1
A MNI-PROJECT REPORT
ON
PREPARING & TESTING OF FLY ASH SOIL BLOCKS
A Mini-Project Report submitted in partial fulfillment of the
Requirement for the award of degree of
Bachelor of Technology
In
Civil Engineering
By
R. KRISHNA REDDY (08091A0121)
M. JOSHNA RANI (08091A0114)
S. RAMUKUMAR (09095A0104)
M.RAJU (08091A0140)
M. PULLA REDDY (08091A0137)
UNDER THE ESTEEMED GUIDENCE OF
Mr. C. KRISHNAMA RAJU, M.E.
Associate Professor
Department of Civil Engineering
R.G.M College of Engineering & Technology, Nandyal-5180501
(Affiliated to J.N.T UNIVERSITY, ANANTAPUR, A.P INDIA)
(Approved by AICTE, Accredited by N.B.A New Delhi)
(Participated in World Bank Aided TEQIP-I)
YEAR (2008-2012)
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R.G.M College of Engineering & Technology, Nandyal-5180501
(Affiliated to J.N.T UNIVERSITY, ANANTAPUR, A.P INDIA)
(Approved by AICTE, Accredited by N.B.A New Delhi)
(Participated in World Bank Aided TEQIP-I)
DEPARTMENT OF CIVIL ENGINEERING
CERTIFICATE
This is to Certify that the Mini-Project entitled “PREPARING &
TESTING OF FLY ASH SOIL BLOCKS” that is being submitted by
R.KRISHNA REDDY (08091A0121), M.JOSHNA RANI (08091A0114),
S. RAMUKUMAR (09095A0104), M.RAJU (08091A0140) and M.PULLA
REDDY (08091A0137) in partial fulfillment for the award of degree of
Bachelor of Technology In Civil engineering to the Rajeev Gandhi
Memorial College of Engineering & Technology, Nandyal (Affiliated to
J.N.T UNIVERSITY, ANANTAPUR.) is a record of bonafide work carried
out by them under our guidance and supervision. The results
embodied in this Mini-Project have not been submitted to any other
University or Institute for the award of any degree.
GUIDE Head of the Department
Mr. C. KRISHNAMA RAJU Mr. C. KRISHNAMA RAJU
Associate Professor Associate Professor
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Acknowledgement
We express our deep sense of gratitude and honor to our Mini-
Project guide and HOD Sri C. Krishnama Raju M.E., Associate
Professor for his encouragement and inspired guidance throughout
the Mini-Project work for successful completion.
We are also highly grateful to our Principal Dr. T. Jayachandra
Prasad, Ph.D. for his kind help, inspiration & encouragement in
completing the Mini-Project work.
We would like to thank our Chairman Dr. M.
Santhiramudu, and our M.D. Sri M. Sivaram, for encouragement
and providing various facilities in completing the Mini-Project work.
R. KRISHNA REDDY (08091A0121)
M. JOSHNA RANI (08091A0114)
S. RAMUKUMAR (09095A0104)
M.RAJU (08091A0140)
M. PULLA REDDY (08091A0137)
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CONTENTS
CHAPTER1: INTROUCTION
CHAPTER2: PROPERTIES OF SOME BUILDING MATERIALS
2.1: Properties of fly ash
2.2: Properties of clay 2.3: Properties of silica 2.4: Properties of lime
2.5: Properties of Ordinary Portland cement
CHAPTER3: TYPE OF BRICKS 3.1: Common Burnt Clay Bricks 3.2: Sand Lime Bricks (Calcium Silicate Bricks)
3.3: Concrete Bricks 3.4: Fire Clay Bricks
3.5: Fly ash soil bricks
CHAPTER 4: PREPARATION OF FLY ASH BLOCKS
4.1: Preparation of mould 4.2: Procurement & Testing of Raw Material
4.3: Different Proportions of raw materials 4.4: Preparation of blocks
CHAPTER 5: RESULTS
CHAPTER 6: COMPARISION OF RESULTS
CHAPTER 7: CONCLUSION
CHAPTER 8: SCOPE OF FEATURE WORK
CHAPTER 9: REFERENCES
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TABLE N0: Page No.
