withstand the compression without

getting crushed due to the load of the structure.

3. Structure: These should be either closed grained or crystalline and should

show uniformity of texture.

4. Hardness: These should be able to resist the abrasive forces caused due to

wear and friction.

5. Toughness: Good stone should be tough enough to withstand stresses

developed due to vibrations of machineries and moving load over them.

6. Heaviness: The specific gravity of good building stones should range

between 2.4 to 2.8.

7. Durability: The good stone should be highly resistant to weathering such

as wind and rain.

8. Porosity and absorption: The good stone should not be porous. It should

not absorb water when immersed.

9. Resistance to fire: Stones when exposed to fire should be able to resist

temperature.

10. Dressing: It should be easily carved and dressed. Seasoning: The good

stone should be free from quarry sap.

Prof Asim

Ejaz


4.1.4. AGGREGATES:

Sand and stone chips are collectively known as aggregates.

Classification of Aggregates:

Aggregates can be classified as per,

I) Size:

1. Fine aggregate: The aggregates having size smaller or less than 4.75

mm are classified as fine aggregates. Natural sand or crushed stone

dust is the fine aggregates chiefly used in concrete mix.

2. Coarse aggregate: The aggregates having size more than 4.75 mm are

classified as coarse aggregates. The size of the coarse aggregate used,

depend upon the nature of work. For example, 15 mm to 20 mm is used

for concreting.

Sizes of aggregates:

Fine aggregate: 10 mm, 4.75 mm, 2.36 mm, 1.18 mm, 600 micron, 200

micron, 150 micron.

Coarse aggregate: 10 mm, 12.5 mm, 16 mm, 20 mm, 40 mm, 63 mm.

II) Source:

1. Natural aggregate: They are generally obtained from natural deposit

of sand, gravel and rocks.

2. Artificial aggregate: They are usually produced for some special

purposes. For example: burned expanded clay aggregate for making

lightweight concrete. Some artificial aggregates are by product of

industrial process such as blast furnace slag.

III) - Particle Shape

1. Rounded Aggregate: Full water-worn or shaped by attrition. Not

suitable for concrete.

2. Irregular Aggregate: Naturally irregular or partly rounded by natural

attrition and having rounded edges. Suitable for concrete medium

quality concrete.

3. Angular Aggregate: Possessing well defined edges, roughly plane

faces. Best for concreting.

Prof Asim

Ejaz


4. Flaky & Elongated Aggregate: Angular having small thickness as

compared to width or length. Suitable for only lower grade of concrete.

IV] - Unit weight:

1. Normal weight aggregate: It is usually the natural aggregate for which

the unit weight is between (1500 to 1800) kg/m3.

2. Light weight aggregate: It can be artificial or natural. The artificial

lightweight aggregates are produced as both coarse and fine materials.

They have a lower density due to increase in porosity which results in

an overall lowering of the concrete strength ceiling. Lightweight

aggregates are not as dense as normal weight aggregates (unit weight

less than 1000 kg/m3). Lightweight aggregates can be of natural sources

such as Pumic (a volcanic rock).

3. Heavyweight aggregate: Where concrete of a high density is required,

in radiation shielding for example, heavyweight aggregates can be

used. The unit weight can be larger than 1800 kg/m3. Concrete densities

of 3500-4500 kg/m3 are obtained by using Barytes (a barium sulphate

ore). Even greater concrete densities are obtained using lead shot -

around 7000 kg/m3.

USES OF AGGREGATES:

1. They are used to make concrete aggregates.

2. Aggregates can be used as a road base and coverings and for road

stabilization.

3. To form asphaltic concrete aggregates and other bituminous mixtures.

4. Aggregates can be used as construction fill.

5. They are useful in the manufacture of concrete products such as blocks,

bricks, pipes, etc.

6. They serve as railroad ballast.

7. Aggregates are used in construction to provide drainage, fill voids,

protect pipes, and to provide hard surfaces.

Prof Asim

Ejaz


8. They are also used in water filtration and sewage treatment processes.

Water will percolate through a trench filled with aggregate more

quickly than it will through the surrounding soil, thus enabling an area

to be drained of surface water.

9. This is frequently used alongside roads in order to disperse water

collected from the asphalt surfacing.

4.1.5 REINFORCING STEEL:

Steel bar which are reinforced into the concrete to sustain the tension and

increases its strength is called as reinforced steel. Reinforcing steel consists

of bars, usually circular in cross-section.

Grades of reinforced steel:

The grades of steel depend upon the percentage of carbon are as

follows:

These are available in three different grades as Fe-250, Fe-415, and Fe-

500.

'Fe' refers to ferrous metal and the number refers to the specified

guaranteed yield stress in N/mm2.

It is an alloy of iron and carbon containing carbon from 0.25% to 1.25%.

Steels are highly elastic and ductile. It has high tensile strength, it

develops good bond with concrete.

Classification / Types of Steel:

Based on the physical and mechanical properties, the following are the

types of Reinforcing Steel.

