(DOC) mini project doc onProduction Of Fly Ash Bricks | Santhosh Goud

(PDF) A Brief Overview of Fly Ash Brick Production

Proceedings of XIII

th

International Mineral Processing Symposium – Bodrum-Turkey, 2012

3

The former Turkish standards TS 704, TS 705, TS 4563 and TS 4377 were abolished in

order to comply with the European standards and the new standard for bricks, TS EN 771-

1, was put into effect. Most of the producers have completed their compliance period to CE

standards (TUKDER, 2008).

Size of brick industry: There are 417 plants disseminated all over Turkey but in small

concentrations in the regions where the raw materials are easily supplied. Of 417 plants, 48

plants produce roof tiles, 8 plants produce roof tiles and bricks and the rest produce only

bricks. The total brick production capacity is 5 327 000 000 units/year which corresponds

to 15 981 100 tons/year (one unit is 3 kg). On the other hand, the total roof tile production

capacity is 609 000 000

units/year which corresponds to 1 522 500 tons/year (one unit is

2.5 kg). The total exports and imports between January and July 2008 were reported to be

20 727 582 $US and 3 535 962 $US, respectively (TUKDER, 2008).

METHODS OF FAB PRODUCTION

For more than two decades, researchers have been investigating the viability of using FA

for brick making. Prior to discussing them shortly, a simple classification of the methods

of manufacturing FAB must be done. Generally, two fundamentally different approaches

exist to make brick and other building products from FA. One is the traditional way of

brick making by firing the brick material except that the FA substitutes a portion of clay or

entire amount of clay in brick making. The other is based on the self cementing property of

Class C FA that contain a large amount of calcium. In this case, firing or heating in kilns is

not needed to obtain the final product. Instead, the bricks produced can be cured in the

same way concrete is cured. Therefore, hereafter, the bricks made from FA with different

clay replacing ratios fired at high temperatures such as 950-1200

o

C will be referred to as

fired FA bricks (FFAB) and the ones produced by making use of other means at ambient

temperatures rather than sintering will be referred to as non-fired FA bricks (NFFAB).

Methods of FFAB production: In this method, FA was used as a raw material to replace

brick clay partially with different replacement ratios or with 100% FA ratio.The mixture

of FA and clay were shaped and fired over 1100

o

C to obtain FFAB. There were number of

studies all reporting positive results meeting or overtaking required standards for traditional

clay bricks (Tütünlü and Atalay, 2001; Chou et al., 2006; Chou et al., 2001; Kute and

Deodhar, 2003; Lingling et al., 2005; Pimraksa et al., 2001; Kayali, 2005; Cengizler, 2008).

On the other hand, 100 % FA bricks manufactured byKayali’s process using technology

similar to conventional clay bricks were named Flyash Bricks (Kayali, 2005). A 100% class

‘F’ FA mixture was moulded into a brick (Flash Brick) and fired in a conventional kiln.

The finished brick was 28% lighter and 24% stronger than comparable clay bricks. Itis

reported that the Flash Brick competed on all technical levels with clay bricks. The use of

FFAB was authorized in number of countries such as Germany, the United Kingdom and

India (Lingbawan, 2009).

Methods of NFFAB production: The production of non-fired FA-sand-lime bricks:

The method is based on mainly CaO–SiO

2

–H

2

O (C–S–H) formation (Ball and Carroll,

1999; Baoju et al., 2001; Ma and Brown, 1997; Peng et al., 1999) due to the reaction taking

place between lime and silica in the presence of water. Calcium–silicate–hydrate is formed

by the reaction of Ca(OH)

2

, SiO

2

and H

2

O under pressurized steam at 125–200

o

C. In the

IJSRD — International Journal for Scientific Research {amp}amp; Development| Vol. 4, Issue 09, 2016 | ISSN (online): 2321-0613

Comparative Study on Fly Ash Bricks and Normal Clay Bricks

P.P. Gadling1 Dr. M.B. Varma2

1Student 2Professor

1,2Department of Applied Mechanics

1,2Government College of engineering Aurangabad (MH), India

Abstract This paper presents Fly Ash brick properties,

manufacturing process material required for preparing the

clay bricks and fly ash bricks as perIndian standard code

provisions, inspection and quality control. The textures of

the bricks with Fly Ash were very similar to that of clay

bricks; the sample with the additive contains spherical Fly

Ash particles. These particles of Fly Ash led to a reduction

in the density of the bricks and a substantial improvement in

their durability. Use of this additive could have practical

implications as a means of recycling and for achieving cost

savings in brick production. The absorption coefficient,

shape and size, density, weight, porosity, thermal

conductivity and compressive strength of Fly Ash bricks

compare with normal clay bricks that delivered good results.