1.1……………………………………………………………..8
1.2……………………………………………………………..8
2.1…………………………………………………………….12
2.2…………………………………………………………….12
2.3…………………………………………………………….13
2.4…………………………………………………………….21
2.5…………………………………………………………….21
3.1…………………………………………………………….28
4.1…………………………………………………………….29
4.2…………………………………………………………….29
4.3…………………………………………………………….30
5.1…………………………………………………………….34
5.2…………………………………………………………….35
5.3………………………………………………………….…36
6.1………………………………………………………….…38
FIGURES NO:
3.1……………………………………………………………24
3.2…………………………………………………………....26
3.3…………………………………………………………….27
4.1…………………………………………………………….31
4.2………………………………………………………….…31
4.3………………………………………………………….…32
4.4…………………………………………………………….32
4.5………………………………………………………….…32
4.6………………………………………………………….…32
4.7………………………………………………………….…32
5.1………………………………………………………….…33
5.2………………………………………………………….…33
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GRAPHS NO:
4.1…………………………………………………………….30
5.1…………………………………………………………….34
5.2…………………………………………………………….35
5.3…………………………………………………………….36
5. 4……………………………………………………………37
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ABSTRACT
The demand for buildings (utilized for living, offices etc) is
increasing day by day with increasing population and needs of the
people. Due to this the demand for bricks also increases. Steel,
cement, glass, aluminum, plastics, bricks, etc. are energy intensive
materials. For sustainable development energy efficient and eco-
friendly materials are needed.
In the present mini-project titled “Preparation & Testing of Fly
ash soil Blocks” the Fly ash soil Blocks using soil, fly-ash, sand,
quarry dust and lime in different proportions are prepared, tested &
results are reported. For all the proportions the 28 day compressive
strength is more than 2.5 MPa. These blocks are energy efficient and
eco-friendly because blocks are water cured and fly ash is industrial
waste.
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1. INTRODUCTION:
The demand for buildings (utilized for living, offices etc) is
increasing day by day with increasing population and needs of the
people. Due to this the demand for bricks also increases. Projected
demand for building materials like bricks, steel and cement consumed
in bulk quantities is given in table 1.1. (Ref.1).
Table 1.1: Projected demand for building materials
Material 2000 2020
Bricks(No’s) 150x109 246x109
Structural steel
(tonnes)
11x106 30x106
Cement (tonnes) 96x106 255x106
Steel, cement, glass, aluminum, plastics, bricks, etc. are energy
intensive materials, commonly used for building construction.
Generally these materials are transported over great distances. Energy
(fossil fuel energy) spent in transportation of some of these building
materials using trucks is given in table 1.2. (Ref. 1).
Table 1.2: Energy in transportation of Building materials
Building materials Unit Energy in transportation for
100km(MJ)
Bricks m3 200
Sand m3 175
Cement Tonne 100
Steel Tonne 100
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Extensive use of these materials can drain the energy resources
and adversely affect the environment. On other hand, it is difficult to
meet the ever growing demand for buildings by adopting only energy
efficient traditional materials (like mud, thatch, timber etc.) and
construction methods. Hence, there is a need optimum utilization of
available energy resources and raw materials to produce simple,
energy efficient, environment friendly and sustainable building
alternatives and techniques to satisfy the increasing demand for
buildings.
Some of the guiding principles in developing the sustainable
alternative building technologies can be summarized as follows:
Energy conservation; Minimize the use of high energy materials;
Concern for environment, environment friendly technologies; Minimize
transportation and maximize the use of local materials and
resources; Decentralized production and maximum use of local skills;
Utilization of industrial and mine wastes for the production of building
materials; Recycling of building wastes, and use of Renewable energy
sources.
Building technologies manufactured by meeting these principles
could become sustainable and facilitate sharing the resources
especially energy resources more efficiently, causing minimum
damage to the environment.
In the light of the above, the present mini-project titled
“Preparation & Testing of Fly ash Soil Blocks” is considered. The Fly
ash Soil Blocks are prepared using soil, fly-ash, sand, quarry dust
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and lime in different proportions, tested & results are reported. These
blocks are energy efficient and eco-friendly because blocks are water
curried and fly ash is industrial waste.
The present work is organized into different chapters.
Chapter 2 discusses about properties of some building
materials.
Chapter 3 discusses about different types of bricks.
Chapter 4 discusses about Preparation of Fly ash Soil Blocks.
Chapter 5 discusses Results.
Chapter 6 compares the results with brick other blocks.
Chapter 7 presents conclusions.
Finally scope of future work & references are reported.
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2: PROPERTIES OF SOME BUILDING MATERIALS
2.1: Properties of fly ash:
The quality of fly ash is governed by IS 3812-part 1-2003. The BIS
specification limit for chemical requirement are given in table 2.1 and
2.2 (IS 3812-2003). High fineness, low carbon content and good
reactivity is the essence of good fly ash. Since fly ash is produced by
rapid cooling and solidification of molten ash, large portion
component comprising fly ash particles are in amorphous state. The
amorphous characteristics greatly contribute to the puzzolana
reaction between cement and fly ash. One of the important
characteristics of fly ash is the spherical form of the practices. This
shape of particle improves the flow ability and reduces the water
demand. The stability of fly ash could be decided by finding the
density of fully compacted sample.
