Concrete is a composite material made by mixing cement, water, and aggregates such as sand and gravel. The cement and water form a paste that binds the aggregates together. Concrete is very versatile and can be molded into any shape. It is one of the most widely used construction materials in the world due to its strength, durability, fire resistance and affordability. Proper curing of concrete by keeping it wet is important for it to gain full strength.

1. CONCRETE

2. Concrete
 Construction material
 Mixture of Portland cement, water, aggregates,
and in some cases, admixtures.
 The cement and water form a paste that hardens
and bonds the aggregates together.
 Concrete is one of the most commonly used building
materials.
 Concrete is a composite material made from several
readily available constituents
(aggregates, sand, cement/lime, water).
 Concrete is a versatile material that can easily be
mixed to meet a variety of special needs and formed
to virtually any shape.

3. Concrete
 Can be placed or molded into virtually any
shape and reproduce any surface texture.
The most widely used construction
material in the world.
The ready-mix concrete producer has
made concrete an appropriate construction
material for many applications.

4. Basic ingredients of concrete
 Binding materials: lime, cement.
 Fine aggregates: sand, surkhi etc
 Coarse aggregates: crushed stones, broken
bricks, gravel and so on.

5. Advantages
Economical
Durable
Fire resistant
Energy efficient
On-site fabrication

6.  Characteristics/Qualities of Concrete
 Concrete’s properties make it the
building material of choice for most
purposes. The most important features
are:
 Strength and Durability
 Versatility
 Low maintenance
 Affordability
 Fire-resistance
 Thermal mass
 Locally produced and used
 Compactness

7. Strength and Durability
 Used in the majority of
buildings, bridges, tunnels and dams for its
strength
 Not weakened by moisture or mould
 Concrete structures can withstand natural
disasters such as earthquakes and hurricanes
Roman buildings over 1,500 years old such as the
Coliseum are living examples of the strength
and durability of concrete

8. Versatility (usefulness)
 Concrete is used in
buildings, bridges, dams, tunnels, sewerage
systems pavements, runways and even roads
 Low maintenance
 Concrete, being , compact and non-
porous, does not attract mould or lose its key
properties over time

9. Affordability
 Compared to other comparable building
materials, concrete is less costly to produce
and remains extremely affordable
 Fire-resistance
Being naturally fire-resistant concrete
forms a highly effective barrier to fire spread

10. Thermal mass
 Concrete walls and floors slow the passage of
heat moving through, reducing temperature
swings
 This reduces energy needs from heating or
air-conditioning.

11. Locally produced and used
 Very little cement and concrete is traded and
transported internationally
 This saves significantly on transport.

12. Compactness(Density)
 Concrete must be sufficiently dense
 Compacted
 Minimum shrinkage
 Economical for desired strength
 Sophisticated appearance

13. Cement
Water
Fine Agg.
Coarse Agg.
admixtures
Main Ingredients of concrete

14. AGGREGATES
 Aggregates occupy 60 to 80
percent of the
volume of concrete.
 Sand, gravel and crushed stone
are the
primary aggregates used.
 All aggregates must be
essentially free
of silt and/or organic matter.

15. PROPERTIES OF FRESH
CONCRETE
Workability
Consistency
Bleeding
Setting Time
Uniformity

16. WATER
 Good water is essential for quality concrete.
 should be good enough to drink--free
of trash, organic matter and excessive
chemicals and/or minerals.
 The strength and other properties of
concrete are highly dependent on the
amount of water and the water-cement ratio.

17. TYPES OF CONCRETE AND ITS USES
CLASSIFICATION ACCORDING TO BINDING
MATERIAL:
concrete is classified into two major types.
(1) Cement concrete (2) lime concrete.
1-CEMENT CONCRETE
The concrete consisting of cement, sand/fine
aggregate and coarse aggregates mixed in a
suitable proportions in addition to water is
called cement concrete. In this type of concrete
cement is used as a binding material, sand as fine
aggregates and gravel, crushed stones as coarse
aggregates.

18. USES
cement concrete is commonly used in
buildings and other important architectural as
well as engineering works where strength
and durability is of prime importance

19. 2-LIME CONCRETE
The concrete consisting of lime, fine
aggregates, and coarse aggregates mixed
in a suitable proportions with water is
called lime concrete.
In this type of concrete hydraulic lime is
generally used as a binding material, sand
and cinder are used as fine aggregates and
broken bricks, gravel can be used as coarse
aggregates.

20. PLACING OF LIME CONCRETE :
Placing of concrete shall be completed within
three hours of adding water in case of
concrete is prepared with hydraulic lime.
lime Concrete should be well cured for a
period of at least 10 days.
USES:
Lime concrete is generally used for the sake
of economy in foundation works, under
floors, over roof and where cement is not
cheaply and easily available in required
quantity.

21. TYPES OF CONCRETE AND ITS
USES
CLASSIFICATION ACCORDING TO
DESIGN OF CONCRETE
(1)Plain cement concrete.
(2) Reinforced cement concrete(RCC).
(3) Pre-stressed cement concrete(PCC).

22. PLAIN CEMENT CONCRETE
The cement concrete in which no reinforcement
is provided is called plain cement concrete or
mass cement concrete.
This type of concrete is strong in taking
compressive stresses but weak in taking tensile
stresses.
USES:
Plain cement concrete is commonly used in for
foundation work and flooring of buildings.

23. REINFORCED CEMENT
CONCRETE(RCC)
The cement concrete in which reinforcement
is embedded for taking tensile stress is called
reinforced cement concrete.
In this type of concrete the steel reinforcement is
to be used generally in the form of round
bars,6mm to 32mm dia. This concrete is equally
strong in taking tensile, compressive and shear
stresses.
USES: RCC is commonly used for construction
of slabs, beams, columns, foundation, precast
concrete.

24. REINFORCED CEMENT CONCRETE(RCC)

25. CURING OF CONCRETE
 The process of keeping concrete wet to
enable it to attain full strength is known as
curing.
 The objective of curing is to prevent loss
of moisture from concrete due to
evaporation or because of any other
reasons.
 Curing should be done for a period of
three weeks but not less then 10 days.

26. CURING OF CONCRETE
 To do curing, any one of the following
method can be used.
i. The surface of concrete is coated with a
layer of bitumen or similar other
waterproofing compound which gets into the
pores of concrete and prevent loss of water
from concrete.
ii. Concrete surface is covered with waterproof
paper or with a layer of wet sand. It could
also be covered with gunny bags.

27. CURING OF CONCRETE

32. Mixing machine