CIVIL ENGG

1. Presented By- PARTH DANANI
(3rd sem, Civil Engineering)

3. Developing and maintaining world’s
infrastructure to meet the future needs of
industrialized and developing countries is necessary
to economically grow and improve the quality of life.
The quality and performance of concrete plays a key
role for most of infrastructure including
commercial, industrial, residential and military
structures, dams, power plants. Concrete is the
single largest manufactured material in the world and
accounts for more than 6 billion metric tons of
materials annually. Initial and life-cycle costs play a
major role in today’s infrastructure development.
There have been number of notable advancements
made in concrete technology in the last fifty years.

4.  What is Concrete
 History of concrete
 Composition of concrete
 What is Cement
 Function
 Portland cement
 Manufacturing of cement
 Uses
 Conclusion

5. Concrete is comprised of Portland cement, fine
aggregate, coarse
aggregate, water, pozzolans, and air. Portland
cement got its name when it was first used in the
early nineteenth century in England, because its
product resembled building stone from the isle of
Portland off the British coast. Portland cement is
made by grinding a calcareous material, such as
limestone or shell, with an argillaceous (clayish)
material such as clay, shale or blast furnace slag.
These two finely ground materials are heated in a
giant rotary furnace to the point where they begin
to fuse. The resulting product is called a clinker.
The clinker is cooled and reground to a fine
powder to form Portland cement.

7. 1824—Portland Cement Invented
Joseph Aspdin of England is credited
with the invention of modern
portland cement. He named his
cement portland, after a rock quary
that produced very strong stone.
HISTORY OF
CONCRETE

8. 1992—Tallest Concrete Building
The tallest reinforced concrete
building was built in Chicago,
Illinois. The 65-story building is
known only by its street address.

9. Concrete
Composition=
• 25-40% cement
(absolute volume of cement = 7-15% ;
water = 14-21%)
• Up to 8% air (depending on top size of
coarse aggregate)
• Thus composition of concrete= cement+ sand+
aggregates+ water+ admixtures+ air

10. Therefore:
Aggregates make
up 60-75% of total
volume of concrete.

11. What is an
AGGREGATE?

12. Aggregate: the inert filler
materials, such as sand or
stone, used in making
concrete

13. Physical Properties of Aggregates:
1.Unit Weight and Voids
2. Specific Gravity
3. Particle Shape and Surface Texture
4. Shrinkage of Aggregates
5. Absorption and Surface Moisture
6. Resistance to Freezing and
Thawing

14. Although the terms ―cement‖ and ―concrete‖ are
often used interchangeably, cement is actually
an ingredient of concrete. Cements are binding
agents in concretes and mortars. Concrete is an
artificial rock-like material, basically a mixture
of coarse aggregate (gravel or crushed stone),
fine aggregate (sand), cement, air, and water.
The term portland cement is a general term
used to
describe a variety of cements used today.
Portland cements are hydraulic cements, which
means
they will set and harden by reacting chemically
with water through hydration.

15.  Material with adhesive and cohesive
properties
 Any material that binds or unites -
essentially like glue

16. Definition: “Cement is a crystalline compound of
calcium silicates and other calcium compounds
having hydraulic properties” (Macfadyen, 2006).

17.  to bind the sand and coarse aggregate
together
 to fill voids in between sand and coarse
aggregate particle
 to form a compact mass

18.  Chemical composition of Portland Cement:
a) Tricalcium Silicate (50%)
b) Dicalcium Silicate (25%)
c) Tricalcium Aluminate (10%)
d) Tetracalcium Aluminoferrite (10%)
e) Gypsum (5%)

19. Clinker compounds in Type I portland cement

20.  Hardens rapidly and largely responsible for
initial set & early strength
 The increase in percentage of this compound
will cause the early strength of Portland
Cement to be higher.
 A bigger percentage of this compound will
produces higher heat of hydration and
accounts for faster gain in strength.

21.  Hardens slowly
 It effects on strength increases occurs at
ages
beyond one week .
 Responsible for long term strength

22.  Contributes to strength development in the
first few days because it is the first compound
to hydrate .
 It turns out higher heat of hydration and
contributes to faster gain in strength.
 But it results in poor sulfate resitance and
increases the volumetric shrinkage upon
drying.

23.  Assist in the manufacture of Portland Cement
by allowing lower clinkering temperature.
 Also act as a filler
 Contributes very little strength of concrete
eventhough it hydrates very rapidly.
 Also responsible for grey colour of Ordinary
Portland Cement

24.  The 3 primary constituents of the raw
materials used in the manufacture of
Portland Cement are:
a) Lime
b) Silica
c) Alumina
 Lime is derived from limestone or chalk
 Silica & Alumina from clay, shale or bauxite

25.  There are 2 chief aspects of the
manufacturing process:
First
To produce a finely divided mixture of raw
materials – chalk / limestone and clay /
shale
Second
To heat this mixture to produce chemical
composition
 There 2 main process that can be used in
manufacturing of Portland Cement that is
i) wet process ii) dry process

26.  Raw materials are homogenized by crushing,
grinding and blending so that
approximately
80% of the raw material pass a No.200
sieve.
 The mix will be turned into form of slurry by
adding 30 - 40% of water.
 It is then heated to about 2750ºF (1510ºC)
in
horizontal revolving kilns (76-153m length
and 3.6-4.8m in diameter.

27.  Natural gas, petroluem or coal are used for
burning. High fuel requirement may make it
uneconomical compared to dry process.

28.  Raw materials are homogenized by crushing,
grinding and blending so that approximately
80% of the raw material pass a No.200 sieve.
 Mixture is fed into kiln & burned in a dry
state
 This process provides considerable savings in
fuel consumption and water usage but the
process is dustier compared to wet process
that is more efficient than grinding.

29.  In the kiln, water from the raw material is
driven off and limestone is decomposed
into
lime and Carbon Dioxide.
limestone lime + Carbon Dioxide
 In the burning zone, portion of the kiln, silica
and alumina from the clay undergo a solid
state chemical reaction with lime to produce
calcium aluminate.
silica & alumina + lime calcium aluminate

30.  The rotation and shape of kiln allow the
blend to flow down the kiln, submitting it
to
gradually increasing temperature.
 As the material moves through hotter
regions
in the kiln, calcium silicates are formed
 These products, that are black or greenish
black in color are in the form of small
pellets, called cement clinkers
 Cement clinkers are hard, irregular and ball
shaped particles about 18mm in diameter.

31. Uses
Main use is in the fabrication of concrete and mortars
Modern uses
Building (floors, beams, columns, roofing, piles, bricks, mortar, panels, plaster)
Transport (roads, pathways, crossings, bridges, viaducts, tunnels, parking, etc.)
Water (pipes, drains, canals, dams, tanks, pools, etc.)
Civil (piers, docks, retaining walls, silos, warehousing, poles, pylons, fencing)
Agriculture (buildings, processing, housing, irrigation)
USES

32. Significant advances have been made in
concrete technology during the last fifty years. This
paper has highlighted some of the significant
advancements in technologies and their effect on
the design and preservation of infrastructure. While
it is not the definitive state-of-practice for design
and preservation, it does bring to the forefront
some of the technologies that are being considered
by professionals. As with all new technologies, long
term performance monitoring identifying both
successes and failures, will prove to be invaluable
for advancing the concept of long-life pavements.
Some of the successful examples are discussed in
this paper. Many of the innovations have been
incorporated in the routine practice.