ASTM broadly classifies fly ash into two classes.
Class F: Fly ash normally produced by burning anthracite or
bituminous coal. Usually has less than 5% coal class F fly ash has
Puzzolana properties.
Class C: Fly ash normally produced by burning lignite or sub-
bituminous. Some class C fly ash may have CaO content in excess of
10% in addition to puzzolana properties. Class C fly ash also
possesses cementations properties.
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Table 2.1: Chemical requirement (Ref.2)
Sl.no (1)
Characteristic (2)
Requirement (3)
(1)
(2) (3)
(4) (5)
(6)
(7) (8)
Silicon dioxide (SiO3) plus aluminum oxide (Al2O3)plus iron oxide (FeO) percent by mass,
Min Silicon dioxide (SiO3) percent by mass, Min Reactive silica in percent by mass, Min
Magnesium oxide (MgO) percent by mass, Max Total sulphur as sulphur trioxide(SO3) percent by mass, Max
Available alkalis, as sodium oxide (Na2O)percent by mass, Max
Total chloride in present by mass, Max Loss on ignition, percent by mass, Max
70.0
35.0 20.0
5.0 3.0
1.5
0.05 5.0
Limits regarding moisture content or fly ash shall be as agreed to
between the purchaser and the supplier. All tests for properties
specified shall, however, are carried out on over dry samples.
Table 2.2: Physical requirements (Ref.2)
Sl. No (1)
Characteristic (2)
requirement grade of fly ash І ІІ
(3) (4)
(1) (2)
(3)
(4)
Fineness specific surface in m2/kg by Blaine s permeability method. Min Lime reactive –average compressive
strengths in n/mm2, min Compressive strength at 28 days
n/mm2 , min
Soundness by autoclave test
expansion of specimens, percent, max.
320 250 4.5 3.0
Not less than 80
percent of the strength of the corresponding plain
cement cubes 0.8 0.8
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Fly ash, when tested in accordance with the methods of test
specified in IS: 1727-1967, shall conform to the chemical
requirements give in table 2.3.
Table 2.3: Illustrative properties of fly ash from different sources (Ref.3)
Property/ source A B C D E
Specific gravity 1.91 2.12 2.10 2.25 2.146 to 2.429
Wet sieve analysis
(percentage retained on no 325 BS sieve)
16.07
54.65
15 60
5.00
51.00(dry)
Specific surface (cm2/g balance)
2759 1325 2175 4016 2800to3250
Lime reactivity (kg/sq.cm)
Chemical analysis
86.8
56
40.03
79.3
56.25 70.31
Loss on ignition percentage 5.02 11.33 1.54 7.90 1-2
Si02 50.41 50.03 63.75 60.10 45-59
S03 1.71` - - - 45-59
P208 0.31 - - - Trace to 2.5
Fe203 3.34 10.20 30.92 6.40 0.6-4
Al303 0.66 18.20 - 18.64 23.33
Ti2 0.84 - - - 0.5-1.5
Mn2O3 0.31 - - - -
CaO 3.04 6.43 2.35 6.3 5-16
MgO 0.93 3.20 0.95 3.6 1.5-5
Glass content: highly variable within and between the samples but generally below 35%
Nearly 110 million tones of fly ash are generated in 2010 in
India from thermal power plants set up at various places. Processes
have been developed for production of clay fly ash bricks and bricks
using fly ash and sand with addition of lime or chemical with or
without autoclaving
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2.2: Properties of Clay:
There are two types of clays that are recognized, the silicate clays of
temperate regions and the iron and aluminum hydroxide clays found
in the tropics and semi tropics. The great agricultural regions of the
world are dominated in a large degree by clays of a siliceous nature.
All clay particles are crystalline and not amorphous as was originally
supposed.
Each clay particle regardless of its individual shape is made up of
sheet like molecules or units, held loosely together. Clay particles will
also show considerable variation in size. These units are quite definite,
usually changing in size only by lateral extension. A clay particle
might be visualized by comparing it with a piece of mica as the flakes
of the latter represent the plate like molecules or units.
Clay particles because of their fineness of division must expose a
large amount of external surface. There are also internal surfaces as
well, the sum of which usually greatly exceeds that of a superficial
character.
