AN EXPERIMENTAL ON USE OF FLY ASH PELLETS IN CONCRETE IN PLACE OF

International Journal of Research and Innovation (IJRI) 

1401-1402 


AN EXPERIMENTAL ON USE OF FLY ASH PELLETS IN CONCRETE IN PLACE OF 

GRANITE AGGREGATE 

P. Narasimha Reddy 1 , B.V.Kavyateja 2 , G.Gautham Kishore Reddy 3 

1 Research Scholar, Department of Civil Engineering, Sri Venkateswara College of Engineering & Technology, Chittoor,India. 

2 Assistant professor , Department of Civil Engineering, Sri Venkateswara College of Engineering & Technology, Chittoor,India. 

3 Assistant professor , Department of Civil Engineering, Sri Venkateswara College of Engineering & Technology, Chittoor,India. 

Abstract 

A construction industry plays vital role in India which leads into the economic developments. The materials like fine 

aggregate, coarse aggregate are used to prepare cement concrete which are easily available natural resources in our 

country, but now there is high demand in materials which have gone to a high scenario. 

The quantity of fly ash produced from thermal power plants in India is approximately 80 million tons each year, and its 

percentage utilization is less than 10%. Majority of fly ash produced is of Class F type. During the last few years, some 

cement companies have started using fly ash in manufacturing cement, known as ‘Pozzalanic Portland cement. It mainly 

concentrated on replacement of cement with fly ash but production of artificial aggregate with fly ash helps in utilizing 

large volume of fly ash in concrete. The world is much interested in this part recently due to this large scale utilization 

which also reduces environmental pollution and dwindling of natural resources. 

In this present investigation an attempt is made by partial replacing of coarse aggregate with fly ash pellets. For preparing 

fly ash pellets a ratio of 15:85 (cement: fly ash) is considered throughout investigation. The main objectives of the 

present work is focused on preparing light weight aggregates and to find optimum replacement of fly ash pellets and to 

identify the chemical compounds formed in different replacements (of fly ash pellets in coarse aggregate) by assessing 

the spatial variations in the chemical compositions which was done by using XRD studies. 

Based on the above mix ratio, fly ash aggregate are prepared and same aggregates were used for casting the cement 

concrete cubes, cylinders and same were tested for compressive strength at 3,7,28,60 and 90 days curing period and 

compared with Controlled concrete. Split tensile strength, Acid attack test also done and compared with the Controlled 

concrete. 

. The results revealed that the compressive strength properties of concrete is increased significantly up to 20% replacement 

of fly ash aggregate and later on strength decreased for 30%, 40% replacements of fly ash aggregate. 

*Corresponding Author: 

P. Narasimha Reddy , 

Research Scholar, Department of Civil Engineering, 

Sri Venkateswara College of Engineering & Technology, 

Chittoor India. 

Published: February 27, 2016 

Review Type: peer reviewed 

Volume: III, Issue : I 

Citation: P. Narasimha Reddy , Research Scholar (2016) 

"AN EXPERIMENTAL ON USE OF FLY ASH PELLETS IN 

CONCRETE IN PLACE OF GRANITE AGGREGATE" 

INTRODUCTION 

GENERAL 

Generally, now a day’s solid waste is the major problem 

in any countries. Solid wastes are materials and masses 

dumped outside by various human activities. These are 

the some of the examples of solid waste materials industrial 

waste, medical waste and domestic waste. In particular 

construction waste is the output results of removal 

of external structure, rehabilitation, destruction, construction 

and installations. This waste consists of stone, 

sand, gravel, tiles, ceramic, glass, marbles, wood, plastic, 

paper, plumbing pipes and other materials. In that 

stones, gravel and sand waste is more when compared to 

the other material. 

There are more than 70% thermal power plants in our 

country and to cope with the increasing demand of electricity, 

more thermal power plants may be set up in near 

future. It is expected that by the turn of century, the 

quantity of fly ash available will touch the figure of 1000 

million kN per annum. The disposal of such large quantities 

of fly ash is certainly a gigantic problem and a matter 

of national concern. At present, the fly-ash is disposed off 

in the following two ways. They are 

• Dry system 

• Wet system 

Dry System 

In this system, the fly ash is in dry form is carried away 

pneumatically into an overhead silo or a bunker at the 

plant. This dry fly-ash is removal by mechanical means 

such as screw feeders could be recommended only when 

the quantity of fly-ash to be handled is small. 

