BASIC OF CIVIL ENGINEERING (TCE

101/201)

UNIT- 3 (SYLLABUS)
CIVIL ENGINEERING MATERIALS
• Importance, properties, uses and quality tests of Timber
• Importance, properties, uses and quality tests of bricks
• Importance, properties, uses and quality tests of cement
• Importance, properties, uses and quality tests of aggregates
• Importance, properties, uses and quality tests of concrete
 Timber
Wood is one of the most important engineering material. Wood has
been classified in two categories:
(i) Fuel- Wood which is used as building material.
(ii) Timber-Wood which is used for engineering construction
Timber has many advantages due to which it is preferred over many
other building materials.
It is easily available and easy to transport and handle
Has more thermal insulation, sound absorption and electrical resistance
as compared to steel and concrete
Wood is a good absorber of shocks and so is suitable for construction
work in hilly areas which are more prone to earthquakes
can be easily worked, repairs
 Timber
CLASSIFICATION OF TREES:
Endogenous tress: Trees grow endwards, e.g. palm, bamboo, etc.
Exogenous trees: Trees grow outwards and are used for making
structural elements. They are further subdivided as conifers and
deciduous.

Conifers: are evergreen trees having pointed needle like leaves, light
in colour, resinous and light weight e.g. deodar, chir, fir, kail, pine.
Decidous: trees have flat board leaves, they yield hard wood and
are non-resinous, dark in colour and heavy weight. e.g. oak, teak,
shishum, poplar and maple.
 Timber
STRUCTURE OF TIMBERS:
• Pith: Innermost central portion of tree
having dark brown color
• Heart wood: Around the pitch, a layer of
dark color wood, which is dense and has
compact structure.
• Sap Wood: Raw wood layer over heart
wood, yellowish in color, can be easily
decayed
• Cambium Layer: Below the bark, there
is a thin film of soft wood
• Medullary rays: Thin fibers which
extends from the pith outwards. The
function of these fibers is to hold annual
rings together
• Bark: Outermost cover of stem.
 Timber
CHARACTERISTICS OF A GOOD TIMBER:
The principal characteristics of timber of are strength, durability and
finished appearance.
• Narrow annual rings, closer the rings greater is the strength.
• Compact medullary rays.
• Dark color.
• Uniform texture.
• Sweet smell and a shining fresh cut surface.
• When struck sonorous sound is produced.
• Free from the defects in timber.
• Heavy weight.
 Timber
SEASONING OF TIMBER:
Timber cut from freshly felled trees is too wet for normal use and is
dimensionally unsuitable.
Seasoning is the process of reducing the moisture content (drying) of
timber in order to prevent the timber from possible fermentation and
making it suitable for use.
It is the process of removing the sap and reducing the moisture.
Advantages of seasoning of timbers:
Reduce the shrinkage and warping after placement in structure.
Increase strength, durability and workability.
Reduce its tendency to split and decay.
Make it suitable for painting.
Reduce its weight.
 Bricks
Bricks are the most commonly used construction material. Bricks are
prepared by molding clay in rectangular blocks of uniform size and
then drying and burning these blocks. In order to get a good quality
brick, the brick earth should contain the following constituents:
Clay Sand
• When mixed with water forms plastic • Prevents shrinkage, warping and
mass. cracking of clay products
• Can be molded in any desired shape. • Gives strength to brick
• Percentage of clay is 20-30% by weight • Percentage of sand is 40-60 %
Iron oxide
Lime
• When brick earth is heated it gives red
• Acts as a flux and forms calcium
color to bricks
silicate when heated at high
• Helps in melting the sand at lower
temperature.
temp.
• Prevents shrinkage and cracking
• Quantity is 8-10% (If excess bricks will
• But tends to expand and crack the
turn blackish If less then color will be
brick when used in excess
yellowish)
 Bricks

The following are some harmful ingredients which may be present in

brick earth

Pebbles or Grit Lime stone

In the presence of pebbles, grit Limestone after burning will form
• Clay will not mix thoroughly calcium oxide and when come in
• Brick after burning will not contact with water it will slake and
have uniform texture brick will be damaged

Reh or Kallar Vegetable roots etc

• Mixture of sodium sulphate, • Causes difficulty in moulding of
calcium chloride and sodium bricks
carbonate prevents brick from • Causes hollowness in bricks and
burning properly bricks become more absorbent
• Causes plaster to peel off
 Bricks
Size and Weight of Bricks:

9 cm
• Indian Standard size of brick:
19 cm X 9 cm X 9 cm

• Nominal size of brick:

20 cm X 10 cm X 10 cm (with mortar thickness)

• Weight of metric brick:

3 kg

• 500 bricks will be required for 1 cubic metre of

masonary.
 Bricks

Characteristics of good Bricks:

• Should have regular shape and size

• Should have smooth surfaces, sharp and straight edges
• Should have uniform brick red color
• Uniform texture
• Should not absorb more than 1/6 of its weight of water when
immersed in water for sixteen hours
• Should have good strength. Crushing strength of ordinary bricks
is 50-70 kg/cm2
 Bricks
Manufacturing of Bricks:
It involves four different operations:
• Preparation of earth
• Moulding
• Drying
• Burning
 Bricks
Classifications of Bricks:
After burning of bricks, they can be classified into
following four types:
(1) First class bricks
(2) Second Class bricks
(3) Third class bricks
(4) Overburnt bricks
(1) First class bricks
• These bricks are table moulded and of standard shape and they are burnt in kilns.
• The surface and edges of the bricks are sharp, square, smooth and straight.
• They comply with all the qualities of good bricks.
• These bricks are used for superior work of permanent nature.
(2) Second class bricks
• These bricks are ground moulded and they are burnt in kilns.
• The surface of these bricks is somewhat rough and shape is also slightly irregular.
• These bricks may have hair cracks and their edges may not be sharp and uniform.
• These bricks are commonly used at places where brick work is to be provided with a coat
of plaster.
 Bricks
Classifications of Bricks:
(3) Third class bricks
• These bricks are ground moulded and they are burnt in clamps.
• These bricks are not hard and they have rough surfaces with irregular and distorted
edges.
• These bricks give dull sound when struck together.
• They are used for unimportant and temporary structures and at places where rainfall is
not heavy.
(4) Overburnt bricks
• These are over burnt bricks with irregular shape and dark colour.
• These bricks are used as aggregate for concrete in foundations, floors, roads etc, because
of the fact that the over burnt bricks have a compact structure and hence they are
sometimes found to be stronger than even the first class bricks.
 Bricks
Inspection and testing of Bricks:
(1) The bricks should be free from flaws and cracks.

(2) The length, height and width of bricks should be properly checked and verified.

(3) Hardness test: In this test a scratch is made on brick surface with a hard thing. If
that doesn’t left any impression on brick then that is good quality brick.

(4) Soundness test: In this test two bricks are held by both hands and struck with
one another. If the bricks give clear metallic ringing sound and don’t break then
those are good quality bricks.

(5) Structure test: In this test a brick is broken or a broken brick is collected and
closely observed. If there are any flows, cracks or holes present on that broken
face then that isn’t good quality brick.
 Cement
Introduction
Cements in a general sense are adhesive and cohesive materials which are
capable of bonding together particles of solid matter into a compact durable
mass.

Chemical composition of raw materials:

 Cement
Manufacturing of cement:
Calcareous and argillaceous raw materials are used in the manufacture of
Portland cement.
The calcareous materials used are cement rock, limestone, marl, chalk and
marine shell. The argillaceous materials consist of silicates of alumina in the
form of clay, shale, slate and blast furnace slag.
Cement can be manufactured either by DRY process or WET process.
DRY PROCESS
•The dry process is adopted when the raw materials are quite hard.
•The process is slow and the product is costly.
•Limestone and clay are ground to fine powder separately and are mixed.
•Water is added to make a thick paste. The cakes of this paste, which contain about 14 per
cent of moisture, are dried and are charged into rotary kiln.
•The product obtained after calcination in rotary kiln is called clinker. The clinker is obtained as
a result of fusion at a temperature of about 1400°- 1500°C.
•Because ferric oxide has lower melting point than the other oxides, it acts as a flux.
•Clinker is then cooled and ground in tube mills where 2-3% gypsum is added to slow down
setting time.
Cement
 Cement
Manufacturing of cement:
WET PROCESS
•The operations in the wet process of cement manufacture are mixing, burning and
grinding.
•The crushed raw materials are fed into ball mill and a little water is added.
•On operating the ball mill, the steel balls in it pulverize the raw materials which
form a slurry with water.
•This slurry is passed to silos (storage tanks), where the proportioning of the
compounds is adjusted to ensure desired chemical composition.
•The corrected slurry having about 40 per cent moisture content, is then fed into
rotary kiln where it loses moisture and forms into lumps or nodules.
•These are finally burned at 1500-1600°C. The nodules change to clinker at this
temperature.
•Clinker is cooled and then ground in tube mills. While grinding the clinker, about 3
per cent gypsum is added.
 Cement