1. M.S (Mild Steel): Mild Steel is used as structural and Non-structural

steel in the form of various sections like I-section, channel, angled, flat

and also in the form of round bars as reinforcement in concrete. It is

designated as Fe-250 due to the yield strength of 250 N/mm2.

2. Tor Steel: These bars are usually of steel which do not possess a well-

defined yield point. These bars have low ductility and low bend ability.

Tor steel is extensively used as reinforcement in R.C.C. work. It is

Prof Asim

Ejaz


available in two grades, Fe-450 & Fe-500 and a variety of diameters

ranging from 8 mm to 40mm.

3. TMT: Thermo-Mechanically Treated steel also known as TMT steel can

be described as new generation-high-strength steel having superior

properties such as weld ability, strength, ductility and bend ability

meeting highest quality standards at international level.

4.1.6 STRUCTURAL STEEL:

Structural steel is steel construction material manufactured in steel

mills with a specific shape, size or cross section and certain standards

of chemical composition and mechanical properties.

1. Steel bars:

a) Round bars: These are available in lengths of 10 to 12 m. To strengthen

the plain concrete, mild steel bars are used.

b) Square section bars: Square section of 5 to 32 mm are most common

which are used as railing in buildings for grill work and gates.

c) Deformed bars: Certain special type of bars having slight projections or

helical ribs on their surface, are called Deformed Bars which are widely

used as reinforcement in all type of R.C.C. construction.

2. Plates:

The plates are used as webs and flanges for beams, columns, and

column bases.

3. Flats:

These are similarly rolled as plates but are larger and have shorter

width.

These are used in railings, grill work and built-up sections.

4. Standard sections:

i) Angle sections: They are used in bridges, trusses and general structural

steel work.

ii) Channel Section: these are used for columns, trusses, roof purlins,

composite beam and girders’

iii) I section: They are used for column, beam in building. They are also

used as bridge girders.

Prof Asim

Ejaz


iv) T-Section: They are widely used for steel roof trusses and to form built-

up section.

v) H-Section: They are used for columns.

vi) Tabular Section: These are used for columns, trusses and pipes.

Fig: Different Steel Section

4.1.7 STRUCTURAL GLAZING

Now a days, in structural glazing; the glass claddings works is preferably

adopted in building construction, since it fulfills the various functional

requirements of building such as lighting, heat retention etc. with visual

impact creation. Tempered safety glass and vitrified glass are used for

glass cladding work.

Characteristics of glass claddings in case of structural glazing:

1. It is totally safe.

2. It is aesthetical and recyclable.

3. It is energy saver and time saver as per the constructional aspect is

concerned.

4. There are no flaws of plaster and paint.

5. It has attractive colours.

Advantages of glass claddings in structural glazing:

1. Its use fulfills the architectural view for the external decoration and

adds beauty to the building

2. Using glass in interior of the building saves the space inside the

building.

Prof Asim

Ejaz


3. Glass cladding in building fulfill the functional requirements such as

lighting, heat retention, thermal insulation, and water proofing and

energy conservation.

Disadvantages of glass claddings in structural glazing:

1. It is very costly and may increase the cost of construction work.

2. Use of glass also enhances the cost of security.

3. It is also unsafe for earthquake prone area.

4.2 CONCRETE TYPES:

Different types of concrete are PCC, RCC, Pre-Stressed, Pre-Cast and

Ready Mix Concrete (RMC)

Concrete:

Concrete or cement concrete is the most important artificial building

material being commonly used in present day construction. Cement

concrete is an artificial product obtained by hardening of mixture of

cement, sand and aggregate with water in pre-determined proportions.

The hardening of cement-concrete is due to chemical reaction between

cement and water and the process is called ‘setting’.

1. Plain Cement Concrete (P.C.C):

The concrete obtained by mixing cement sand aggregate with an adequate

quantity of water. P .C.C. is very strong in compression and weak in

tension. It has good weathering resistance and is impervious. It has good

resistance to abrasion & is hard & durable.

Uses of P.C.C.:-

1. As bed concrete below the wall footings, column footings and on walls

below beams.

2. As sill concrete to get a hard and even surface at window and ventilator

sills.

3. As coping concrete over the parapet and compound walls.

4. For flagging the area around the buildings.

5. For making pavements.

6. It is used in mass concrete work in construction of gravity dams and

retaining wall.

7. For making tennis courts, basketball courts etc.

2. Reinforced Cement Concrete (R.C.C):

It is obtained by reinforcing steel in the mixture of cement, sand and

coarse aggregate with an adequate quantity of water. R.C.C. is equally

strong in compression and tension. It is hard, durable and can bear all type

Prof Asim

Ejaz


of stresses. R.C.C. is used for columns, beams, slabs, foundations,

retaining wall, water and oil tanks, road pavements, concrete pipes.

Uses of R.C.C.:

1. R.C.C. is used for construction of structural elements such as beams,

columns and slabs.