It has been shown that clay particles are composed of two distinct
parts, the inner, porous, and enormously larger insoluble acidosis, or
micelle, and the outer and more or less dissociated swarm of cat ions
with variable amounts of water of hydration. Since these absorbed cat
ions are usually rather easily displaced, they are spoken of as
exchangeable ions. This replacement, called ionic exchange, or more
15
commonly Base Exchange, is one of the most important of all soil
phenomena.
Calcium and magnesium are the absorbed metallic cat ions held in
the largest amounts by the siliceous clays of most natural soils. Since
so much of the total calcium is replaceable, its activity is assured. The
main concern, therefore, is the amount present thus we use the
practice of liming. With potash the total amount is often ample, but
the proportion active is exceedingly small.
Two groups of clay are commonly recognized, the kaolin and the
montmorillonite. The molecules of the kaolin are thought to be
composed of two sheets or plates, one of silica and one of alumina.
The second group, the montmorillonite, is composed molecularly of
two silica sheets and one of alumina. The molecules of these clays are
less firmly linked together than those of the kaolin group and are
usually further apart.
In discussing the mineralogical nature of silicate clay, it must not
be forgotten that other minerals besides the ones mentioned are
present, either as mere accessories or as an important part of the
colloidal complex. Of these, the hydrated oxides of silicon, iron, and
aluminum should be mentioned. While these probably occur but
sparingly in temperate-region soils, the latter two are especially
important in tropical and semitropical regions, giving rise to what are
spoken of as late rite soils. The silicate clays often contain a larger
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and larger admixture of colloidal iron and aluminum oxides. The red
and yellow soils of our southern states are very good evidence of this
transition.
2.3: Properties of silica:
SILICA is the most abundant mineral found in the crust of the
earth. It forms an important constituent of practically all rock-forming
minerals. It is found in a variety of forms, as quartz crystals, massive
forming hills, quartz sand (silica sand), sandstone, quartzite, Tripoli,
diatomite, flint, opal, chalcedonic forms like agate etc., and in with
numerous other forms depending upon color such as purple quartz
(amethyst), smoky quartz, yellow quartz or false topaz (citrine), rose
quartz and milky quartz. Only pure quartz crystal or rock crystal,
untwined, clear, free from any inclusion, has an important property.
It expands (mechanically) under the influence of electric current
and conversely pressure induces a measurable electric current. This
property is known as piezoelectricity. The current thus developed is
called piezoelectric current.
This property resulting from the asymmetry of its atomic groups
makes quartz an effective transducer for converting electrical energy
into mechanical energy and vice-versa. This property in quartz
crystals was discovered in 1880-82 by Pierre and Jacques Curie and
remained a laboratory curiosity till in 1921 when W.G. Cady, a
physicist, discovered that quartz plates could be used to control the
frequency of wireless transmission circuits.
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This discovery marked the dawn of quartz crystal application in
modern communication equipments. A very thin plate of quartz is so
cut that the frequency of the oscillating circuit corresponds with the
quartz plate and when such plate is inserted in a radio receiving set or
radio transmitter it prevents frequencies from wandering and
deviation and greatly reduces interference.
Quartz plate is used in controlling frequencies in air and water
media as well. It is largely used in radio circuit, radar, ultrasonic and
in multiple telephone lines. Quartz plates keep the broadcast on the
right beam.
Quartz crystals cut into prisms, wedges and lenses are used for
microscopes and other optical instruments. Quartz wedge is the
commonest accessory which students use in the petro logical
microscope.
A number of other crystals giving piezoelectricity are known but
none compares with quartz. Chemically prepared Rochelle salt and
Barium titan ate have been found good substitutes for piezoelectric
quartz.
However, the crystal - quartz because of its chemical and physical
stability and high elasticity has remained indispensable so far. The
consumption of quartz plate pieces has tremendously increased with
the increase in the manufacture of modern receiving sets.
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2.4: Properties of lime:
Lime:
Lime is a generic term, but by strict definition it only embraces
manufactured forms of lime – quicklime (CaO) and hydrated lime (Ca
(OH)2). It is, however, sometimes used to describe limestone products
which might be a cause of confusion.
The raw material for all lime-based products is a natural stone:
limestone, which is composed almost exclusively of calcium carbonate
(CaCO3). When limestone contains a certain proportion of magnesium,
it is called dolomite, or dolomites’ limestone (CaMg (CO3)2). It is widely
geographically available all over the world (the Earth’s crust contains
more than 4% calcium carbonate) and also widely used for many
different purposes. In the lime or dolomite production processes, the
blocks of limestone or dolomite obtained after blasting in the quarry
are crushed and sorted by size in screening plants. At this stage:
Part is used directly, for example as aggregates for road
construction, for concrete or other applications.