WET PROCESS
 Cement
Types of cement:
(a) Ordinary portland cement (OPC):
OPC is prepared in three grades on the basis of compressive strength at 28 days as
Grade 33, Grade 43 and Grade 53. The grade of cement indicates its mortar cube
compressive strength in N/mm2 at 28 days.
(b) Rapid hardening portland cement :
•It has high lime content. The basis of application of rapid hardening cement (RHC) is
hardening properties and heat emission rather than setting rate.
•RHC attains same strength in one day which an ordinary cement may attain in 3
days. However, it is subjected to large shrinkage and water requirement for
workability is more.
•The cost of rapid hardening cement is about 10 per cent more than the ordinary
cement.
•suitable for repair of roads and bridges and when load is applied in a short period
of time.
 Cement
Types of cement:
(c) High alumina cement:
• The alumina content should not be less than 32%.
• It attains strength in 24 hours, high early strength, high heat of hydration and
resistance to chemical attack.
• It should not be used in places where temperature exceeds 18°C.
(d) Portland slag cement :
• It is manufactured by intimately intergrinding a mixture of Portland cement
clinker and granulated slag with addition of gypsum or calcium sulphate
• The slag constituent in the cement varies between 25 to 65 per cent.
• This cement can be used in all places where OPC is used. However, because of its
low heat of hydration it can also be used for mass concreting, e.g., dams,
foundations, etc.
(e) Portland puzzolona cement:
• It is manufactured by grinding Portland cement clinker and puzzolana (usually fly
ash 10-25% by mass of PPC).
• Puzzolana (burnt clay, shale, or fly ash) has no cementing value itself but has the
property of combining with lime to produce a stable lime-puzzolana compound.
 Cement
Field tests of cement:
There are four field tests may be carried out to as certain roughly the quality of
cement. There are four types of field tests to access the colour, physical property,
and strength of the cement.

1) COLOUR 2) PHYSICAL PROPERTIES

• The colour of cement should be uniform. • Cement should feel smooth
• It should be typical cement colour i.e. when touched between fingers.
grey colour with a light greenish shade. • If hand is inserted in a bag or
heap of cement, it should feel
cool.

3) PRESENCE OF MOISTURE 4) STRENGTH

• Cement should be free from lumps. • A thick paste of cement with
• A handful of cement is thrown on a water is made on a piece of
bucket filled with clean water. If it sinks thick glass and it is kept under
immediately shows the moisture already water for 24 hours. It should
present in cement set and not crack.
 Aggregates
INTRODUCTION:
• Aggregates are the materials basically used as filler with binding material
in the production of mortar and concrete.
• They are derived from igneous, sedimentary and metamorphic rocks or
manufactured from blast furnace slag, etc.
• They occupy 70-80 per cent of the volume and have considerable
influence on the properties of the concrete.
• The coarse aggregate form the main matrix of concrete and the fine
aggregate form the filler matrix between the coarse aggregate.
 Aggregates
CLASSIFICATION OF AGGREGATES:
AGGREGATE AGGREGATE COMPONENT PARTICLE SIZE RANGE AND
DESCRIPTION
Coarse aggregates Gravel Coarse: 80 mm to 20 mm sieve
(80 mm to 4.75 Fine: 20 mm to 4.75 mm sieve
mm)
Fine aggregates Coarse: 4.75 mm to 2 mm sieve
Sand Medium: 2 mm to 425 micron
Fine: 425 micron to 75 micron
Silt Particles passing through 75 micron
sieve and retaining on 2 microns sieve
Clay/ Organic matter Particles smaller than 2 micron

•If particle size is greater than 80 mm and upto 30 cm, they are termed as COBBLE.
• If particle size is more than 30 cm, then BOULDERS.
 Aggregates
LIST OF IS CODES RELATED TO TESTING OF AGGREGATES:

TESTS FOR AGGREGATES WITH IS CODES

Property of aggregate Type of test Test method
Crushing strength Crushing test IS : 2386 (part 4)
Hardness Los Angeles abrasion test IS : 2386 (Part 5)
Toughness Aggregate impact test IS : 2386 (Part 4)
Durability Soundness test IS : 2386 (Part 5)
Shape factors Shape test IS : 2386 (Part 1)
Adhesion to bitumen Stripping value of IS : 6241-1971
aggregate
 Admixtures
Admixtures are artificial or natural materials added to the concrete besides cement,
water and aggregate to improve certain property of concrete during casting or
setting or service stage.
Purpose of using admixtures
•To improve workability of fresh concrete
•To improve durability by entrainment of air
•To reduce the water required
•To accelerate setting & hardening & thus to produce high early strength
•To aid curing
•To impart water repellent / water proofing property
•To offset / reduce shrinkage during setting & hardening
•To cause expansion of concrete and automatic prestressing of steel
•To aerate mortar / concrete to produce a light-weight product

• Types of admixtures

Chemical admixtures - Accelerators, Retarders, Water-reducing agents, Super

plasticizers, Air entraining agents etc.
Mineral admixtures - Fly-ash Blast-furnace slag, Silica fume and Rice husk Ash etc
 Mortar
MORTAR:
Building mortars are mixtures used for the jointing of bricks, stones, blocks, etc.
Mortar may be defined as a paste (capable of setting and hardening) obtained by
adding water to a mixture of fine aggregates such as sand and binding material, e.g.,
clay, gypsum, lime or cement or their combinations.

