UNIT-I

Basics of Civil Engineering

CIVIL ENGINEERING is a professional engineering discipline that deals with the design,
construction, and maintenance of the physical and naturally built environment, including
works like roads, bridges, canals, dams, and buildings.

Role of Civil Engineers in Society.

 Main role of Civil engineers is in surveying, planning, designing, estimation and
execution of structures.

 To solve different engineering problems with the help of field experience, laboratory
techniques, numerical methods, mathematical models, using computer and
information technology.

 To implement management techniques for better management of man, material,

machine and money.

 To carry out soil investigation for design of foundations of structures.

 To invite tenders and to select contractor for the work.

 To carry out surveying and levelling and fixing the alignments (center-line) of roads,
railways, canals, tunnels, pipes etc.

 To carry out planning of buildings as per its functional needs and also has role in town
and regional planning.

 To carry out the design of structures as per the principles of structural analysis and
design. Civil engineer should ensure that design is safe, durable and economic.

 To supervise the work during execution and to ensure progress of work.

To carry out valuation of land or building for the purpose of finding its sale or purchase price
or taxation.

Various Disciplines of Civil Engineering

 Structural Engineering
 Geo-technical Engineering
 Transportation Engineering
 Hydraulics and Water Resources Engineering
 Environmental Engineering
Structural Engineering

 This Branch of civil engineering deals with structural analysis and design of
structures. Structural analysis is done to calculate stresses in structural components,
on the basis of loads, acting on structures.
 Sections of structural elements like beams, columns, slabs, etc. are designed.
Structural analysis requires much calculation, hence advanced computing software's
are used to carry out structural analysis and design.
 It includes design of reinforced cement concrete ( RCC) and steel structures. Design
of Multistoried buildings, towers, retaining walls, water tanks, bridges requires skills
and knowledge of structural engineering.

Geo-technical Engineering

 Geotechnical engineering is that field of civil engineering which deals with soil
investigation and design of proper foundations of structures.
 Soil investigation includes collection and testing of soil samples.
 Geotechnical engineering includes measurement of soil parameters and safe bearing
capacity. It also includes construction and design of simple foundations, pile
foundations, well foundations, caissons, coffer dams, construction of foundation of
dams, construction of tunnels, sub base of road, earthen dams, earth related
constructions. Sound knowledge of geology and geotechnical engineering is
necessary for construction of earth related structures.

Transportation Engineering

 Transportation means movement of passengers and goods by means of vehicles on

land, ship on water and aircrafts in air.
 Transportation Engineering is that branch of Civil engineering which deals with
planning, designing and construction of roads, bridges, railways, tunnels, harbours,
ports, docks, runways, and airports.
 As for development of any nation good transportation network is of prime
importance. Study of various construction materials used in construction of roads,
traffic engineering are also considered under transportation Engineering.

Hydraulics and Water Resources Engineering

 Water resource engineering means measurements, utilization and development of

water resources for agriculture, municipal and power generation purpose.

 It mainly includes irrigation engineering, design of hydraulic structures like dams,

canals, etc. Water resource engineering deals with planning designing and developing
water resources by constructing several hydraulic structures like dams, barrages,
hydropower stations, canal and pipe networks etc.
  It also includes watershed planning, water harvesting techniques, soil conservation
and soil reclamation. Hydrology is also a part of water resource engineering.
Hydrology includes study of sources of water, measurement of rainfall, study of
rainfall, runoff, and flood control.

Environmental Engineering

 Environmental Engineering deals with pollution control and public health

engineering. Different types of pollutions are water, air, noise and other pollution.

 Due to large scale industrialization, population growth, rapid urbanization and several
other human activities like construction, mining, transportation, environment gets
polluted.

 Environmental Engineering deals with technologies & facilities which are engaged in
reducing pollution. Environmental engineering includes design, construction and
maintenance of water treatment plant, waste water treatment plant, water distribution
network and sewerage system, it also deals with solid waste management in towns
and cities. Public health engineering includes water treatment, water distribution
network, & solid waste management.

Construction Materials

Building materials are the different types of materials that are used for construction
purposes. Some of the common construction materials include wood,
concrete, steel, cement, bricks, and metal.

CEMENT

 Cement is a fine, soft powder used as a binder because it hardens after contact with
water. It is produced from a mixture of limestone and clay that's charred and then
ground up.

 Type 1 is ordinary Portland cement (OPC), which is a general-use material. Type 2

has moderate sulfate resistance, and its MH variant is moderately resistant to heat of
hydration. It's used in structures that will come into contact with sulfate in water or
soil. Type 3 cement is an extra rapid hardening cement.