Part is ground to lime fertilizer or pulverized into limestone
powder, used in applications such as flue, Gas-cleaning, animal
feed or as fillers in many products (concrete, asphalt, carpet-
backing…).
The rest, high quality limestone with a defined particle size is
calcinated in a lime burning plant at a temperature of 900-1200°C, at
which temperature it is decarbonated in either vertical or rotary kilns
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fired with gas, oil, coal, coke or other fuels. During that process,
carbonate is converted into oxide (Cao or CaMgO) and CO2 is released.
The combustion phase is essential for obtaining a quality lime that
satisfies the required characteristics. First it is important to adjust
reactivity because the various applications require reaction times
(reaction of oxide with water) that can vary from a few seconds to more
than thirty minutes. In addition the products must possess precise
physical and chemical characteristics because of different standards
for certain applications. The quicklime obtained can be used as such,
or can be crushed, finely ground, or micronized depending on its
intended use. Quicklime can also be hydrated, i.e. combined with
water in a hydrator. The quantity of water added is about twice the
stoichiometric amount required for the hydration reaction. The excess
water is added to moderate the temperature generated by the heat of
reaction by conversion to steam. The end product is hydrated lime or
slaked lime (Ca (OH)2) in the form of a very fine powder suitable for a
variety of applications. Milk of lime and lime putty is produced by
slaking of lime with excess water. Slaking is done in both batch and
continuous slackers. The term milk of lime is used to describe a fluid
suspension of slaked lime in water. Milks of lime may contain up to
40% by weight of solids. Milk of lime with high solids content is
sometimes called lime slurry. Lime putty is a thick dispersion of 55 to
70% by weight of slaked lime in water. Lime paste is sometimes used
to describe semi-fluid putty.
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Multiple properties – manifold uses
Lime can be used for a wide range of purposes because of its
different characteristics:
Alkaline reaction of lime with water (neutralization,
coagulation, flocculation)
Forming of water insoluble calcium salts (precipitation of
heavy metals and sulphates)
Re-carbonation reaction with CO2 (hardening of plaster,
increase of acid capacity)
Pozzolanic reaction with silicates (forming of calcium
silicates)
Heat generation by contact of quicklime with water (drying,
pasteurization, disinfection)
While lime is one of the earliest industrial commodities known to
man, its production and uses have grown with the times, and it
continues to be one of the essential building blocks of modern
industry.
Properties of Ordinary Portland cement (OPC):
It is the most type of cement. Prior to 1987, there was only one
grade of OPC which was governed by IS 269-1976. After 1987 higher
grade cements were introduced in India. The OPC was classified in to
3 grades, namely 33 grade, 43 grade and 53 grade depending upon
the strength of cement at 28 days when tested as per IS 4031-1988. If
the 28 days strength is not less than 33Mpa, it is called 33grade
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cement, if the strength is not less than 43Mpa, it is called 43grade
cement and if the strength is not less than 53Mpa, it is called 53grade
cement. But the actual strength obtained by these cements at the
factory is much higher than the BIS specifications.
The physical and chemical properties of 33, 43 and 53 grade OPC
are shown in table
Table2.4: Physical properties (Ref.4)
Sl.
no
Type of
cement
(OPC)
Fineness Soundness by Setting time
(mts)
Compressive
strength (min. Mpa)
(m2/kg)Min.
Le chatelier
(mm) max.
Auto clave
(%) Max.
Initial min
Final
max.
3 days
7 days
28 days
1 33 grade 225 10 0.8 30 600 16 22 33
2 43 grade 225 10 0.8 30 600 23 33 43
3 53 grade 225 10 0.8 30 600 27 37 53
Table2.5: Chemical properties (Ref.4)
Sl.
no
Type of
cement
Lime
saturation factor (%)
Alumi
na iron Ratio
(%) Min.
Insolu
ble Residue (%)
Max.
Magne
sia (%) Max.
Sulphuric
Anhydride
Loss of
magnesia (%) Max.
1 33 grade
0.66 min.
1.02max.
0.66 4 6 2.5% max. When
C3A is 5 or less 3%
max. when C3A > 5
5
2 43
grade
0.66 min.
1.02max
0.66 2 6 2.5% max. When
C3A is 5 or less 3%
max. when C3A > 5
5
3 53 grade
0.8 min
1.02max.
0.66 2 6 2.5% max. When
C3A is 5 or less 3%
max. when C3A > 5
4
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3. TYPE OF BRICKS
There are various type of bricks used in masonry.
