effects of fly ash

1. A PROJECT ON
EFFECTS OF FLY ASH ON PROPERTIES OF
M20 GRADE CONCRETE
GROUP:
B.RAJASEKHAR - 14T81A0131
G.MADHURI REDDY – 14T81A0120
B.ABHINAY – 14T81A0101
P.BHAVANI – 15T85A0101
UNDER GUIDANCE
P.ANUSHA

2. INTRODUCTION
In India now a days, the concept of smart city is
growing very faster.
Infra structure is the basic arm and smart material is
essential to achieve it properly.
Smart material is a one which gives better results in
low economy.
Considering fly ash as a smart material, it is a waste
material obtained from combustion of coal in electric
power generating thermal plants.
 Using this smart material in construction of concrete
to improve the properties.

3. The use of fly ash lowers the emission of greenhouse
gases into the atmosphere from concrete industry.
By replacing the cement with fly ash accordingly in
the range of 0%, 10%, 20%, 30%, 40% by weight of
cement in M20 grade of concrete.

4. CEMENT
Cement is a fine mineral powder manufactured with
very precise processes. It is a binder, which is used in
construction, that sets, hardens and adheres to other
materials, binding them together.

5. Cement is made by grinding together a mixture
of limestone and clay, which is then heated at a
temperature of 1,450°C which results clinker. A
combination of calcium, silicate, alumina and iron
oxide results cement.
It is the main component of concrete. It's an
economical, high-quality construction material used in
construction projects at worldwide.
Cement is a material which is sieved by using
90microns sieve.

6. INGREDIENTS OF CEMENT:
There are eight major ingredient of cement. The
general percentage of these ingredients in cement is
given below:

7. Ingredient Percentage in cement
Lime 60-65
Silica 17-25
Alumina 3-8
Magnesia 1-3
Iron oxide 0.5-6
Calcium
Sulfate
0.1-0.5
Sulphur
Trioxide
1-3
Alkaline 0-1

8. DIFFERENT TYPES OF GRADES
Mainly Different grades of cement are specified by IS
1489-1991.
 Cements are mainly classified on the basis of
compressive strength of particular cement.
Mainly 3 grades of cements are used. They are:
 GRADE 33
GRADE 43
 GRADE 53
GRADE 33 :
Fineness of grade 33 is 300m2/kg.
Grade 33 cement has high workability.
It is mainly used for mortar in masonry work and for
plastering.

9. GRADE 43 :
Fineness of grade 43 is 225 m2/kg.
Grade 43 has good workability.
It has low chloride content and thus resists corrosion on
R.C.C and it has smooth and better finish.
It is mainly used in precast concrete and reinforced cement
concrete works.
GRADE 53 :
Fineness of grade 53 is 225 m2/kg.
Volume of cement required is less due to high strength and
surface area which saves the cost of construction.
It is mainly used in industrial buildings, roads and
subways.

10. AGGREGATE
DEFINATION OF AGGREGATE
“Aggregate is a granular material, such as sand,
gravel, crushed stone,crushed hydraulic, cement
concrete, used with a hydraulic cementing medium to
produce either concrete or mortar.”
According to size, the aggregates are classified as:
• Fine aggregate
• Coarse aggregate

11. FINE AGGREGATE:
It is the aggregate most of which passes 4.75 mm IS is
termed as fine aggregate.
According to source fine aggregate may be described
as:
Natural Sand
Crushed Stone Sand
Crushed Gravel sand

12. According to size the fine aggregate may be
described as coarse sand, medium sand and fine sand.
IS specifications classify the fine aggregate into four
types.
According to it’s grading as fine aggregate of grading
Zone-1 to grading Zone-4.
Here, We have used natural sand in preparing of
concrete.
We have taken sand passes through 4.75mm IS sieve
and retained on 1mm and 600microns IS sieves .