Wet System 

In wet system, the fly-ash is mixed with water and sluiced 

to the settling ponds or dumping areas near to the plant. 

This method is widely adopted because it is cheaper than 

234


any other method of fly ash disposal. It is however necessary 

to have the following three conditions fulfilled for 

satisfactory operation by this system: 

• Availability of large areas of waste land for ponding; 

• Regular emptying of filled up ponds and 

• Unrestricted water supply. 

PROBLEM STATEMENT 

Many studies done on fly ash aggregates fully replacement 

of coarse aggregate in concrete. By the replacement 

of fly ash aggregate saving our natural resources and less 

labour is used by not shipping raw material from distant 

places to where glass is available saving time and money. 

First we can prepare fly ash aggregate 15:85 ratio of cement 

fly ash at 0.3 water cement ratio. By the replacement 

of this fly ash aggregate, and a basic experimental 

study on the physical and mechanical properties of concrete 

containing fly ash aggregate was carried out. 

THESIS LAYOUT 

Chapter 2 includes general literature over view for studying 

the use of fly ash aggregate in engineering properties. 

This research highlighted the different properties of fly 

ash aggregate and behavior of concrete at different percentages 

of fly ash aggregate replacement in to that. 

Chapter 3 discusses scope and objective of the present 

project 

Chapter 4 displays the descriptive variables in the experimental 

testing considering the properties of aggregates 

and raw materials. This chapter states with different raw 

components of concrete, sieve analysis, concrete mix, the 

test results of concrete and compressive strength of hardened 

concrete. This chapter ends with a detailed list of the 

different proportions of fly ash aggregate used in concrete. 

SCOPE AND OBJECTIVES 

This research is mainly focusing on studying the effect of 

fly ash aggregate on the properties of concrete mixtures 

as a partially replacement of coarse aggregate. 

Within the scope of this study, the main goal is to improve 

compressive strength of concrete at what percentage of 

replacement of fly ash aggregate. Fly ash is the cheapest 

material of all concrete constituents and is much less 

expensive than natural aggregate and sand as possible to 

save money. 

The main aim of the research is to study the effect of concrete 

when partially replacing the fly ash aggregate in to 

the concrete. This objective can be achieved through the 

following conditions: 

• To determine normal consistency, initial and final setting 

times, soundness and fineness of cement. 

• To study specific gravity, water absorption of coarse aggregate 

of normal and fly ash aggregate. 

• To find out specific gravity, water absorption of fine aggregate 

of river sand and fly aggregate. 

• To examine the effects of these substances with different 

dosages like 10%, 20%, 30% and 40% replacement of 

coarse aggregate by weight in the concrete cubes on short 

term and long term strength development by finding the 

compressive strength values at different ages i.e. 3 days, 

7 days, 28 days, 60 days and 90 days. 

• To assess split tensile strength of conventional concrete 

and partially replacement of fly ash aggregate. 

• To find the strength of cement concrete cubes after conducting 

various durability test like Acid Test 

• To identify the chemical compounds formed in different 

combinations of cement concrete by assessing the spatial 

variations in the chemical compositions which was done 

by using X-Ray diffraction studies. 

RESEARCH METHODOLOGY 

The following are to be carried out in order to achieve the 

research objectives. 

•To collect the fly ash from thermal power plant RTPP. 

•Prepare the fly ash aggregate at 15:85 proportions. 

•To study about the fly ash aggregate. 

•Experimental study on strength replacement of fly ash 

aggregate in concrete. 

•Analyse the experimental results to draw conclusions. 

MATERIALS AND METHODS 

GENERAL 

The physic-chemical properties of cement, sand , granite 

aggregate and water used in the investigation were analyzed 

based on and the standard experimental procedure 

laid down in the standard codes, like IS, ASTM and BS 

codes. These standard experimental procedures were 

adopted for the determination of normal consistency, 

initial and final setting times, soundness of cement and 

compressive strength and split tensile strength. 