CLASSIFICATION OF MORTAR:
On the basis of binding material
Cement mortar are prepared from Portland cement or its varieties, sand and water.
Lime Mortar are mixture of air hardening lime or hydraulic lime, sand and water.
Gypsum Mortar are prepared from gypsums or anhydride binding materials.
Mud Mortar are prepared from clay nodules and are used in construction of houses
for poor and temporary construction works.
Composite mortar may be surkhi-mortar (surkhi, lime and water), lime-surkhi-
sand mortar, cement-lime mortar and cement-clay mortar.
 Plywood
PLYWOODS:
Plywood are thin boards made by gluing together thin sheets of
veneers, under pressure. Veneers are thin layers of soft wood 2mm to
6mm in thickness, sliced in continuous thin sheets.
• Two sheets of veneers of high quality are used on face and back of plywood are
called faces.
• Intermediate veneers of inferior quality are called cores.
• Plywood is lighter in weight, better in appearance, can bent in desired shapes
 Glass
Glass is an amorphous substance having homogeneous texture. It is a hard,
brittle, transparent or translucent material. It is the most common material
glazed into frames for doors, windows and curtain walls.
Constituents in glass:
The raw materials used in manufacturing glass are sand, lime and soda or potash which
are fused over 1000° C. Oxides of iron, lead and borax are added to modify hardness,
brilliance and colour.
Manufacturing of glass:
Melting: The raw materials — lime, soda and sand — separately cleaned, ground, sieved
in definite proportion and mixed with water are fused in a furnace. The charge in the
first stage melts, forming a bubbly, sticky mass, and as the temperature is raised (1100°
C–1200° C) it turns to a more watery liquid and the bubbles rise to the surface. Heating
is continued till the molten mass is free from bubbles and glass balls. As the glass cools
(800° C), it is ready to be drawn or floated to its desired thickness and size.
Forming and shaping: Glass articles are allowed to cool under room temperature by
passing through different chambers with descending temperature. If cooled rapidly, the
glass being bad conductor of heat under the process of annealing. After annealing the
glass articles are cleaned, ground, polished, cut and sand blasted.
 Plastics
PLASTICS:
Plastics are made from resin with or without fillers, plasticisers and pigments.
Plastics are replacing glass, ceramics and other building materials due to the low
temperature range in which they can be brought to the plastic state and the
consequent ease of forming and fabrication and also for their low cost and easy
availability.
CLASSIFICATIONS OF PLASTICS:
1) Thermoplastics: The thermoplastic variety softens on heating and hardens on
cooling, i.e., their hardness is a temporary property subjected to change with
rise or fall of temperature and can be brought again to plastic stage on
heating. These are formed by addition polymerisation and have long chain
molecular structure. They can be remoulded, for use, as many times as
required.
2) Thermosetting plastics: Thermosetting plastic cannot be reused. They require
great pressure and momentary heat during moulding and finally get hardened
on cooling. The chemical reaction in this process cannot be reversed. Once
solidified they cannot be softened. Compared to thermoplastics, they are
hard, strong and more brittle.
 Concrete
DEFINITION:
Concrete is the composite material that is created by mixing binding material
(cement) along with the aggregate (sand, gravel), water, admixtures, etc in specific
proportions.

COMPOSITION OF CONCRETE MIX:

• Binding materials (cement):When water is mixed with the cement, a paste is
created that coats the aggregates within the mix. The paste hardens, binds the
aggregates, and forms a stone-like substance.
• Coarse aggregate (stone chips): Acts as filler material and provide volume to
concrete.
• Fine aggregate (sand): Acts as filler material in concrete and make it more
compact. Reduces the shrinkage of concrete.
• Water: Helps in hydration of cement and and uniform mixing of ingredients
• Admixture (e.g. Pozzolana): enhances properties of concrete.
 Concrete
DESIRED PROPERTIES OF CONCRETE:
• The concrete mix is workable. It can be placed and consolidated properly.
• Desired qualities of the hardened concrete are resistance to freezing and
thawing and deicing chemicals, water tightness (low permeability) , wear
resistance, and strength
• Economy. Since the quality depends mainly on the water to cement ratio, the
water requirement should be minimized to reduce the cement requirement
(and thus reduce the cost).

TYPES OF CONCRETE:
• Plain/ordinary concrete
• Light Weight concrete
• High density concrete
• Reinforced Concrete
• Precast concrete
• Self compacting concrete