13. COARSE AGGREGATE
It is the aggregate most of which is retained on 4.75
mm IS sieve.
 According to source fine aggregate may be described
as:

14. • Uncrushed Gravel or Stone
• Crushed Gravel or Stone
• Partially Crushed Gravel or Stone.
According to size coarse aggregate is described as
graded aggregate of its nominal size i.e. 40 mm,
20 mm, 16 mm and 12.5 mm etc.
We have used gravel passed through 20mm IS
sieve and retained on 10mm IS sieve.

15. WATER:
Water is a transparent and nearly colorless chemical
substance. It is the most important and least expensive
ingredient of concrete.
The amount of water in concrete controls many fresh
and hardened properties in concrete including
workability, compressive strengths etc.,
The insufficient quantity makes the concrete is harsh
and unworkable. The excess of water causes bleeding
and segregation in concrete.

16. FLY ASH
Fly ash is a fine powder which is a byproduct from
burning pulverized coal in electric generation power
plants.
It is identified as cementicious material.
It contains large amounts of silica, alumina and small
amount of carbon.

17. The particle size ranges between 1-100microns.
The specific gravity of fly ash is 2.15.
FLY ASH APPLICATIONS:
Fly ash can be used as prime material in blocks,
paving or bricks.
One of the most important applications is PCC
pavement. PCC pavements use a large amount of
concrete and substituting fly ash provides significant
economic benefits.
Fly ash has also been used for paving roads and as
embankment and mine fills.

18. ADVANTAGES OF FLY ASH
It is highly economical.
In addition, fly ash also requires less water
than Portland cement and it is easier to use in cold
weather.
It can be used as an admixture.
It increases strength.
It improves workability.
It reduces heat of hydration.

19. DISADVANTAGES OF FLY ASH
The quality of fly ash can affect the quality and
strength of Cement concrete.
Poor quality fly ash can increase the permeability of
the concrete and cause damage to the building.
Thus , it is very much important to use only high
quality fly ash to prevent negative effects on the
structure of the building.

20. AVAILIBILITY OF FLY ASH:
The average ash content in Indian Coal used in
thermal power plants is about 35%.
The generation of 1 MW power with Indian coal
results in co-generation of nearly 1800t of fly ash.
Out of this quantity, nearly 20% is coarser bottom ash
and about 80% (1500t) is fly ash which is collected
through Electro Static Precipitators (ESPs).

21. MIX DESIGN OF CONCRETE
The process of selecting
suitable ingredients of
concrete and determining
their relative amounts with
the objective of producing
a concrete of the required,
strength, durability, and
workability as
economically as possible,
is termed the concrete mix
design.

22. According to Indian standard specifications
(IS:456-1978 and IS 1343-1980), the concrete mixes
are designated into following seven grades:
They are M10,M15,M20,M25,M30,M35,M40.
In our mix, we have used M20 grade of concrete.
The ratio of M20 grade concrete is 1:1.5:3

23. MATERIAL
S
AT 0% OF
FLY ASH
IN (KG)
AT 10%
OF FLY
ASH IN
(KG)
AT 20% OF
FLY ASH IN
(KG)
AT 30% OF
FLY ASH
IN (KG)
AT 40%
OF FLY
ASH IN
(KG)
CEMENT 9.2946 8.365 7.4352 6.505 5.598
FLYASH 0 0.9296 1.858 2.789 3.696
FINE
AGGREGAT
E
12.5963 12.5963 12.5963 12.5963 12.5963
COARSE
AGGREGAT
E
27.7013 27.7013 27.7013 27.7013 27.7013
WATER 4.4614 4.4614 4.4614 4.4614 4.4614

24. WORKABILITY
Workability is the ease with which it can be mixed,
transported and placed in position in a homogeneous
state.
It depends on water content, shape and size of
aggregates and temperature.
(a) water content: The workability of concrete
increases with increase in water content.
(b) size of aggregates: The concrete having large
size of aggregates is more workable than that
containing small size aggregates because the smaller
size of aggregates require the more quantity of water.
(c) Temperature: The workability of concrete mix
reduces at higher temperature.

25. WORKABILITY IS MEASURED BY THE
FOLLOWING TEST:
1.Slump cone test
2.compaction factor test
3.Vee-Bee test
4.Flow test
5.Kelly-Ball test
TESTS DONE ARE:
SLUMP TEST
COMPRESSION STRENGTH TEST

26. SLUMP CONE TEST
The slump test is the most simple workability test for
concrete, involves low cost and provides immediate
results.

