Investigation of Crack Width Development in Reinforced Concrete Beams Using Fly Ash

Arumbaka Ramesh Int. Journal of Engineering Research and Applications www.ijera.com
ISSN: 2248-9622, Vol. 5, Issue 12, (Part - 2) December 2015, pp.57-70
www.ijera.com 57|P a g e
Investigation of Crack Width Development in Reinforced
Concrete Beams Using Fly Ash
Arumbaka Ramesh, E. Bala Koteswara Rao
Scholar in Chinthalapudi Engineering College With Roll No: 137r1d8701 In Structural Engineering
(Assitant Professor) In Chinthalapudi Engineering College Branch: Structural Engineering
ABSTRACT
Due to increase in thermal power plants in India lot of fly ash is produced. The disposal of fly ash causes
negative impact on the environment in the way of water pollution, air pollution and finally effect on the eco
system. Hence disposal of fly ash is challenging task for engineers.
Lot of earlier investigations reported that fly ash has some cementing properties it can be replaced as cement
upto some percentage. Hence in this investigation an attempt has been made to replace the cement by fly ash
and investigated the resulting properties.
In this project work presented Cubes and Reinforced concrete beams are tested for Compression and Flexural
Strength of Design Mix M30 by varying the cement content with Certain proportions as follows.
1) Anormal OPC mix
2) Cement replace by 20% fly ash mix
3) Cement replace by 30% fly ash mix
4) Cement replace by 40% fly ash mixes of the same water cement ratio.
(a) The tests conducted for above mixes are shown below.
1) The fresh concrete properties are workability in terms of slump cone test and compaction factor test.
2) 8mm and 10mm diameter bars are used as tension and compression reinforcement. 6mm diameter bars are
used as vertical stirrups.
3) The engineering properties such as compressive strength, flexural strength of reinforced concrete were
measured in 14 days and
4) Determining the crack width development of reinforced concrete beams with different percentage of fly
ash with different cover depths.
After the investigation it is observed that fly ash can be effectively used to replace the cement upto 40
percentage.
The use of fly ash in concrete serves the triple benefits.
 Safe disposal of fly ash
 Conservation of natural material (cement)
 Return of income
I. INTRODUCTION
Concrete is a composite construction material,
composed of cement (commonly Portland cement)
and other cementitious material like fly ash and
aggregate (generally a coarse aggregate made of
gravel or crushed rocks such as granite, plus a fine
aggregate such as sand), water.
Concrete has been most extensively used in
buildings ever since Joseph invented and patented
Portland cement, about one hundred sixty years ago.
At its face value, concrete is a simple material close
to the natural one. It is a robust and reasonably
durable one, with compressive strength going up to
150Mpa under controlled conditions in suitable
combination of the components.
The cement industry is one of two primary
producers of carbon dioxide (CO2), creating up to 5%
of worldwide man-made emissions of this gas, of
which 50% is from the chemical process and 40%
from burning fuel. The CO2 emission from the
concrete production is directly proportional to the
cement content used in the concrete mix; 900 kg of
CO2 are emitted for the production of every ton of
cement.
It is widely known that water/cement ratio
primarily governs the strength of concrete and lower
water/cement ratio gives higher strength. Another
important requirement is that the concrete should
have adequate workability at the time of casting so
that it can be properly compacted with minimum air
voids.
The inclusion of Fly ash affects all aspects of
concrete. As a part of the composite concrete mass, it
can be used both as a fine aggregate as well as a
cementitious component. It influences the rheological
properties of fresh concrete as well as the finished
RESEARCH ARTICLE OPEN ACCESS

product. It improves the strength and durability of the
hardened mass. It reduces segregation, bleeding and
lowers the heat of hydration apart from the energy
and cost saving aspects.
There are other important points one must pay
attention to, regarding reinforcement besides its
strength and bond. The durability of a structure
depends on the quality of the materials and
construction, the design specification and detailing,
the time and environmental factors. Concrete
structures are subjected to dynamic loads such as
guest wind; cyclonic weather and earthquake undergo
repeated reversal of stress. Such loads cause micro
cracking and increasing brittleness of the concrete.
Reinforcement is required for protection against
cracking of concrete and also to provide ductility to
the structure.
Industrial by products, such as fly ash, silica
fume and blast furnace slag are increasingly used
worldwide to produce dense and impermeable
concrete. In countries where these materials are
available as waste products, their use in concrete not
only enhances its durability but also decreases its
lost. It is found that high strength and high
performance concrete can be produced using such
materials. Fly ash is the material used in the
production of high strength concrete.fly ash is used as
early as in 1935 for cement replacement. In India
about 115 million tones of fly ash have been
produced by 82 major thermal power stations. It has
been a published fact from research that waste
material like fly ash through their use as construction
materials can be converted into meaningful wealth.
In generally the cracking of concrete will occur
whenever the tensile strength of concrete is exceeded
or (Fcr = 0.57*sqrt (fck)). Cracks are likely to form on
the surface in the tensile zone, midway between two
adjacent bars. There is a similarity between the
development of flexural micro cracking in reinforced
and plain concrete beams when the load deflection
curve deviates from that of a straight line. There are
limits on cracking, those are
(i) Cracking is varying with the type of structure
and its environment. The limit of crack
according to code is 0.3mm
(ii) If the cracking is in the tensile zone then the
width according to code is 0.2mm (cracking in
tensile zone is harmful).
The factors affecting the crack width are
 Tensile stress in steel bars.
 Thickness of concrete cover.
 Diameter and spacing of bars.
 Bond and tensile strength
1.2. Importance of The Study
In the era of rapid globalization and
industrialization, thermal power plants are being set
up in large numbers to meet the increasing energy
demand. Coal is the most economic and easily
available fuel for power generation in India and ever
growing future demands of energy will certainly be
making use of this source more and more. The
present known coal reserves at the present demand
rate are to last for more than 400 years and are likely
to increase as new discoveries of coal fields have
been reported and more discoveries might follow. In
India high grade coal is reserved for metallurgical
industries and the railways and the thermal power
stations have to use high ash low grade coal due to
the low calorific value(about 3500K.cals per kg) and
high ash content (30 to 50 percent),The thermal
power stations produce huge quantities of ash
generally known as fly ash.
A huge generation of this waste has become a
threat for a hygienic environment and the health of
the nearby habitats. According to a recent report,
India has about 82 thermal power stations, producing
about 115 million tones of fly ash per annum. The
production of fly ash on average is to the tune of
5tonnes/ mw/day of power generated exceeds 3lakh
tones/day. In India about 150 million tonnes per
annum of generation of fly ash is anticipated by 2010
A.D. hence it is the need of the day to dispose of such
a huge quantity of fly ash by appropriate means.
If it is disposed of by dumping on earth, then
2.47 acres of land space is required per mw of power
generated. Hence it would again prove costly against
the rising cost of land, also crores of rupees to
transport the fly ash to ash ponds need to be spent. If
it is dumped in to rivers or sea, it would create
another problem by silting of rivers and eradication
of human and aquatic lives depending upon these
sources of water. Therefore, the task for the nation
ahead is to identify the field applications where fly
ash can be utilized constructively without affecting
the human life and nature.
Construction industry is a single body which can
solve this gigantic problem. The construction
industry plays a most vital role in the socio-economic
growth of the nation, and the progress of the nation
depends upon availability of good quality materials in
sufficient quantity at a comparatively reasonable cost
for construction industry is seriously hampered with
escalating cost of primary construction materials,
especially cement, sand, coarse aggregate.
Since its discovery over 150 years ago, Portland
cement has become almost a „wonder‟ material and a
household name. the raw materials needed or its
manufacture are available in most parts of the world,
and the energy requirements for its production are
available in most parts of the world, and the energy
requirements for its production are relatively modest.
Nevertheless many countries have severe shortages
of cement, although their needs are vast. The search
for alternative binders and cement replacement
materials has thus become a challenge for national