MATERIALS 

The materials used in the present experimental investigation 

include; 

1. Cement : Ordinary Portland cement (OPC) 

2. Mineral admixtures : Fly ash 

3. Fine aggregate : Sand 

4. Coarse aggregate 

a) Granite 

b) Fly ash aggregate 

5. Water 

Chemical characteristics of fly ash 

S. No chemical 

characteristics 

1. Silica + alumina+ 

iron 

oxide % by 

mass 

2. Silicon 

dioxide % by 

mass 

3. Magnesium 

oxide % by 

mass 

4. Sulphur 

trioxide % by 

mass 

5. Available 

alkalies as 

sodium oxide 

% by mass 

6. Loss on ignition 

Requirement Composition 

of fly ash 

used 

70 (min) 94.2 

35 (min) 53.0 

5 (max) 1.19 

2.75 (max) 0.04 

1.5 (max) 0.46 

12 (max) 0.34 

235


Benefits 

• Reduces bleeding, 

• Increase time of setting, 

• Improve workability, 

• Reduces segregation in plastic concrete, 

• Increases ultimate strength, 

• Reduces drying shrinkage and permeability, 

• Lowers the heat of hydration 

Fine aggregate 

The sand used throughout the experimental work ws obtained 

from Chittoor, Chittoor district, Andhra Pradesh. 

Sand was thoroughly washed with tap water to remove 

impurities like decayed vegetable matter, humus, organic 

matter and deleterious materials like clay, fine silt and 

fine dust and was oven dried for 24 hours and cooled to 

room temperature and hence care was taken for the sand 

used in the investigation. 

In the present work the size of the sand is passing through 

4.75 and retaining on 150mm as per IS sieve. The specific 

gravity of sand is 2.6. sand is tested for specific gravity, in 

accordance with IS: 2386-1963(Part I and II) 

Sand Properties 

S.NO Properties Sand values 

1 Specific gravity 2.6 

2 Water absorption 1.0 

(%) 

3 Bulk density (Kg/ 1.460 

m3) 

4 Fineness modulus 

(%) 

3.12 

Compressive strength 

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. 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 140kg/ 

cm2/minute till the specimen fails. Record the maximum 

load and note any unusual features in the type of failure. 

Samples Testing 

Concrete cube specimens 

In carrying out the X-ray diffraction, the concrete samples 

are first grinded into powder form. The sample size 

is normally 0.002mm to 0.005 mm and then they are put 

into the small packets. X-ray diffraction (XRD) data for 

grind samples were tested on Panalytical’s X’Pert Pro with 

Cu Kα radiation at IIT Ropar, Punjab. The samples are 

scanned in the range of 2Ѳ = 5 - 60˚ at the scanning speed 

of 2˚/min. 

X-ray powder diffraction (XRD) is a rapid analytical technique 

primarily used for phase identification of a crystalline 

material and can provide information on unit cell 

dimensions. The analyzed material is finely ground, homogenized, 

and average bulk composition is determined 

4.4.3.1 Fundamental Principles of X-ray Powder Diffraction 

(XRD) 

Max von Laue, in 1912, discovered that crystalline substances 

act as three-dimensional diffraction gratings for 

X-ray wavelengths similar to the spacing of planes in a 

crystal lattice. X-ray diffraction is now a common technique 

for the study of crystal structures and atomic spacing. 

X-ray diffraction is based on constructive interference of 

monochromatic X-rays and a crystalline sample. These 

X-rays are generated by a cathode ray tube, filtered to 

produce monochromatic radiation, collimated to concentrate, 

and directed toward the sample. The interaction of 

the incident rays with the sample produces constructive 

interference (and a diffracted ray) when conditions satisfy 

Bragg's Law (nλ=2d sin θ). This law relates the wavelength 

of electromagnetic radiation to the diffraction angle 

and the lattice spacing in a crystalline sample. These diffracted 

X-rays are then detected, processed and counted. 

By scanning the sample through a range of 2θangles, all 

possible diffraction directions of the lattice should be attained 

due to the random orientation of the powdered material. 

Conversion of the diffraction peaks to d-spacings 

allows identification of the mineral because each mineral 

has a set of unique d-spacings. Typically, this is achieved 

by comparison of d-spacings with standard reference patterns. 

All diffraction methods are based on generation of X-Rays 

in an X-ray tube. These X-rays are directed at the sample, 

and the diffracted rays are collected. A key component of 

all diffraction is the angle between the incident and diffracted 

rays. Powder and single crystal diffraction vary in 

instrumentation beyond this. 