2. R.C.C. is used for the construction of water tanks, storage bins, tall

chimneys, towers etc.

3. R.C.C is used in making raft foundations and pile foundations.

4. R.C .C. is used in the construction of bridges, marine structures, multi-

storied buildings and many other civil engineering works.

5. The common structural elements in a building where R.C.C. is used are

footing, columns, and beams, lintels chajjas, roof, slabs and stairs.

6. R.C.C. is used for the construction of storage structures like water

tanks, dams, silos, bunkers.

7. They are used for the construction of bridges, retaining walls, docks,

harbours, under water structures,

8. R.C.C. is used for building tall structures like multi-storey buildings,

chimneys, towers.

9. R.C.C. is used for paving high ways, city roads, and airports.

10. R.C.C. is used in atomic plants to prevent radiation. For this purpose

R.C.C. walls built are as thick as 1.5 m to 2.0 m.

3. Pre-stressed Concrete

It is a modification of reinforced concrete, which not only eliminates

the weakness of concrete in tension hut also makes it possible to take

full advantage of compressive strength of concrete.

The concrete is subjected to compressive stresses, before the external

loads are applied by inducing tensile stresses in the reinforcement to

counteract tensile stresses in the concrete caused by external loads.

There are two methods of pre-stressing

a) Pre-tensioning b] Post-tensioning.

Uses of Pre-stressed Concrete:

1. Pre-stress concrete girders are used in bridge construction.

2. The large span beams are possible with pre-stressed concrete.

3. Railway sleepers and electric poles are examples of pre-stress concrete.

4. Used in construction of nuclear power station, steel plants, piers and

transmission poles.

Prof Asim

Ejaz


4. Precast Concrete:

Individual concrete units or members of various types which are cast

in separate form before they are placed in a structure arc known as

precast concrete members.

When a large number of components of similar dimensions are

required, the best option is to use precast concrete units produced in

a factory.

Uses of Precast Concrete:

1. In the production of building components like beams, columns, slabs,

stairs, water tanks, partition walls, septic tank, step units, panels,

manholes, water supply and drainage pipes, fencing posts.

2. In the production of industrial elements such as girders, trusses,

frames, dome etc.

3. In the production of electric poles, piles, caissons, road dividers, traffic

barriers etc.

5. Ready Mix Concrete (R.M.C.)

Ready Mix concrete is a type of concrete that is manufactured in a

factory or batching plant, according to a set recipe and then delivered

to a work site by truck mounted transit mixers. This results in a precise

mixture allowing specialty concrete mixtures to be developed and

implemented on construction sites.

Ready Mixed Concrete is manufactured under computer-controlled

operations and transported and placed at site using sophisticated

equipments and methods.

Uses of R.M.C.:

1. Better quality concrete is produced. ·

2. Elimination of procurement/hiring of plant and machinery.

3. Elimination of storage space for basic material at site.

4. Wastage of basic materials is avoided.

5. Time required is greatly reduced.

4.3 USE OF VARIOUS ECO-FRIENDLY MATERIALS IN CONSTRUCTION:

Eco-friendly Materials: Eco-friendly materials arc the product that has

been designed to do the least possible damage to the environment

and human health when compared with competing products that

serve the same purpose. Eco-friendly products / materials have become

a prime necessity to save the environment.

Prof Asim

Ejaz


Properties of Eco-friendly materials:

1. Biodegradable

2. Reuse / Recycle

3. Energy Efficient

4. Durability & Life span

5. Reduction in pollution

6. Local availability

7. Reuse of waste material

8. Renewable source

Eco-friendly Materials:

1. Stone Dust.

2. R.C.C.-door frame.

3. Marble mosaic tiles.

4. Fly-ash, sand lime bricks.

5. Sun dried bricks.

6. Cement Paint

7. Ferro-cement boards for

doors and window shutters.

8. Precast Concrete blocks.

9. Bamboo, Bamboo based ply-

board.

10. Clay roofing tiles.

11. R.M.C.

12. Gypsum blocks, tiles and

board

QUESTIONS

1) What are the grades of cement? Explain Field tests on Cement.

2) Explain different types of bricks. Also explain various Field tests on

Bricks.

3) Explain Precast Concrete and Ready Mix Concrete.

4) Enlist the different types of Building materials required for the

construction.

5) Explain the uses of bricks.

6) What are the properties of good bricks?

7) What are the types of stones?

8) Explain the uses of stones in construction

9) What are the requirements of good building stones?

10) Enlist different types of cement & explain any five.

11) What are the aggregates? Explain the properties of good aggregates.

12) Enlist the different types of concrete.

13) Explain different types of steel sections with their uses. Also draw neat

sketches.

14) Write short notes on:

Plain Cement Concrete

Pre-stressed Concrete.

Structural Glazing.

Reinforced Cement Concrete

Eco-friendly materials.

Prof Asim

Ejaz

civil engineering prof asim ejazsoil property changes from place to place. the load from the...

Documents