development and forward planning in many
developed countries. On the other hand, apart from
the need to save energy, there is an urgent
requirement to project concrete as a reliable and
durable construction material.
A lot of research on the subject of fly ash
utilization has been made by scientific organizations
such as CBRI, I.I.Sc and various pollution control
research institutes. Many suggestions have been put
forth. CBRI has brought out many data sheets. BIS
has evolved various IS codes. The enormous volume
of published papers, the number of national and
international conferences and symposia that have
been held on this subject since 1980.
Since there is huge amount of fly ash left in the
disposal ponds, unless urgent steps are taken to
ensure maximum utilization of fly ash, thousands of
acres of fertile land will be lost just for dumping of
fly ash, which in turn creates many problems, such as
 The pollution level has gained unprecedented
height and this is being attributed to a prolonged
dry spell.
 Fly ash smog‟s when high wind blows, at times,
the fly ash will spread in a radius of over 10 km.
 Fly ash frequently smog‟s the surrounding
villages causing irritation in eyes and throat
problems in the residents.
 Clothes are often covered with fly ash during
high winds causing un-hygienic conditions.
 The cattle fodder is frequently affected causing
disorders.
Crops were the worst hit and several open wells
in the vicinity area also discolored and polluted.
Local medical experts warn against the spread of
chronic bronchitis. Even to install water sprinklers,
to keep the fly ash in wet condition is very expensive.
To solve the problems of effective fly ash disposal
and use in construction works, this project work was
taken up and an attempt in finding out a probable
outlet for utilization of fly ash as partial replacement
of cement in concrete at 20%, 30% and 40% by
weight of cement.
1.3 Objective of The Study
• The main objective of the present work is to
study the crack development on RC beams with
different cover depths and different proportions
of fly ash.
• The objective of this investigation is to prepare
concrete mix by replacing cement with different
proportions of fly ash up to some extent and to
prove that concrete can attain good properties
such as strength and workability.
• The cement replacement levels by fly ash are 20,
30 and 40 percent in reinforced concrete beams.
1.4 Scope of The Study
The scope of present study includes the
following aspects:
Laboratory tests on cement, fine aggregate, fly
ash and coarse aggregate.
Reference concrete mix designs for concrete of
grade M30 according to IS: 10262 –1982,
recommended guide lines for concrete mix designs.
Conducting trial mixes as per designed workability
and compressive strength of concrete. Specimens
were tested at the age of 14 days.
• Casting cubes of size 150mmx150mmx150mm,
with different percentages of fly ash for testing
compressive strength of concrete.
• Casting of beams of size
100mmx100mmx500mm with different
percentages of fly ash for testing flexural
strength of concrete.
• 8mm and 10mm dia bars are used as tension and
compression reinforcement. 6mm dia bars are
used as vertical stirrups.
• Finding crack width of beams with different
percentages of fly ash with different clear covers.
II. Fly Ash Concrete
Fly Ash
According to the American Concrete Institute
(ACI) Committee 116R, fly ash is defined as „the
finely divided residue that results from the
combustion of ground or powdered coal and that is
transported by flue gasses from the combustion zone
to the particle removal system’ (ACI Committee 232
2004). Fly ash is removed from thecombustion gases
by the dust collection system, either mechanically or
by usingelectrostatic precipitators, before they are
discharged to the atmosphere. Fly ashparticles are
typically spherical, finer than Portland cement and
lime, ranging indiameter from less than 1µ to no
more than 150 µm.
• The types and relative amounts of incombustible
matter in the coal determine the chemical
composition of fly ash. The chemical
composition is mainly composed of the oxides of
silicon (SiO2), aluminum (Al2O3), iron (Fe2O3),
and calcium (CaO), whereas magnesium,
potassium, sodium, titanium, and sulphur are
also present in a lesser amount. The major
influence on the fly ash chemical composition
comes from the type of coal. The combustion of
sub-bituminous coal contains more calcium and
less iron than fly ash from bituminous coal. The
physical and chemical characteristics depend on
the combustion methods, coal source and particle
shape.
The chemical compositions of various fly ashes
show a wide range, indicating that there is a wide
variations in the coal used in power plants all over
the world (Malhotra and Ramezanianpour 1994).