27. PROCEDURE FOR CONCRETE SLUMP
CONE TEST
1. Clean the internal surface of the cone and apply oil.
2. Place the cone on a smooth horizontal non- porous
base plate.
3. Fill the cone with the prepared concrete mix in 3
approximately equal layers.

28. DEGREE OF
WORKABIL
ITY
SLUMP
VERY LOW 0-25mm
LOW 25-20mm
MEDIUM 50-100mm
HIGH 100-175mm
VERY HIGH COLLAPSE
D
% FLY
ASH
SLLUMP
VALUE
IN MM
0% 25
10% 20
20% 22
30% 21
40% 20

29. 4. Tamp each layer with 25 strokes of the rounded end
of the tamping rod in a uniform manner over the cross
section of the cone.
5. Remove the excess concrete and level the surface
with a trowel.
6. Clean away the mortar or water leaked out between
the cone and the base plate.
7. Raise the cone from the concrete immediately and
slowly in vertical direction.
8. Measure the slump as the difference between the
height of the cone and that of height point of the
specimen being tested.

30. CASTING OF CONCRETE CUBES :
 For cube test two types of
specimens either cubes of
15cm x 15cm x 15cm (or)
10cm x 10cm x 10cm depending
upon the size of aggregate are used.
For most of the works cubical
mould15cm×15cm×15cm.
This concrete is poured in the
mould and tampered properly so
as not to have any voids.
After 24 hours these moulds are
removed and test specimens are put
in water for curing.

31. CURING
Curing of concrete is defined as
the process of maintaining the
moisture and temperature
conditions of concrete for definite
period of time, so that it hardens
the concrete & gives the strength.
It plays an important role on
strength development and
durability of concrete.
It takes place immediately after
concrete placing and finishing.

32. COMPRESSION STRENGTH TEST
PROCEDURE
Remove the specimen from water after specified
curing time and wipe out excess water from the
surface.
Take the dimension of the specimen to the nearest
0.2m.
Clean the bearing surface of the testing machine.
Place the specimen in the machine in such a manner
that the load shall be applied to the opposite sides of
the cube cast
Align the specimen centrally on the base plate of the
machine.

33. Rotate the movable portion
gently by hand so that it
touches the top surface of
the specimen.
Apply the load gradually
without shock and
continuously at the rate of
140 kg/cm2/minute till the
specimen fails.
Record the maximum load
and note any unusual
features in the type of
failure.

34. RESULT:
TABLE:VARIATIONS OF COMPRESSIVE
STRENGTH BY ADDING DIFFERENT %’S OF
FLY ASH
% OF FLY
ASH
COMPRESSIVE STRENGTH
(N/mm2)
AT 7 DAYS AT 14 DAYS AT 28 DAYS
0% 11.215 15.348 21.721
10% 12.856 16.021 22.541
20% 14.102 17.492 23.961
30% 15.651 19.856 25.102
40% 14.961 18.321 24.013

35. TABLE:VARIATIONS OF COMPRESSIVE
STRENGTH BY ADDING DIFFERENT %’S
OF FLYASH
11.215
12.856
14.102
15.651 14.961
15.348 16.021
17.492
19.856
18.321
21.721 22.514
23.961
25.102
24.013
0
5
10
15
20
25
30
0% 10% 20% 30% 40%
At 28 Days
At 14 Days
At 7 Days

36. Fly ash can be declared as one of the most advantageous
waste material . using it as a construction material will
not only help in its disposal but will also add strength to
the structures.
The Workability of concrete improves with the increase
in fly ash content.
The consistency of cement increases with increase in fly
ash content, because consistency depends on fineness ,
and the fly ash molecules are finer than cement.
The compressive strength of concrete will go on
increasing up to 30% of fly ash replacement if we use
more than 30%,it leads to reduction in compressive
strength of concrete.
CONCLUSION

37. ANY QUERIES

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