From the present study, it can be concluded that Fly Ash

bricks used as an alternative to clay bricks.

Keywords:Fly Ash Brick, Compressive Strength,

Absorption Coefficient, Clay Bricks

I.INTRODUCTION

During the India day by days the growth of development is

increased that requires of electricity generated from the

thermal power plant and this plant gives residue in the form

of Fly Ash in major quantity. The rate of generation of Fly

Ash far exceeds the increasing growth rate of its user. In the

next ten years, the target of 95 % use of Fly Ash likely bring

into existence [1]. If one considers the expectedgeneration

of Fly Ash over the next two decades, the volume projected

is gigantic and its use program will have to be far more

challenging than what is perceived today. In construction

industries clay bricks were used in 180 billion tons of

common burnt clay bricks are consumed annually

approximately 340 billion tons of clay about 5000 acres of

top layer of soil dug out for bricks manufacture, soil

erosion, emission from coal burning or fire woods which

causes deforestation are the serious problems posed by

brick industry. Continuing use of clay bricks in the

construction industry will lead to extensive loss of fertile top

soil [2]. This could be a devastating environmental hazard.

High demand for clay bricks would result in price hike of

clay bricks. To keep the cost of building materials in a

reasonable range, we should opt in for alternative building

materials like fly ash bricks and hollow or solid blocks. The

material required for the fly ash bricks as Fly ash, lime and

gypsum are available in mutual proximity in many regions.

An economical alternative to conventional burnt clay bricks

will be available if these materials can be used to make

bricks and hollow blocks of adequate strength. Lime and

gypsum are usually available either from mineral sources or

may be procured from industrial wastes [4]. High fineness,

low coal content, and rounded particle shape are, in general,

favorable properties for use in cement and concrete. The

amount of cement or lime or lime plus gypsum required to

achieve a certain strength depends on the amount of free

lime available in the fly ash[5].Fly ash does not modify the

hydric properties of the bricks but it does make them lighter.

In fact, all the bricks with fly ash have a lower density. Fly

ash bricks show less damage than conventional bricks when

exposed tosalt crystallization cycles. This improvement is

due to the reduction of the surface area of the bricks, i.e. the

reduction of the volume of the smallest pores, the ones that

cause the most damage to the bricks due to soluble salt

crystallization. The addition of fly ash can enhance the

quality of the brick, although for restoration purposes if too

much fly ash (P10 wt. %) is added, this can spoil the

aesthetic appearance of the buildings being restored,due to

excessive color differences. Bricks with larger amounts of

fly ash could, however, be considered for use in the

construction of new buildings [6].

II.RESEARCH SIGNIFICANCE

Continuing use of clay bricks in the construction industry

will lead to extensive loss of fertile top soil. This could be a

devastating environmental hazard. High demand for clay

bricks would result in price hike of clay bricks. To keep the

cost of building materials in a reasonable range, we should

option for alternative building materials like fly ash bricks

and hollow or solid blocks. Modern Fly ash bricks are

manufactured using high end pre-programmed hydraulic

machines. Bricks from these machines are tested for its

quality and durability and strength.

A.Experimental Procedure:

Clay Bricks: The process of making a brick has not changed

much over the centuries or across geographies. The clay is

mined and stored in the open. This makes the clay soft and

removes unwanted oxides then mixed with water to get the

right consistency for Moulding. Mixing is done manually

with hands and feet. A lumpof the mix is taken, rolled in

sand and slapped into the mould. Initially, moulds were

made of wood of size 22 X 10 X 7.5 mm (8.66 X 3.93 X

2.95 inch), now metal moulds are used. Sand is used so the

brick does not stick to the mould. The mould is emptied

onto the drying area, where the bricks are arranged in a

herringbone pattern todry in the sun. Every two days they

are turned over to facilitate uniform drying and prevent

warping. After two weeks they are ready to be burnt. The

green bricks are arranged in a kiln and insulation is provided

with a mud pack. Fire holes left to ignite the kiln are later

sealed to keep the heat inside. This is maintained for a week.

Firing like other operations also depends on the knowledge

and experience of the brick maker. After the kiln is

disassembled, the bricks are sorted according to color.

Colour is an indication of the level of burning. Over burnt

bricks are used for paving or covering the kiln while slightly

under burnt bricks are used for building inner walls or burnt

once again in the next kiln.

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