• Fly ash that results from burning sub-bituminous
coals is referred as ASTM Class C fly ash or
high-calcium fly ash, as it typically contains
more than 20 percent of CaO. On the other hand,
fly ash from the bituminous and anthracite coals
is referred as ASTM Class F fly ash or low-
calcium fly ash. It consists of mainly an alumino
silicate glass, and has less than 10 percent of
CaO. The color of fly ash can be tan to dark
grey, depending upon the chemical and mineral
constituents (Malhotra and Ramezanianpour
1994; ACAA 2003). The typical fly ash
produced from Australian power stations is light
to mid-grey in color, similar to the color of
cement powder. The majority of Australian fly
ash falls in the category of ASTM Class F low
calcium fly ash, and contains 80 to 85% of silica
and alumina (Heidrich 2002).
• A side from the chemical composition, the other
characteristics of fly ash that generally
considered is loss on ignition (LOI), fineness and
uniformity. LOI is a measurement of unburnt
carbon remaining in the ash. Fineness of fly ash
mostly depends on the operating conditions of
coal crushers and the grinding process of the coal
itself. Finer gradation generally results in a more
reactive ash and contains less carbon.
• In 2001, the annual production of fly ash in the
USA was about 68 million tons. Only 32 percent
of this was used in various applications, such as
in concrete, structural fills, waste
stabilization/solidification etc. (ACAA 2003).
Ash production in Australia in 2000 was
approximated 12 million tons, with some 5.5
million tons have been utilized (Heidrich 2002).
Worldwide, the estimated annual production of
coal ash in 1998 was more than 390 million tons.
The main contributors for this amount were
China and India. Only about 14 percent of this
fly ash was utilized, while the rest was disposed
in landfills (Malhotra 1999). By the year 2010,
the amount of fly ash produced worldwide is
estimated to be about 780 million tons annually
(Malhotra 2002). The utilization of fly ash,
especially in concrete production, has significant
environmental benefits, viz, improved concrete
durability, reduced use of energy, diminished
greenhouse gas production, reduced amount of
fly ash that must be disposed in landfills, and
saving of the other natural resources and
materials (ACAA 2003).
2.1 Review of Literature on Fly Ash Concrete
M.M.Prasadinvestigated the effect of 17%, 22%,
27% and 32% cement replacement by fly ash and
silica fume on conventional M20 grade of concrete.
M20 grade of concrete has been considered as
reference mix. Specimens are cast and cured
normally for 28 days and then tested for flexural
strength and split tensile strength to failure as per IS
specifications and the results have been compared.
The test results shows that the flexural and split
tensile strength of fly ash- silica fume concrete
containing up to 27% fly ash plus silica fume are
comparable to that of conventional concrete.
Canon has stated that by adding fly ash to the extent
of 15% by weight of cement in lean concrete
(W/C=0.8) strength equal to the corresponding plane
concrete within 90 days was achieved.
Deepa A. Sinha and Elizabeth George has designed
M25 and M30 concrete mixtures with different
percentages of fly ash substitution without any
addition of chemical admixtures. It was found that
not only the 28 and 90 days compressive strength but
also the flexural strength and durability of fly ash
concrete was satisfactory up to 50% fly ash
substitution for cement.
OsmanAhmad had done extensive work on the
utilization of fly ash in concrete with 15 cm max size
of coarse aggregate. According to him, large doses of
fly ash in lean and rich concrete could result in a
saving to about 40% and 30% respectively in cement
content over the current practices of substitution of
fly ash to the extent of 20% by weight. In all the fly
ash mixes studied, the sand content was reduced by
amount equivalent to the absolute amount of fly ash
added.
Dhuraria has recorded that earlier strengths could be
achieved in fly ash concrete by adjusting the various
ingredients in such a way that the quantity of cement
and fly ash in the final mix is more than the quantity
of cement replaced. Fly ash concrete mix appeared
drier than normal concrete mix but gets satisfactorily
compacted with adequate vibration.
D.Heinz, K. Miskiewicz and L. Urbonashas stated
that, for ecological and economical reasons the
substitution of natural raw materials by industrial by-
products is of great importance. The use of fly ash
from coal-fired power plants as an active addition in
the production of cement can improve special cement
properties and lower the CO2 –emissions associated
with the cement production.
Hognestad (1991) observed in his paper that
concrete cover is a critical important variable
governing service life of concrete structures. It
ensures the bond between concrete and reinforcement
steel required developing structural strength. It
projects reinforcement against corrosion. Increased
cover also provides resistance to mechanical
abrasion.

Love well and Washa has stated that fly ash concrete
may develop some compressive strength as the
corresponding plain concrete at earlier ages by over
dosing the fly ash suitability.
Madhur stated that large quantity of fly ash to the
extent of 150 to 200% or even more by weight of
cement could be used in lean mass concretes and the
cement content reduced by more than 20 to 30%
without sacrificing the strength at long ages.
NevilleAm has mentioned that fly ash particles are
spherical (which is advantageous from the water
requirement point) and are approximately of some
fineness as cement so that silica is readily available
for reaction. In considering pozzolanic in general,
silica has to be amorphous or crystalline. Silica has
very low reactivity; Portland pozzolanic cements gain
strength very slowly and require curing over a
comparatively longer period. Their ultimate strength
is approximately the same as that of ordinary
Portland cement. Generally pozzolonas are used
technically rather than for economic reasons.
1Prof.Indrajit Patel, 2Dr.C D Madera has stated
that the use of high volume fly ash (HVFA) concrete
opts in very well with sustainable development. High
volume fly ash concrete mixtures contain lower
quantities of cement and higher volume of fly ash (up
to 60%). Experiments were done on HVFAC
mixtures containing fly ash up to 60% by weight of
cement. The compressive strength gaining is
comparatively slower at 3 and 7 days for all mixes
particularly for high 60% of fly ash and higher mix
M35 and M40. Targeted values at 7 days for plain
HVFA concrete is of the 72% to 78% which is as
better as normal concrete without fly ash. Beyond 7
days the increase in strength is of order 65 to 76%
and all mixes shows satisfactory values at age of 28
days.
Sanjay Bahadurand Devendra Kumar Pandey has
stated that the use of fly ash and other supplementary
cementitious materials has been proven to be an
essential factor for durability of concrete and overall
sustainable development in future.
S.S.Reshi has stated that most of Indian fly ashes
posses‟ good pozzolanic activity and can be used to
replace 20% cement by weight in structural concrete
mixes. The results were based on various tests made
by C.B.R.I. A method to get 28 days equivalent
strength of concrete even with fly ash concrete was
recommended in which sand and coarse aggregate
were also proportioned in addition to the replacement
of cement by weight up to 20% with fly ash
V.M.Malhotra etal9
studied the properties of
concrete with wide range of fly ash up to 58% of the
total cementitious material. The concrete mixes were
tested for compressive strength and resistance to
chloride ion penetration at various ages up to 1 year.
He stated that HVFAC has adequate early age and
excellent later age mechanical properties and
demonstrates remarkable performance in most
durability aspects.
2.2 CANMET International Conferences
The CANMET has played a significant role in
Canada for over 30 years in research on fly ash
ferrous and non ferrous slag and silica flume, in order
to conserve both the resources and the energy and
also to reduce the emission of C02 commencing since
1983, CANMET has been conducted international
conferences at an interval of 3 years till to date, to
promote the conservation resources and energy
durability of concrete and reduction of C02 into the
atmosphere. All these are associated with concrete
technology relative to durability, ecology and
economy. Seven international conferences are held to
date by CANMET.
In July-august 1983, CANMET, in association
with American concrete institute (ACI) and U.S
corps of engineers, sponsored 5 day international
conferences at Montebello, Cuebec, Canada on the
"use of fly ash, silica flume, slag and other mineral
by products in concrete". The main purpose of these
conferences was to bring together the representatives
from industries, universities and government
agencies to present latest information on these
materials and to explore new areas of needed
research ACI SP- 79 contains all the papers of 15
countries.
The international conferences held by CANMET
at different places are in 1986, Madrid, Spain, in
1989 at Trondheim, Norway. The fourth international
conference in1992 in Istanbul, Turkey.In 1995 at
Milwaukee, U.S. in 1998 at Bangkok, Thailand.
In 2001 CANMET in association with the ACI,
electric power research institute, U.S.A and several
other organizations in Canada and India sponsored
the seventh CANMET / ACI, international
conference on fly ash silica flume, slag and natural
pozzolanic in concrete. The knowledge accumulated
because of these conferences is of immense value.
These conferences immensely developed the HVF A
concrete.
Jain and Maiti [13] pointed out the under utilization
of fly ash in India is due to lack of information n
durability on Indian fly ash. They reported studies on
the various properties of M20 concrete with HVFA.
Poon [9] presented the results of the laboratory study
on HSC with large volume of low calcium fly ash.

