Fly ash is a byproduct of coal combustion that can be used as a supplementary cementitious material in concrete. There are two main classes of fly ash - Class F contains a greater combination of silica, alumina and iron, while Class C has a higher lime content. Fly ash particles fill voids in concrete, improving workability and reducing water requirements. While fly ash concrete has slightly lower early strength, it achieves higher ultimate strength and is more durable due to reduced permeability and alkali-silica reactivity. Using fly ash in concrete provides benefits like reduced heat of hydration, improved pumpability, and environmentally friendly use of an industrial byproduct.

1. S U B M I T T E D T O : - S U B M I T T E D B Y : -
M R . P A N K A J D H E E M L A B R A J E S H K R . M E E N A
H O D , C I V I L D E P T . P I E T / C I V / 1 2 / 0 3 0
CONCRETE DESIGN WITH
FLY ASH

2. INTRODUCTION
 Fly ash is generated in combustion of coal in fine grey
powder .Its size is spherical .Fly ash has pozzolonic properties, as a product
from industrial plants using pulverized coal or lignite as fuel.That it react with
lime from cementitious compound. It is known as supplementry cementition
material.
 It is used pozzolan siliceous or aluminosiliceous in nature in divided form.
 It is one of the residues generated in combustion of coal.
 Comprises of fine particles which rise with the flue gases

3. Classification
It is divided in two classes :
1.Class F
2.Class C

4. Class F
Class F is fly ash produced from burning anthracite or
bituminous coal.
lime contain is less than 20%.
contains a greater combination of silica, alumina and
iron (greater than 70 percent) than Class C fly ash.

5. Class C
 Class C is produced from the burning of sub-
bituminous coal and lignite.
 Class C fly ash comes from coals which may produce
an ash with higher lime content more than 20%.
Elevated CaO may give Class C unique self-
hardening characteristics

6. FLY ASH IN CONCRETE:
 Fly ash could be an expensive replacement for Portland cement in concrete
Fly Ash particles provide a greater
workability of the powder portion of the
concrete mixture which results in greater
workability of the concrete and a lowering of
water requirement for the same concrete
consistency.

7. Properties of Fly Ash
 Chemical
 Physical

8. CHEMICAL
MATERIALS PORTLAND
CEMENT%
FLY ASH%
SiO2 21.82 53.39
Al2O3 6.49 16.07
Fe2O3 1.93 13.05
CaO 60.74 6.33
MgO 1.08 5.48
SO3 2.62 1.06
Na2O 0.14 1.59
Free Cao 0.84 0.11
1. fly ash are glassy due to
rapid cooling; cement are
crystalline & formed by
slower cooling.
2. Portland cement is rich in
lime (CaO) while fly ash is
low. Fly ash is high in
reactive silicates while
Portland cement has
smaller amounts

9.  The color varies from light to
dark grey depending upon its
carbon contents.
 fly ash particles are small, they
effectively fill voids
PHYSICAL

10. COMPARISON BETWEEN CLASSES OF FLY
ASH

11. HEAT OF HYDRATION:
•Fly Ash has a lower heat of hydration.
•Portland Cement produces considerable heat on hydration.
•In mass concrete placements the excess internal heat may contribute to
cracking.
•The use of Fly Ash may greatly reduce this heat build up and reduce
external cracking.

12. COMPRESSIVE STRENGTH:
 Typically, concrete made with fly ash will be slightly lower in
strength than straight cement concrete up to 28 days, equal
strength at 28 days, and substantially higher strength within a
year’s time.
 Thus, fly ash concrete achieves significantly higher ultimate
strength than can be achieved with conventional concrete.

13. HOW FACTORIES WORK

14. Use of fly ash stabilization
 It is the process by which we can change the
properties or design purpose
Stabilization is done by many method
1. cement stabilization
2. fly ash stabilization
3. lime stabilization..

15. Benefit of fly ash
 Reduced Water Content
 Improved Workability
 Reduced Segregation
 Improved Pumpability
 Improved Finishing
 Low Heat of Hydration
 Lower Drying Shrinkage
 Improved Long Term Strength
 Decreased Permeability
 Increased Durability
 Improved resistance to Alkali Silica Reactivity
 Improved resistance to Sulfate Attack
 Low Chloride Ingress
 Good Carbonation Protection
 Reduced Efflorescence

16. CONCLUSION:
Fly ash thus holds a vast potential for improving the
modern day concrete when it comes to quality in the
long term. In spite of being an industrial waste, it can
improve durability and reduce heat of hydration.
The prospects of fly ash are still being underused even
today. Thus keeping in mind about environmental
concerns and its indispensability as a mineral
admixture, the values of fly ash should be effectively
garnered .

17. REFERENCES:
 Concrete technology(theory and practice) –M.S shetty
 Activation of fly ash through
Nanomodification- ACI spring convention Shiho
Kawashima, Columbia University
 Enhancing performance of high volume fly ash concrete
–ACI spring convention.
 magazine of concrete research- volume 64