1. Common Burnt Clay Bricks
2. Sand Lime Bricks (Calcium Silicate Bricks)
3. Concrete Bricks
4. Fire Clay Bricks
5. Flay ash soil bricks
3.1: Common Burnt Clay Bricks
Clay bricks are fired bricks. These are formed by pressing in
moulds or by an extrusion and wire cutting process. Then these
bricks are dried and fired in a kiln.
3.2: Sand lime bricks
In the early 'eighties of the 19th century, Dr Michaels of Berlin
patented a new process for hardening blocks made of a mixture of
sand and lime by treating them with high-pressure steam for a few
hours, and the so-called sand-lime bricks are now made on a very
extensive scale in many countries. There are many differences of detail
in the manufacture, but the general method is in all cases the same.
Dry sand is intimately mixed with about one-tenth of its weight of
powdered slaked lime; the mixture is then slightly moistened with
water and afterwards moulded into bricks under powerful presses,
capable of exerting a pressure of about 60 tons per sq. in. After
removal from the press the bricks are immediately placed in huge
steel cylinders usually 60 to 80 ft. long and about 7 ft. in diameter,
and are there subjected to the action of high-pressure steam (120 lb to
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150 lb per sq. in.) for from ten to fifteen hours. The proportion of
slaked lime to sand varies according to the nature of the lime and the
purity and character of the sand, one of lime to ten of sand being a
fair average.
The following is an analysis of a typical German sand-lime brick:
silica (SiO), 84%; lime (Cao), 7%; alumina and oxide of iron, 2%;
water, magnesia and alkalis, 7%. Under the action of the high-
pressure steam the lime attacks the particles of sand, and a chemical
compound of water, lime and silica is produced which forms a strong
bond between the larger particles of sand. This bond of hydrated
calcium silicate is evidently different from, and of better type than, the
filling of calcium carbonate produced in the mortar-brick, and the
sand-lime brick is consequently much stronger than the ordinary
mortar-brick, however the latter may be made. The sand-lime brick is
simple in manufacture, and with reasonable care is of constant
quality. It is usually of a light-grey color, but may be stained by the
addition of suitable coloring oxides or pigments unaffected by lime
and the conditions of manufacture. Fig 3.1 shows the sand lime
bricks.
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Fig: 3.1sand lime bicks
3.3: Concrete bricks
Concrete brick is made from solid concrete. These bricks are used
to cover the facade of a home, build fences, and enhance the overall
beauty of a home's exterior. Bricks that are made from concrete come
in a number of styles and colors making them extremely popular
amongst homeowners. Concrete bricks also have many other
appealing attributes.
While regular brick does a fine job of insulating a home, concrete
brick tends to be a better insulation option. Traffic, airplanes, and
other outside noises are effectively muted, thanks to the solid concrete
that these bricks are made from. Other benefits of concrete brick
include better fire protection, less exterior home maintenance, and
lower energy bills. Bricks that are fashioned from concrete are
available in a number of different styles. Consumers can select from a
smooth, rough, textured, glossy, sandblasted, or stone finish. Various
manufacturers may also offer customized bricks according to a
consumer's specifications. In addition, hundreds of different color
25
options are available -- most manufacturers will customize bricks to
meet a homeowner's needs.
Concrete bricks are quickly becoming a popular alternative to
other home facade materials. While the cost of installing this type of
brick may be higher than the cost of installing other materials,
concrete brick will last a lot longer than most other substances. In
fact, concrete brick tends to mature with age creating a desired
timeless look.
While durable and attractive, these bricks are not indestructible.
Bricks made from concrete will generally last up to twelve years. After
this length of time has passed, small bits of brick may begin to break
off of each piece. At this point, certain bricks will have to be replaced,
though this can be done on an individual brick basis.
There are many positive aspects of these bricks, but there are also
some negative aspects. Concrete may shrink once it has been
installed. This often results in gaps between bricks, which can allow
outside water to seep into a home. Also, there is no way to prevent
color from leaking out of concrete, which may result in faded bricks.
Concrete brick is a very effective way to make a strong first
impression. When people walk up or drive by a home with concrete
brick, second glances are common reactions. If you own a home with
concrete brick as your exterior veneer, you already know this. If you
are planning on using it, be prepared to have your neighbors ask
26
questions while admiring the beauty of your concrete brick.
Concrete brick has more benefits than its striking visual qualities.
They deaden exterior noise, giving you and your family a buffer from
traffic noise, airplanes flying overhead and other various disruptions.
Fire protection is another benefit of concrete brick. Giving your family,
and the fire department, extra time is never a bad thing. You won't
have to worry about maintenance with concrete bricks finally;
concrete brick walls can improve the thermal mass qualities of your
exterior walls, thus improving your energy bills. Fig: 3.2shows the
Concrete brick.