There experimental results show that a 28 days
compressive strength of 80Mpa could be obtained
with a water/binder ratio of 0.24, with a fly ash
content of 45%.
Pozzolanic Activity:
A pozzolanic is defined as a siliceous and
aluminous mixture which in itself possesses little or
no cementitious value but which will in finely
divided form and in presence of moisture chemically
react with calcium hydroxide at ordinary temperature
to form components possessing cementitious
properties. Pozzolanic activity is most related to the
reaction between the reactive silica and the alumina
of the pozzolanic and calcium hyroxide. Fly ash is
one such material which exhibits pozzolanic activity.
2.3 Use of Fly Ash in Concrete
One of the efforts to produce more
environmentally friendly concrete is to reduce the use
of OPC by partially replacing the amount of cement
in concrete with by-products materials such as fly
ash. As a cement replacement, fly ash plays the role
of an artificial pozzolanic, where its silicon dioxide
content reacts with the calcium hydroxide from the
cement hydration process to form the calcium silicate
hydrate (CS- H) gel. The spherical shape of fly ash
often helps to improve the workability of the fresh
concrete, while its small particle size also plays as
filler of voids in the concrete, hence to produce dense
and durable concrete.
An important achievement in the use of fly ash
in concrete is the development of high volume fly ash
(HVFA) concrete that successfully replaces the use of
OPC in concrete up to 60% and yet possesses
excellent mechanical properties with enhanced
durability performance. HVFA concrete has been
proved to be more durable and resource-efficient than
the OPC concrete (Malhotra 2002). The HVFA
technology has been put into practice, for example
the construction of roads in India, which
implemented 50% OPC replacement by the fly ash
(Desai 2004).
More than two thousand years ago Roman
builders recognized that certain volcanic ash was
capable of forming cements when combined with
lime. The Romans widely exploited this pozzolanic
property of volcanic ash and many structures from
the Roman period are still intact. The modern
recognition that fly ash is pozzolanic has led to its
use as a constituent of contemporary Portland cement
concrete.
The term fly ash was first used by the electrical
power industry in 1930. The first comprehensive data
on its usage in concrete in North America was
reported in 1937 by Davis etal. The United States
Bureau of Reclamation of data reported the major
practical applications in 1948 with the publication on
the use of fly ash in the construction of Hungry horse
dam. World wide acceptance of fly ash slowly
followed these early efforts but interest has been
particularly noticeable in the wake of the rapid
increase in the energy, cost (and hence cement cost)
that occurred during the 1970s. Thereby a number of
investigations were carried out both within and
outside this country on fly ash concrete. Conservation
of natural resources is the need of the hour
throughout the world. Steps to be adopted in this
direction include maximization of production of
energy consuming materials and bulk utilization of
industrial byproducts thereby making a major
contribution towards solving the global warming
problem and also by bringing down the levels of
environmental pollution. It is found that by using up
to 40% fly ash for M30 grade concrete proves most
effective and economical way of improving the
durability of concrete.
2.4Types of Fly Ash
Depending on the lime content fly ash is
classified into different categories. As per ASTM
standards it is classified as Class C and Class F.
Class C fly ash normally produced from the
combustion of lignite or sub-bituminous coals,
containing CaO higher than 10 percent and possesses
cementitious properties in addition to pozzolanic
properties.
Class F fly ash, normally produced from the
combustion of bituminous and anthracite coals,
containing CaO below 10 percent and possesses
pozzolanic properties only.
IS code has graded Fly ash based on their
physical properties and lime reactivity as Grade I and
Grade II.
Furthermore authors have classified fly ash
based on the boiler operations with two distinct
identities.
Low Temperature (LT) fly ash: Generated out of
combustion temperature below 9000
C. High
Temperature (HT) fly ash: Generated out of
combustion temperature above 10000
C.
The threshold temperature demarcates the
development of metakallonite phases in the case of
LT and the same constituent‟s form as reactive glassy
constituents in the case of HT fly ash. LT fly ash
though has a higher ignition loss (4-8%) is more
reactive in the early ages and is hence preferred for
precast building materials such as blocks or bricks. In
contrast the initial pozzolanic reaction is slow in HT
fly ash, which is accelerated with age. This property
together with a low ignition loss makes HT fly ash
more suitable in the cement and concrete industry.