236


X-ray Powder Diffraction (XRD) Instrumentation 

X-ray diffractometers consist of three basic elements: an 

X-ray tube, a sample holder, and an X-ray detector 

RESULTS AND DISCUSSIONS 

Comparison between Compressive Strength for 0 and 20% replacement 

of Fly Ash Aggregate 

GENERAL 

In this chapter the parameters studied on the control 

concrete and fly ash aggregate replaced concrete are discussed. 

The parameter such as compressive strength was 

discussed and comparison between the control concrete 

and fly ash aggregate concrete is represented. 

Concrete is the most widely used manufactured material 

in the construction industry. It’s the most important 

property is durability which relates the performance of 

the material to its service life under various environmental 

conditions. The ability of concrete to withstand and 

satisfactorily and for long periods the effects of load, time, 

and environment depends very much on how the engineering 

properties of the material are constituted initially 

and how they are allowed to develop with age. 

The use of cementitious and pozzolanic siliceous industrial 

by-products as mineral admixtures-in concrete can 

bring improvements in engineering properties of concrete 

(strength, impermeability and general durability). Normal 

pozzolan additives due to their low surface area and reactivity 

are not generally able to improve the early strength 

which is crucial to the strength and stability of structural 

concrete applications and durability of concrete. The 

problem, though, could be solved by using a mixture of 

normal (such as fly ash, silica fume and slag) and a highly 

reactive pozzolan, to produce a durable concrete which 

does not suffer from low early strength. 



SLUMP CONE TEST RESULTS 

Percentage change in compressive strength of concrete cubes 

made with partially replacement of fly ash pellets 

The above graph shows the variation of compressive 

strength at different percentage of fly ash aggregate. At 

10% replacement level of fly ash aggregate as coarse aggregate 

in concrete the compressive strength at 3, 7,14, 

21, 90 days is increased as compared to conventional 

concrete is 26.7%,13.6%,4.117%,2.21%,1.9% respectively. 

And at 28 and 56 days the compressive strength is 

decreased as 15% and12.5% respectively. 



237


SPLIT TENSILE TEST 

The test was carried out conforming to IS 5816-1999 to 

obtain Split tensile strength of concrete at the age of 28 

days. The cylinders were tested using Compression Testing 

Machine (CTM) of capacity 2000KN. Then it is tested 

for different percentage fly ash aggregate replaced as sand 

in concrete.Table 5.5 Split Tensile Strength Values. 

S. No Fly ash percentage 

(%) 

1 0 2.2 

2 10 2.264 

3 20 2.123 

4 30 2.112 

5 40 2.045 

Split Tensile 

Strength for 28 

days 

• By increasing the replacement of fly ash aggregate in 

concrete the compressive strength will be decreasing 

gradually. 

• At 20% replacement level of fly ash aggregate used as 

coarse aggregate in concrete the compressive strength is 

increased as compared to conventional concrete and further 

it goes to decreasing. 

• In developing countries like India it is difficult to dispose 

this waste because it causes different environmental 

problems. 

• So, by this project it is proved that fly ash aggregate 

used as coarse aggregate replacement at 20% in conventional 

concrete practices. 

• It can be seen that the replacement percentage of fly ash 

is between 5% to 20%, maximum strength is obtained at 

20 %. 

• Split tensile values are decreased by the replacement of 

fly ash aggregate 

• While doing the acid curing test it is observed that the 

compressive strength of concrete replaced with fly ash aggregate 

is decreased. 

• By the use of fly ash aggregate we can reduce the use 

of natural aggregate. Then the scarcity of aggregates can 

also be reduced. 

ACID ATTACK 

Split Tensile Strength for 28 days 

Weight Loss Acid Attack Values 

Fly ash 

aggregate 

(%) 

Average 

dry weight 

curing of 

the cubes 

(gm) 

Average 

dry weight 

after 56 

days curing 

Weight 

reduced 

(gm) 

Percentage 

of weight 

reduced(% 

0 8310 8125 185 0.022 

10 8200 7990 210 0.025 

20 7895 7615 280 0.354 

30 7610 7440 170 0.023 

40 7449 7350 99 0.013 

CONCLUSIONS 

The following conclusions are made based on the comparative 

analysis of conventional concrete properties of test 

results to the replacement of fly ash aggregate as coarse 

aggregate into the concrete test result values. 