Fig: 3.2 concrete bricks
3.4: Fire clay bricks
Fire clay exists at much depth below the surface and is usually
mined. Generally, Fire clays contain metallic oxides less than surface
clays and have more uniform chemical and physical properties.
Fire clay bricks are produced from Fire clay is used for
manufacturing of all sorts of refractory materials and due to its
alumina and silica content, it leads to the formation of highly heat
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resistant fireclay bricks. Normally, fireclay is clay that has higher
content of Alumina. Normally, alumina content in fire clay is 24 or
34% while the silica content is 50 or 60%.
Fire clay bricks are used for building construction including fire
place construction and huge industrial furnace construction. These
products are used in the core industries such as Steel Industry,
Aluminum Industry, Cement Industry, Ceramic Industry,
Electroplating Industry, Chemicals Plants, Dairy Plants, Fertilizers
Plants and Forging Plants. The fireclay bricks are highly useful in the
boiler and sugar industry, boiler cupola and steel foundry, cement
pre-heater cyclone, silicate furnace, boilers incinerators, cement kiln,
preheating zone and preheating furnace wall.
Fig: 3.3 fire clay bricks
3.5: Fly ash Soil Bricks
Fly Ash soil bricks are made of fly ash, lime, soil and sand. These
can be extensively used in all building constructional activities.
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Fly ash is used as main raw material to prepare fly ash soil blocks
because, it is being accumulated as waste material in large quantity
near thermal power plants and creating serious environmental
pollution problems, its utilization as main raw material in the
manufacture of bricks will not only useful in disposal but also help in
environmental pollution control to a greater extent in the surrounding
areas of power plants.
Also there is ever increasing demand for power generation in the
country. In our country major power is generated from thermal power
plants which are coal based and they generate fly ash as waste
product. The Table3.1 (Ref.5) shows the thermal power generation,
coal consumption and ash generation in India.
Table 3.1: Thermal power generation, coal consumption and ash
generation in India (Ref.5)
Year Thermal power generation (MW)
Coal consumption (MT)
Ash generation (MT)
1995 54,000 200 75
2000 70,000 250 90
2010 98,000 300 110
2020 137,000 350 140
The preparation and results of these blocks are discussed in next chapters.
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4. PREPARATION OF FLY ASH SOIL BLOCKS:
4.1 Preparation of mould
The mould is prepared with fly wood flanks having inner
dimensions of 305x143x100 mm.
4.2 Procurement & Testing of Raw Material
Fly ash from T.G Venkatesh power plant, Kurnool; soil from
Shanthi Ram Engineering College, Nandyal; Quartz dust from stone
quarry near Orvakallu, Lime from Nandyal are collected.
The specific gravity of soil, sand and quartz dust is determined by
using pychnometer and particle size distribution for fly ash, soil,
sand, quartz dust is determined by using dry sieve analysis method.
The results are shown in table 4.1, 4.2 and particle size distribution
curves in Graph 4.1.
Table 4.1: Specific Gravity
SNo Material Specific Gravity
1 Soil 2.38
2 Sand 2.56
3 Quartz dust 2.00
Table 4.2: Sieve Analysis
SNo Material % Gravel % Sand % Silt & Clay
1 Soil 10.37 88.73 0.90
2 Sand 0 99.66 0.34
3 Quartz dust 0 93.00 7.00
4 Fly Ash 0 96.20 3.80
30
Graph 4.1 patrical size distribution curves
4.3 Different Proportions of raw materials:
Five different proportions of raw materials are considered for
making the Fly ash Soil Blocks as shown in table 4.3. For first four
proportions 4 blocks are prepared and for fifth proportion 2 blocks are
prepared.
Table 4.3: Different Proportions
Sl. No Fly ash (%) Soil (%) Sand (%) Quartz dust (%) Lime (%) Water (%)
1 20 60 7 7 6 41
2 30 50 7 7 6 42.5
3 40 40 7 7 6 44
4 50 30 7 7 6 45
5 60 20 7 7 6 46
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4.4 Preparing of block:
The proportion of the raw materials (i.e. Fly ash, lime, sand, Soil
and quartz dust) are taken according to the table 4.3 into the pan and
mixed thoroughly. Then water is added about 40- 45% to get
workability and it becomes paste.
The paste is poured as 3 layers in to the mould, each layer is
tamped with tamping rod to avoid voids and this mould is shifted to
the C.B.R (California bearing ratio) for applying load up to 200 Kg on
the block. After loading, the block is removed carefully from the mould
then it is kept in open air up to 24 hours for drying and the block is
cured in presence of water for required days.