Fig.2.1. Class F Type Fly Ash
Improvements in Concrete Properties by Using
Fly ash
With the use of fly ash based blended cements a
number of properties of concrete, both in fresh and
hardened states can be improved. The improvement
can be categorized in the following three main areas:
1. Benefits due to continued hydration of cement –
pozzolanic mixture leading to,
 Increased long term strength
 Reduced heat of hydration
 Improved resistance to chemical attack.
2. Benefits due to reduced water demand resulting
in
 Reduced bleeding
 Reduction in shrinkage and creep
 Lower permeability
 The failure of moisture and gases to go
through the concrete, results in the durability
enhancement (N.Bhanumati Das &N.Kali
Das).
3. Benefits due to improved cohesion of paste
matrix, leading to
 Less segregation
 Fewer difficulties in concrete placement.
A. 2.3 Methods of Fly ash Disposal
(i) Wet disposal system:
Wet disposal system involves mixing the fly ash
with water and sluicing it to a settling tank or
dumping areas, near the plant. The above mode of
ash disposal is consider being cheaper and so widely
adopted availability of dry areas of waste land for
ponding and unrestricted water supply are no doubt
essential for satisfactory operation of mode.
(ii) Dry disposal system:
Drydisposal system involves removal of fly ash
in dry form either directly by screw feeders
discharging into transport vehicles from the hoppers
or by means of pneumatic conveying system for
further disposal. The dry fly ash may also be stored in
storage silos at the plant.
2.4 Characteristics of Indian Fly ash
2.4.1 Physical Characteristics of Fly ash
1) Fineness (I.S: 1727 - 1967) & (I.S: 3812 – 1966):
Fineness is defined by specific surface in cm2
/g and
is (1) determined by Blaine‟s air permeability method
as per procedure laid down in IS 1727 – 1967. (2)
Fineness can also be determined by “dry” or “wet”
sieving as per procedure laid down in IS 1727 –
1967.
1. Fineness of fly ash is a single important physical
characteristic which influences the activity of fly
ash more than any other physical factor.
2. The Indian fly ashes appear to be quite fine by
Blain‟s air permeability method.
3. The fineness is most important factor affecting
the “lime-reactivity” of a fly ash either with
cement or with lime when mixed separately.
4. The fineness of fly ash eminently affects its
water requirement, abrasion resistance to
freezing and thawing of concrete made with fly
ash.
2) Particle size
1. Its particlesranging in size from as 120 to less
than 1 micron in equivalent diameter.
2. The particle size distribution mainly influenced
the fly ash reactivity at early ages.
3) Particle shape
It contains spherical glassy particles (solids or
hollow particles called cenospheres), irregularly
shaped (angular as well as rounded). The addition of
proper quality fly ash thus increases workability of
mix due to “ball bearing effect”, reduces “water
demand” and thereby increase strength smaller the
particle size higher the sphere content and more voids
are filled up and permeability reduced.
4) Density
The density of fly ash depends on the
constituents such as iron, silicon, aluminum, Silica
and carbon contents, tends to lower the density. It
generally varies between 1.97 to 2.89 g/cm3
, which is
approximately 2/3 of that of Portland cements.
5) Colour
The colour fly ash may range from light gray to
almost black depending on the type and quality of the
coal and combustion process.
6) Specific gravity

Table 2.1: Physical Properties of Indian Fly ash
The specific gravity of fly ash varies from source
to source. The specific gravity of solid fly ash
particles range from 1.97 to 3.02. A high specific
gravity is often an indication of fine particles and a
better fly ash as pozzolanic material.
Pozzolanic Reactivity or Lime Reactivity
a) Lime reactivity is the basic criterion to judge the
suitability of fly ash for all such users where in
development of strength is attained through
reaction of fly ash with lime.
b) The lime reactivity is greatly influenced by the
physico-chemical properties and mineralogical
composition of the fly ash. It increase with
increase in the contents of (1) fly ash fraction
passing 45-micron sieve; (2) SiO2+ Al2O3
percent and; (3) spherical glassy particles.
“Grinding”, „sieving‟, „recalcination‟ and
addition of certain chemical can admixtures
along with plasticizers.
Table2.2: Chemical Composition of Indian Fly
Ash
S.No Properties Range
1.
Percent passing 75 micron
I.S sieve
71.4 to
95.90
2.
Percent passing 45 micron
I.S sieve
45.0 to
88.80
3.
Fineness (Blain‟s air
method) (cm2
/gm)
3300 to
6250
4. Lime reactivity (kg/cm2)
50 to 62.40
Chemical Characteristics of Fly ash:
The major constituents of fly ash are oxides of
silicon, aluminium, iron, calcium and magnesium,
making up about 95% of the total composition (by
weight). Fly ash consists principally of fine glassy
spherical particles, or micro spheres, together with
some crystalline matter and a varying amount of un-
burnt carbon. These three pre-dominate elements in
fly ash-silicon, aluminium and iron, the oxides of
which together account for approximately 75% of the
material. Silicon is present partly in the crystalline
form of quartz (SiO2), and in association with
aluminium as mullite (3 Al2O3 2 SiO2), the rest in
glassy phase. The iron appears partly as the oxides –
magnetite and hematite (Fe2O3). The rest in glassy
phase carbon determined as loss-on-ignition is
present in fly ash in amounts, which which vary with
the efficiency of combustion. Indian fly ash contains
higher amount of SiO2, AbO3, unburnt carbon and low
Fe2O3, SO3.
2.5 Areas of Ash Utilization
Coal ash is versatile material which can be used
in a variety of applications are listed below:
1. Clay – fly ash bricks
2. Fly ash – sand lime bricks
3. Manufacture of sintered light weight aggregate
4. Use of manufacture of cement concrete and
mortar
5. Asbestos cement products
6. Use of fly ash in road construction
7. Embankment / back fills / land development
8. Use of fly ash in agriculture / soil amendment
9. Floor tiles and wall tiles
2.6 Advantages and Disadvantages of Fly ash
Concrete
The technical benefits of using fly ash in
concrete are numerous. The various advantages and
disadvantages found by different investigators in
India are summarized below.
Advantages
 Superior pozzolanic action.
 Reduced water demand (for fly ash with low
carbon content and high fineness).
 Improved workability.
 More effective action of water reducing
admixtures.
 Reduced segregation and bleeding.
 Increases setting time but remains within limits.
 Less heat of hydration.
 Less drying shrinkage.
 Improved molding qualities.
 Higher ultimate compressive, tensile, flexural
and bond strength.
 Higher ultimate modulus of elasticity.
 Decreased permeability and leaching.
 Reduces alkali – aggregate reaction.
 Improved freezing and thawing resistance.
 Improved resistance to sulphates.
 Cheaper construction due to replacement of
cement.
 Increase in creep with fly ash content up to 15%
is negligible.
S.No Properties Range
1. Silicon dioxide (SiO2) 37.15 – 66.74
2. Aluminium oxide (AbO3) 18.31 – 28.87
3. Iron oxide (Fe2O3) 3.23 – 21.94
4. Calcium oxide (CaO) 1.30 – 10.80
5. Magnesium oxide (MgO) 0.80 – 5.25
6. Sulphur trioxide (SO3) Traces – 2.91
7. Sodium oxide (Na2O) 0.1 – 0.2
8. Potassium oxide (K2O) 0.3 – 0.5
9. Loss-an-ignition (L.1.0.) 0.3 – 16.60