 A mixture of limestone and other raw materials like argillaceous, calcareous, and
gypsum is prepared and then grinded to prepare OPC (Ordinary Portland
Cement). PPC (Portland Pozzolana Cement) is prepared by adding Pozzolanic
materials to OPC.
AGGREGATE

 Aggregate is a landscaping term that's used to describe coarse to medium grain

material. The most common types of aggregate that are used in landscaping
include: crushed stone, gravel, sand, and fill. Varying in material and stone size, each
type can have its own purpose when it comes to landscaping projects

 Coarse aggregates refer to irregular and granular materials such as sand, gravel, or
crushed stone, and are used for making concrete. In most cases, Coarse is naturally
occurring and can be obtained by blasting quarries or crushing them by hand or
crushers. It is imperative to wash them before using them for producing concrete.
Their angularity and strength affect the concrete in numerous ways. Needless to say,
the selection of these aggregates is a very important process.

The size, shape, texture, and hardness of coarse aggregates are used in their classification.
Analysis of these characteristics will ensure proper use of aggregates in construction projects.

 Particle size: A sieve test is performed to determine the particle sizes in an aggregate
sample. This grading of the aggregate is done in accordance with ASTM 136. This
procedure refers to the distribution of particle sizes. An aggregate sample is shaken
through a series of sieves stacked on top of each other with the sieve with the smallest
opening on the bottom. The coarse aggregate will have most of its particles remaining
in the No. 4 fine sieve with a 4.75 mm (0.1870 in.) opening or in a larger sieve.

 Particle shape: The particle shape of an aggregate is based on compactness. Particles

can be classified as spherical, flat (flaky) or elongated. The higher the compactness
the more spherical or cubical (irregular) the shape. Flaky aggregates are flat, while
elongated aggregates are longer. Both flaky and elongated aggregates are less
compact. Angularity deals with how sharp or pointy the edges of an aggregate are.

 Particle surface texture: The degree of surface roughness of an aggregate is called

surface texture. An aggregate particles can be classified as rough, granular,
crystalline, smooth, or glassy depending on the condition of the surface texture.

 Particle hardness: Coarse aggregates can be obtained from crushing natural stone. The
hardness or strength of the coarse aggregate produced, depends on the strength of the
stone used in aggregate production. Coarse aggregates are tested for abrasion and
impact resistance which is their ability to resist being broken down by friction or
shattering. This test is important because a good coarse aggregate must resist
degradation in the handling, stockpiling, and mixing processes. In this test coarse
aggregates are placed in a steel drum with steel balls and the drum is rotated for a
number of revolutions. After this a sieve test is preformed to analyze the percentage
of coarse aggregate worn away.

Fine Aggregate
  The size of fine aggregates is defined as 4.75mm or smaller. That is, aggregates
which can be passed through a number 4 sieve, with a mesh size of 4.75mm. Fine
aggregates include things such as sand, silt and clay. Crushed stone and crushed
gravel might also fall under this category.

 Fine aggregates are used in projects where a smooth yet highly compacted surface
is desired. Fine aggregates are ideal for use underneath pavers, path fines, track
fines, athletic infield material and can even be used as a soil amendment.

Role of Fine Aggregate in Concrete Mix

Fine aggregates are the structural filler that occupies most of the volume of the concrete mix
formulas. Depending on composition, shape, size and other properties of fine aggregate you
can have a significant impact on the output. The role of fine aggregate can be described in
few points:

 Fine aggregates provide dimensional stability to the mixture

 The elastic modulus and abrasion resistance of the concrete can be influenced with
fine aggregate

 Fine aggregates quality also influence the mixture proportions and hardening
properties

 The properties of fine aggregates also have a significant impact on the shrinkage
of the concrete.

BRICKS

A brick is building material used to make walls, pavements and other elements in masonry
construction. Traditionally, the term brick referred to unit composed of clay, but it is now
used to denote any rectangular units laid in mortar. A brick can be composed of clay-bearing
soil, sand and lime, or concrete materials.

Bricks are still in common use today for the construction of walls and paving and for more
complex features such as columns, arches, fireplaces and chimneys

In India, clay is burned in a kiln to create bricks. Bricks that are standard size are 190 x 90 x
90 mm without mortar. The nominal size is defined as 200 x 100 x 100 mm for bricks with
mortar (10 mm).

The bricks used in construction must be free from defects in order to ensure the strength and
stability of the structure built using those bricks. The causes of defects in bricks and common
types of defects in bricks are:

1. Overburning
 2. Underburning

3. Bloating

4. Black Core

5. Efflorescence

6. Chuffs

7. Checks or Cracks

8. Spots

9. Blisters

10. Spalling

11. Lamination

12. Lime Blowing

CEMENT CONCRETE

Cement concrete means a mixture of cement, sand and coarse materials, which latter shall be
of broken stone or other approved material, the size to be approved.

Cement is mainly used as a binder in concrete, which is a basic material for all types of
construction, including housing, roads, schools, hospitals, dams and ports, as well as for
decorative applications (for patios, floors, staircases, driveways, pool decks) and items like
tables, sculptures or bookcases.

Put simply, concrete is a mixture of cement, water, and aggregates (like sand and gravel) that
hardens over time to create a solid, strong substance. It's used in all sorts of construction
projects because it's affordable, durable, and can be moulded into nearly any shape.