The step by step procedure for preparation of blocks as shown
figures: 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7.
Fig: 4.1 Mixing of raw mateials Fig: 4.2 Block paste
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Fig 4.3: Pouring paste in to the mould Fig4.4: C.B.R (for loading)
Fig: 4.5: Block with mould Fig 4.6: Removing the mould
Fig4.7: Fly ash soil blocks
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5. RESULTS:
The cured blocks are removed from the water and dried to open
air then the bricks are weighted, dimensions are noted to find
density of the blocks and these blocks are tested by using Universal
testing machine (U.T.M) to find the compressive strength of the fly
ash soil blocks.
Fig5.1: U.T.M machine Fig 5.2: Testing the block
The test results of blocks are shown in graphs 5.1, 5.2 & 5.3 for
3, 14, 28 days, and also maximum load and compressive strengths
for various proportions of blocks are shown in tables: 5.1, 5.2, and
5.3.
34
Table 5.1 FOR 3 DAYS
Bricks with different proportions
Maximum load (KN) Compressive strength (N/mm^2)
FSB1.1 21.87 0.5
FSB1.2 24.15 0.56
FSB2.1 27.6 0.64
FSB2.2 25.11 0.58
FSB3.1 27.03 0.6
FSB3.2 23.58 0.55
FSB4.1 23.95 0.56
FSB4.2 22.9 0.54
Graph 5.1: Compressive strength for 3 days
35
Table 5.2 FOR 14 DAYS
Bricks with different
proportions
Maximum load (KN) Compressive
strength (N/mm^2)
FSB1.3 73.95 1.73
FSB1.4 70.05 1.64
FSB2.3 91.68 2.16
FSB2.4 87.8 2.06
FSB3.3 83.73 1.94
FSB4.3 110.97 2.60
FSB5.1 112.38 2.64
Graph 5.2 Compressive Strength for 14 days
36
Table 5.3 FOR 28 DAYS
Bricks with different
proportions
Maximum load (KN) Compressive
strength (N/mm^2)
FSB3.4 114.7 2.67
FSB4.4 112.63 2.63
FSB5.2 119.28 2.78
Graph 5.3 Compressive Strength for 28 days
37
Graph 5.4 shows the variation of compressive strength for different
proportions for 3, 14, 28 days.
Graph5. 4 Variation of Compressive Strength
The following points are drawn from the above results.
For 3 days the compression strength of fly ash soil blocks is 0.5
to 0.6Mpa.
For 14 days the compression strength of fly ash soil blocks is
>1.7Mpa.
For 28 days the compression strength of fly ash soil blocks is >
2.5Mpa.
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6. COMPARISION OF RESULTS
Table 6.1: Compressive Strengths of various bricks
Sl. No Type of bricks Compressive strength
1 Common burnt clay bricks (Ref.6)
I. Class
II. Class
III. Class
Not less than 10.5Mpa.
Not less than 7.5Mpa.
>3.5Mpa.
2 Stabilized mud Bricks (Ref.1) 3- 4Mpa.
3 Fine concrete blocks (Ref.1) >3Mpa.
4 Fly ash soil blocks >2.5Mpa.
The Fly ash soil blocks have got less compressive strength
compared to bricks, stabilized mud bricks & Fine concrete blocks.
Hence these blocks can be used for partition walls, parapet wall &
temporary structures.
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7. CONCLUSION
The maximum compressive strength is 2.78 MPa for 5th
proportion (i.e. fly ash 60%, soil 20%, sand7%, quartz dust7%
and lime6%).
The increase in compressive strength from 3 to 14 days is about
1.1Mpa and from 14 to 28 days is about 0.8 Mpa.
As the fly ash content is increased the compressive strength of
fly ash soil blocks is also increases.
Emphasizes the need for using alternative materials for
protecting the Environment and for sustainable development.
40
8. SCOPE OF FUTURE WORK
1. The work can be extended by using cement in place of lime.
2. The work can be extended by increasing lime percentage.
3. The work can be extended by increasing the compressive
load during moulding of block.
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9. REFERENCES
1. Sustainable Building Technologies by B.V. Venkatarama Reddy,
IISc, Bangalore; CURRENT SCIENCE, VOL.87, NO 7, 10 OCTOBER
2004.
2. IS: 3812-part-1-2003.
3. IS: 1727-1967.
4. CONCRETE TECHNOLOGY BY M.S SHETTY.
5. CURRENT SCIENCE, VOL. 100, NO. 12, 25 JUNE 2011 IS 269-
1989
6. BUILDING MATEIALS BY S.K DHUGGAL
-
42
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