Disadvantages
 Lower early strength.
 Finishing difficulties with concretes containing
very high proportion of fly ash.
 Lower modulus of elasticity at early ages.
 Higher values of creep strains are anticipated.
 Reduced resistance to surface abrasion.
 Difficulty in handling fly ash as separate
material, which runs like liquid smoke.
Uses
Fly ash can be used for the following.
 For filing of mines
 For replacement of low lying waste land and
refuse dumps.
 As a replacement in cement mortar
 For air pollution control
 For production of ready mixed fly ash concrete.
 For building of roads and embankments.
 For stabilizing soil for road construction using
lime-fly ash concrete.
 For production of lime fly ash cellular concrete.
 For construction of rigid pavements using
cement fly ash concrete.
 For production of precast fly ash concrete
building units.
 For production of sintered light weight aggregate
and concrete.
 For making lean-cement fly ash concrete.
2.7 Role of Fly ash in Improving the Quality of
Concrete
1) Workability
Presence of fly ash particles in concentration
causes better dispersion of cement flocks; increase
particulate packing and a type of ball bearing effect
due to the round shape of the particles. These effect
result in improved workability and reduced water
demand; the consensus amongst researchers is that
fly ash reduces water demand of concrete for the
same slump. An approximate norm is that 10 percent
of fly ash replacement is equivalent to increase the
water content by 3 percent so far as workability is
concerned.
2) Air Entrainment
Air entrainment in fresh concrete is desirable
property for stability against freeze – thaw attack, a
normal phenomenon in cold climate. Fly ash is
believed to reduce their air content in fresh concrete,
particularly when more than 20 percent fly ash is
used. The reduction in air content is approximately 2
percent when fly ash content is increased from 0 to
50 percent for concrete to be used to extreme cold
climate.
3) Strength
For ultimate compressive strength of concrete
made with cement in combination with pozzolanas
like Fly Ash, two parameters are most important; the
level and age of concrete. With fly ash inclusion, the
rate of pozzolanic reaction is comparatively slower,
therefore, when compressive strength at 7 and 14
days is slower, they are nearly equal to those
reference concrete at 28 days and beyond 28 days the
strengths are higher.
4) Creep
For the same 28 days design strength, fly ash
concrete exhibits lower creep than
Portland cement concrete. The reason for lower creep
is higher ultimate strength of concrete.
5) Permeability
Permeability is a major factor in deterioration of
concrete, as more permeable the concrete is, the more
will be the increase of liquids and gases into the body
of concrete. Fly ash cause dense packing and
increased hydration of cement and pozzolanic
reaction (though delayed in case of fly ash) reduces
permeability. The presence of fly ash leads to greater
precipitation of cement gel produced than that with
Portland cement alone and more effectively block the
porous in concrete thus reducing its permeability.
The actual extent of reduction depends on many
factors like water to cementations material ratio;
aggregate grading compaction, efficiency of curing,
and the quality of extent of pozzolanas.
6) Effect of Carbonation
Rate of carbonation (penetration of atmospheric
carbon oxide) into concrete and reacting with Ca
(OH2) depends mainly on permeability of concrete.
Low permeability means slow rate of penetration of
CO2 changes the pH of the concrete and so
carbonation is lesser. The lesser degree of
carbonation slows the corrosion of steel.
7) Effect of Chlorides
It has been observed and shows that fly ash
concrete is better than OPC concrete in terms of its
ability to reduce the supply of chloride ions
responsible for corrosion of steel.
8) Effect on Resistance to Abrasion
Abrasion resistance of fly ash and OPC concrete
is a function of strength. The abrasion of fly ash
concrete was found to be higher for mixes with less
than 40 MN / Sq m. and lower than OPC concrete
mixes for strength in excess of 40 MN / Sq m.
9) Effect of Freezing And Thawing
Concrete containing fly ash have been reported
to have less resistance to the effect of freezing and

thawing. The use of super plasticizers and air
entraining agents improves the performance of fly
ash concrete.
10) Bleeding
The dispersion obtained by fly ash is stable. This
also results in a greater restriction for movement of
free water in plastic concrete and consequently
reduces bleeding.
11) Setting Time
Mixing of fly ash in concrete maintains
workability for longer period because of retardation
of initial hydration of tricalcium silicate and
tricalcium aluminate.
12) Heat of Hydration
Due to less cement content there is a less heat of
hydration very efficient in reducing temperature rise
and eliminating thermal cracks.
13) Alkali-Silica Reaction
Alkali condition in concrete so long as lime is
not leached out tends to maintain a protective film of
ferrous hydroxide on steel surface. This prevents easy
prevention of water and oxygen to further corrode the
surface since fly ash acts as alkali diluting, hence it
reduces the risk of damage due to alkali-silica
reaction.
14) SulphateReaction
Carbon in fly ash would appear by theoretical
consideration to be much more significant in concrete
than Sulphur. However, the usual low specification
limits on fly ash makes the percentage concrete so
small that is well dispersed. Its effect on the electrical
conductivity should quite negligible.
Introduction
This chapter describes the materials used and the
experimental work carried out to study the
performance of fly ash replaced concrete mixes with
different percentages of fly ash in comparison with
ordinary Portland cement (OPC) concrete.
The properties of materials used in this
investigation to produce the different mixes are
presented in detail, followed by the mix design which
includes the selection of concrete making ingredients
and blending proportions. The mixing procedure and
curing regimes used are also presented. The overall
experimental programme, which was implemented in
the investigation, is given. The specifics of the tests
carried out for each property studied are presented in
their respective chapters. Finally a description of the
means to study the interrelationships between the
different variables in the investigation is presented.
III. Materials
The same types of OPC, Fly ash, fine and coarse
aggregates have been used throughout the
investigation.
3.1. Cement
The most common cement used in construction
is ordinary Portland cement confirming to IS-
8112_1989.This type of cement is typically used in
construction and is readily available from a variety of
sources. The cement is fresh and uniform colour.
The cement is free from lumps and foreign matter.
The Blains fineness is used to quantity the surface
area of cement. The surface area provides a direct
indication of the cement fineness. The typical
fineness of cement ranges from 350 to 500sq.m/Kg.
The type of cement used all throughout the
experiment was Ordinary Portland Cement of grade
53 (OPC-53). This is the most common type of
cement used in general concrete construction where
there is no exposure to sulphates in the soil or in the
ground water.
3.2.1 Physical properties of Cement:
The cement used for the present work is
ORDINARY PORTLAND CEMENT (OPC) of
grade 53. The following tests as per IS: 4031-1988 is
done to ascertain the physical properties of the
cement. The results of the tests are to be compared
with the specified values in IS: 4031-1988.
Table 3.1 physical properties of cement Fly ash
Fly ash is a by-product of the combustion of
pulverized coal in thermal power plants. The dust-
collection system removes the fly ash, as a fine
particulate residue, from the combustion gases before
they are discharged into the atmosphere. Fly ash
belonging to class-F obtained from Vijayawada
thermal Power Station in Andhra Pradesh was used in
the present investigation.
Table: 3.4 Physical Properties of Fine Aggregate
S.No Property
Experimental
Values
1. Fineness of cement 6.50%
2. Specific gravity 3.10
3. Normal Consistency 29%
4. Initial Setting Time 50 min
5. Final Setting Time 320 min
S.No Property Value
1. Specific gravity 2.61
2. Fineness modulus 2.70
3.
Bulk Density Loose
Compacted
16.20 kN/m3
17.20 kN/m3
4. Grading Zone-II