As these properties affect the hardened compressive strength and durability of concrete
(resistance to freeze-thaw), the properties of workability (slump/flow), temperature, density
and age are monitored to ensure the production and placement of 'quality' concrete.

STEEL

Steel is an alloy of iron and carbon. It is highly elastic, ductile, malleable and weldable. Steel
has high tensile and compression strength and also stands wear and tear much better.

Steel is used because it binds well to concrete, has a similar thermal expansion coefficient
and is strong and relatively cost-effective. Reinforced concrete is also used to provide deep
foundations and basements and is currently the world's primary building material.
lain carbon/mild steel is the most common type of steel used for building construction, and its
hallmark is its durability. Not only is it able to endure heavy pressure and impact with no
cracks, but it is also flexible and ductile. There is also the variant of low carbon steel

Construction Steel work involves marking out, cutting, assembling, repairing and maintaining
steel structures such as buildings and bridges using heavy plant and lifting equipment and a
range of welding processes.

The steel generally used in RCC work is mild steel. It is very strong and durable. Mild steel is
extremely flexible despite its strength, which keeps it from cracking when bent.

Classifications of prefabricated systems

The first three types are mainly classified according to their degree of precast elements used
in the construction. For example brick is small unit of pre casted material and used in
buildings. This is called as small prefabrication and the degree of precast element is very low.
Medium prefabrication:

Suppose the roofing systems and horizontal members are provided with pre casted elements.
These constructions are known as medium prefabricated construction. Here the degree of
precast elements is moderate.

Large prefabrication: In large prefabrication most of the members like wall panels,
roofing / flooring systems, beam sand columns are prefabricated. Here the degree of precast
elements is high. One of the main factors which affect the factory prefabrication is transport.
The width of the road, mode of transport vehicles are the factors which determines the
prefabrication which is to be done on site or in factory. Suppose the factory is situated far
away from the construction site and the vehicle needs to cross congested traffic areas with
heavy weighing elements the cast in site prefabrication is preferred. Even though the same
condition as the cast in site prefabrication is preferred only when umbers of houses are more
for small elements the conveyance is easier with normal type of lorry and tractors. We can
adopt factory or off-site prefabrication for this type of construction.

Open system of prefabrication: In the total prefabrication systems, the space frames are
casted as a single unit and erected at the site. The wall fitting and other fixing are done on
site. This type of construction is known as open system of prefabrication. Closed system of
prefabrication: In this system the whole things are casted with fixing and erected on their
position. Partial prefabrication: In this method of construction, the building elements required
are precast and then erected. Since the casting of horizontal elements (roof / floor) often take
more time due to erection of frame work, the completion of the building is delayed and hence
this method is restored. In most of the building sites, this method is popular, so in industrial
buildings where the elements have longer spans. Use of double tees, channel units, cored
stabs, slabs, hyperboloid shells, etc, are some of the horizontal elements used. This method is
efficient when the elements are readily available and the building has reached the roof level.
The delay caused due to erection of framework, delay due to removal of framework is
eliminated completely in this method of construction suitable for any type of building
provided lifting and erection equipment’s are available. Total prefabrication: Very high
speeds can be achieved by using this method of construction. The method can be employed
for frame type of construction or for panel type; the total prefabrication is done on-site or off-
site. The choice of the two methods depend on the situations when the factory produced
elements are transported and erected on site, we call it off-site prefabrication. If this method
is to be adopted we should have a very good transportation facility for the products to be
transported to the site of construction. If the elements are cast near the building site and
erected, the transportation of elements can be eliminated, but we have to consider the space
availability for establishing such facilities though it is temporary. modular coordination
Modular coordination means the interdependent arrangement of a dimension based on a
primary value accepted as a module. The strict observance of rules of modular coordination
facilitated, 1. Assembly of single components into large components. 2. Fewest possible
different types of component. 3. Minimum wastage of cutting needed. Modular coordination
is the basis for a standardization of a mass production of component. A set of rules would be
adequate for meeting the requirements of conventional and prefabricated construction. These
rules are adaptable for, a. The planning grid in both directions of the horizontal plan shall be
1. 3m for residential and institutional buildings, 2. For industrial buildings, 15m for spans up
to12m 30m for spans between 12m and18m 60m for spans over18m The centre lines of
load bearing walls shall coincide with the grid lines. b. In case of external walls the grid lines
shall coincide with the centre line of the wall ora line on the wall 5 cm from the internal face
of the wall. c. The planning module in the vertical direction shall be 1m up to and including a
height of2.8m. d. Preferred increments for the still heights, doors, windows and other
fenestration shall be 1m. e. In case of internal columns the grid lines shall coincide with the
centre lines of columns. e. In case of external columns, the grid lines shall coincide with the
centre lines of the columns in the storey or a line in the column from the internal face of the
column in the topmost storey. A basic module can be represented as module and for larger
project modules are represented Mp. For eg: For a project module in horizontal coordination,
the component can be of 30cm and for vertical component size be of 10cm. The storey height
is fixed between finished floor levels as 2.8m and if the thickness of slab is