At 10% replacement level of fly ash aggregate as coarse 

aggregate in concrete the compressive strength at 3, 7,14, 

21, 90 days is increased as compared to conventional 

concrete is 26.7%,13.6%,4.117%,2.21%,1.9% respectively. 

And at 28 and 56 days the compressive strength is 

decreased as 15% and12.5% respectively. 

At 20% replacement of fly ash aggregate as coarse aggregate 

in concrete the compressive strength for 3, 7, 

14, 21, 28, 56 and 90 days is increased by 38%, 23.8%, 

13%,7.46%, 5.53%, 4.85%, 3.56% respectively as compared 

to conventional concrete. 


in concrete the compressive strength is increased for 

3,7, 14 and 21 days is 28.7%, 16.5% ,8.27% and 2.1%. 

And 28, 56, and90 days strength is decreased by 17.5%, 

16.84% and 20.3% respectively as compared to conventional 

concrete. 


in concrete the compressive strength for 3,7 and 14 

days is increased by 21.7%, 11.58% and 1.76% respectively 

and at 21, 28, 56 and90 days strength is decreased 

by 4%, 22.7%, 21.56% and 24% respectively as compared 

to conventional concrete. 

• With increasing of fly ash aggregate as coarse aggregate 

into the concrete then the workability is decreased gradually 

as compared to the conventional concrete. 

• By using fly ash aggregate particles into the concrete the 

water absorption quantity should be increases gradually 

with increasing of fly ash aggregate. 

• Compressive strength of concrete is dependent on the 

use of fly ash aggregate product. 

238


REFERENCES 

AUTHOR 

1. A.Camoes (2004): “Durability of High Volume Fly ash 

concrete”. 

2. A.M.Nevile, “Properties of concrete” , ELBS with Longman 

1987 

3. An Experimental Study on PartialReplacement of Natural 

Coarse Aggregate With Fly Ash Coarse Aggregate 

(FACA), Vol. 2 Issue VI, June 2014 ISSN: 2321-9653. 

4. Bouzouboa et al (2004): “At Canmet Canada have done 

studies on the mechanical properties of concrete made 

with blended high volume fly ash cements”. 

P. Narasimha Reddy 

Research Scholar, 

Department of Civil Engineering, 


Chittoor,India. 

5. Dr. Sravana1 Sarika.P, Dr.SrinivasaRao, Dr.Seshadri 

Sekhar T &Apparao.G:“Studies on Relationship between 

Water/Binder Ratio and Compressive Strength of High 

Volume Fly Ash Concrete”. 

6. Faseyemi V.A (2012): “Investigation on Fly Ash as a 

Partial Replacement in Concrete”. 

7. IS 456-2000 -Code of practice for plain & reinforced 

cement concrete. 

8. IS 12269-1987-Specification for OPC 53 grade. 

B.V.Kavyateja 

Assistant professor , 




9. IS 10262-1982-Recommended guide line for concrete 

mix design. 

10. IS 3812-1981-Specifications of fly ash for use as pozzolana& 

admixtures . 

11. IS 3812(Part1)-2003-Specifications for pulverized fuel 

ash for use as cement, cement mortar and concrete (Second 

Revision). 

12. IS 9103-1999-Concrete admixture –Specifications. 

13. IS 516-1965-Method of Test for Strength of Concrete. 

G.Gautham Kishore Reddy 

Assistant professor , 




14. IS 383-1970-Specification for coarse aggregate and 

fine aggregate from natural sources. 

15. IS 650-1966-Specification for standard sand for testing 

of cement. 

16. IS 2386 (Part 3)-Method of test for aggregates for 

concrete-Specific gravity, density, voids, absorption and 

bulking 

17. K. Arunachalam& R. Gopalakrishnan(29th Conference 

on our world inconcrete & structures:25 - 26 August 

2004), “Experimental Investigation on High Performance 

Fly Ash Concrete in Normal and Aggressive Environment”. 

18. Langley et al (1990): “Reported two case histories 

where high volume fly ash concretes”. 

19. M.S. Shetty, “Concrete Technology”, Year 2008 

20. M.L.Gambhir, “Concrete Manual”, DhanpatRai Publications, 

239

AN EXPERIMENTAL ON USE OF FLY ASH PELLETS IN CONCRETE IN PLACE OF

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