Advantages of Fly ash:
 It reduces the water requirement and improves
paste flow behavior.
 Improves workability
 Increases cohesion, pump ability, finish ability
and flow properties
 Reduces heat of hydration, Segregation and
bleeding
 Enhances durability
 High resistance against chemical attack by
sulphates, soil and sea water
 Less shrinkage and creep
Physical properties are presented in Table 3.2.
Properties of Fly ash collected at Vijayawada
Thermal Power Station.
Table: Physical Properties of Fly Ash
S.No Properties Result
1. Specific Gravity 1.975
2. Fineness Modulus 1.195
Table: Chemical Analysis of Fly ash
S.No Property Formula
Test results
obtained
from plant
1. Silicon Dioxide Sio2 59.04
2.
Aluminum
Oxide
Al2O3 34.08
3. Iron Oxide Fe2O3 2.0
4. Lime Cao 0.22
5. Sulphur Trioxide SO3 0.05
6.
Magnesium
Oxide
MgO 0.43
7. Alakalies NA2O 0.5
8. Alakalies K2O 0.76
9. Loss of ignition LOI 0.63
3.2.2 Water
Potable water available in strength of materials
laboratory was used throughout the investigation.
3.2.3 Aggregates
3.2.3.1 Fine aggregate
Fine aggregates can be natural or manufactured.
The grading must be uniform throughout the work.
The moisture content or absorption characteristics
must be closely monitored. The fine aggregate used is
natural sand obtained from the river Godavari
conforming to grading zone-II of table 4 of IS: 383-
1970. The results of various tests on FA are given in
Table 3.4&3.5.
Coarse aggregate
Coarse aggregate is the strongest and least
porous component of concrete. It is also a chemically
stable material. Presence of coarse aggregate reduces
the drying shrinkage and other dimensional changes
occurring on account of moisture. In the present
study locally available blue granite crushed stone
aggregates of maximum size 20mm was used and
tests were carried out as per IS 2386:1986(111), its
specific gravity is 2.78.
Steel
Steel used is high yield strength deformed (HYSD)
bars yields strength of 415 N/mm2
. For each beam 8
mm and 10mm ф longitudinal reinforcement is
adopted and 6mm diameter M.S bars are used as
vertical stirrups.The steel bars used are free from
dust, rust or any organic matter. Oil etc at the time of
use.
3.3 Mix design procedure
The proportioning of a concrete mixture is based on
determining the quantities of the ingredients which,
when mixed together and cured properly will produce
reasonably workable concrete that has a good finish
and achieves the desired strength when hardened.
This involves different variables in terms of water to
cement ratio, the desired workability measured by
slump and cement content and aggregate proportions.
The mix is designed to target strength of 36.6 mpa, of
M30 Grade. Mix design is done according to Indian
standard recommended method of concrete mix
design IS 10262-1982.
3.3.1 Mix proportions
The nominal grade of concrete used in this
investigation is M30. The mix design is based on
strength criteria and durability criteria suitable for
mild environment. The ratios by weight of cement,
fine aggregate and coarse aggregate are obtained
using the equations given in IS 10262-1982. These
proportions are maintained strictly same throughout
the casting process to obtain a uniform standard and
workable concrete mix. Six cubes are cast for mixing
process and jested for compressive strength 14 days
curing.
The mix design proportions are 1:1.34:2.88 and W/C
ratio is 0.43.
Casting and Curing
After mixing, the concrete was placed in pre-
oiled moulds. Curing is done by ordinary water
curing for 14 days respectively.
Table 3.5: Fly ash replacement proportions
Mix id Cement Fly ash Total powder
Kg/m3
% Kg/m3
% Kg/m3
Mix 1 100 420 0 ------ 420
Mix 2 80 336 20 84 420
Mix 3 70 294 30 126 420
Mix 4 60 252 40 168 420
Workability Tests
Fresh concrete or plastic concrete is a freshly
mixed material which can be moulded into any shape.
The relative quantities of cement, fly ash, aggregates

and water mixed together, control the properties of
concrete in the wet state as well as in hardened state.
IV. Slump Cone Test
Slump test is the most commonly used method of
measuring consistency of concrete which can be
employed either in laboratory or at site of work.
The apparatus for conducting the slump test
essentially consists of a metallic mould in the form of
a cone having the internal dimensions as under:
Bottom diameter : 20cm
Top diameter : 10cm
Height : 30cm
For tamping the concrete a steel tamping rod
16mm diameter, 0.6 meter long is used. The internal
surface of the mould is thoroughly cleaned and freed
from superfluous moisture and adherence of any old
set concrete before commencing the test. The mould
is placed on a smooth, horizontal, rigid and non-
absorbent surface.
The mould is then filled in four layers, each
approximately ¼ of the height of the mould. Each
layer is tamped 25 times by the tamping rod taking
care to distribute the strokes evenly over the cross
section. After the top layer has been rodded, the
concrete is struck off level with a trowel and tamping
rod. The mould is removed from the concrete
immediately by raising it slowly and carefully in
vertical direction. This allows the concrete to subside.
This subsidence is referred as slump of concrete. The
difference in level between the height of the mould
and that of the highest point of the subsided concrete
is measured. This difference in height in mm is taken
as slump of concrete.
In my investigation I am conducting slump cone
test for M30 grade concrete with percentage of fly
ashes are 0%, 20%, 30% and 40
Fig.4.1. Experimental Set Up For Slump Cone
Test
Table 4.1: Slump cone results for different
percentages of fly ash
4.1.2 Compaction Factor Test
Compaction factor measures the workability in
an indirect manner by determining the degree of
compaction achieved by a standard amount of work
done by allowing the concrete to fall through a
standard height.
The sample of concrete to be tested is placed in
the upper hopper up to the brim. The trap door is
opened so that the concrete falls in the lower hopper.
Then the trap door of the lower hopper is opened and
the concrete is allowed to fall into the cylinder. In
the case of dry mix it is likely that the concrete may
not fall on opening the trap door in such a case a
slight pocking by rod may be required to set the
concrete in motion. The excess concrete remaining
above top level the cylinder is then cut off with the
help of plain blades supplied with the apparatus. The
surface of the cylinder is wiped clean and weighed.
This weight is known as “Weight of partially
compacted concrete”.
The cylinder is emptied and then refilled with the
concrete from the sample in 3 layers. The layers are
heavily rammed or preferably vibrated so as to obtain
full compaction. The surface of the fully compacted
concrete is then carefully struck off and the cylinder
is weighed. This weight is “weight of fully
compacted concrete”. Compaction factor is the
ratio of Weight of partially compacted concrete to
weight of fully compacted concrete.
In my investigation I am conducting compaction
factor test for M30 grade concrete with different
percentage of fly ashes are 0%, 20 %, 30% and 40%.
Fig.4.2. Experiment for Compaction Factor Test
Table 4.2: Compaction Factor Results for
Different Percentages of Fly Ash
Mix id Percentage
of fly ash
Compaction factor
value
Mix 1 0 0.83
Mix 2 20 0.856
Mix 3 30 0.92
Mix 4 40 0.955

Fig 4.B Variation of Compaction Factor Value
with Different Percentages of Fly Ash
4.1.2.1: Results and discussions
 The increase of percentage of fly ash there is
increase in workability
 The increase in percentage fly ash compaction
factor value increases. Thus represents increase
in workability.
V. Conclusions
Workability:
 The workability of concrete increased with
increase in addition of mineral admixtures (Fly
ash) up to 40 percentages.
Compressive strength:
 The Compressive strength is maximum for
40 percent cement replaced by fly ash concrete mix.
Load Vs displacement of cubes:
 40 % fly ash based concrete displacement
behavior is almost same as that of traditional
concrete.
Flexural strength:
 With The increase in percentage of fly ash
flexural strength in reinforced concrete beams
also increases. But if we increase depth of clear
cover the flexural strength value decreases.
Load Vs displacement of beams Reinforcement is
same (without design)
 When reinforcement is same (without design) for
5mm, 10mm and 15mm clear covers having load
carrying capacity is almost same for 40 % fly ash
replaced Concrete.
 40 % fly ash replaced concrete has high load
carrying capacity.
 But 30 % fly ash replaced concrete is good in
ductility.
Load Vs displacement of beams with deigned
reinforcement
 When reinforcement is different (designed
reinforcement provided) for 10mm, 15mm, and
20mm clear cover concrete beams 40 % fly ash
replaced concrete has high load carrying capacity
and good in ductility
Bending stress Vs crack width of beams with same
reinforcement (without design)
 40 % fly ash replaced concrete is far better to
control crack width when compared to traditional
concrete in case of 10mm, 15mm and 20 mm
clear covers.
 In case of 20 mm clear cover crack width is less
as compared to 10mm and 15mm clear covers.
Bending stress Vs crack width of beams with
different reinforcement (with design)
 40 % fly ash replaced concrete is far better to
control crack width when compared to traditional
concrete.
VI. Recommendation for Future Work
The tested beams are rehabilitated using different
techniques of restoration using concepts of epoxy
injection, mechanical stiffening and composite
wrapping techniques. The restored beam specimens
are subjected to reload and their capacity to withstand
the flexural stresses after restoration was studied. The
effectiveness of different methodologies was
reported. Further non destructive evaluation of the
beam specimen is carried out using impact hammer
tests and ultrasonic pulse velocity to study reliability
of the non destructive evaluation techniques in
condition assessment of the rehabilitated beam
specimen.
REFERENCES
[1.] ACI committee Report 226, BR 8, Use of fly
ash in concrete. ACI material journal.
Sept/Oct. 1987.
[2.] JOSHI, R.C., and LOTHLA, R.,” Fly ash in
concrete production, properties and uses”.
[3.] GOPALAKRISHNAN.S, RAJAMANE,
N.P., et al.,”Effect of Partial; Replacement
of cement with fly ash on the strength and
durability of HPC”, The Indian Journal, May
2001, pp335-341.
[4.] S.C. GUPTA, V.K. MEHROTRA and
S.C.JAIN(1988) use of fly ash to produce
strong and durable concrete.
[5.] PRASAD. M.M., and KUMAR,
VIRENDRA, “Flexural and split tensile
strength of fly ash- silica fume concrete”,
proceedings of the INCONTEST 2003,
september 2003, coimbatore, India;pp.217-
223.
[6.] DAM. B.K. and BASU. D., “Effect of fly
ash on structural changes during hydration
of cement and concrete- An overview” ,

ICFRC national seminar on HPCC, 28-29
december 2000, Chennai, India; SFC3-9.
[7.] BILODEAU.A and MALHOTRA. V.M,
1991, Mechanical Properties and deicing
salts scaling resistance of concrete
incorporating high volume of ASTM class F
fly ashes from three different sources.
CANMET.Energy, Mines and Resources,
Ottowa, MSL Division Report 9-17 (OP&J).
[8.] DESAI, J.P., “Construction and
Performance of High Volume Fly Ash
Concrete Roads in India, ACI SP-
221,V.M.Moalhotra, ed., 2004, pp.589-603
[9.] GANESH BABU.K, SIVANAGASWARA
RAO G.S “Effective Fly Ash in Concrete”,
cement concrete compose 1993; 15:223-9.
[10.] HAQUE.M.N, LANGEN B.W. and WARD
M.A; Properties of high fly ash concrete,
proceedings 11th
Australian road research
conference, Melbrone.1982. vol.II, Part
3.Pp. 70-79.
[11.] Concrete technology by M.S.SHEETTY.

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