167289632 Replacement of Cement by Metakaolin and Flyash

7/23/2019 167289632 Replacement of Cement by Metakaolin and Flyash

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CHAPTER - 1

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CHAPTER 1

INTRODUCTION

The application of concrete in construction is as old as the days of Greek and roman

civilization. But for numerous reasons, the concrete construction industry is not sustainable. It

consumes a lot of virgin materials and the principal raw material of concrete i.e. cement is

responsible for green house gas emissions causing a threat to environment through global

warming. Therefore, the industry has seen various types of concrete in search of a solution to

sustainable development. Infrastructural growth has witnessed many forms of concrete like igh

!trength "oncrete, igh #erformance "oncrete, and !elf "ompacting "oncrete.

The history of cementing material is as old as the history of engineering construction.

!ome kind of cementing materials were used by $gyptians, %omans, and Indians in their ancient

constructions. It is also believed that the early $gyptians mostly used cementing materials,

obtained by burning gypsum. The story of the invention of #ortland cement is, however,

attributed to &oseph 'spdin, a (eeds Builder and brick layer, even though similar procedures had

been adopted by other inventors. &oseph 'spdin took the patent of #ortland cement on )1st

*ctober 1+). The fancy name of #ortland was given owing to the resemblance of this hardenedcement to the natural stone occurring at #ortland in $ngland. In his process 'spdin mi-ed and

ground hard lime stones and finely divided clay into the form of slurry and calcined it in a

furnace similar to a lime kiln till the "*) was e-pelled. The mi-ture so calcined was then ground

to a fine powder.

%oman builders used volcanic tuff found near #ozzuoli village near ount /esuvius in

Italy. This volcanic tuff or ash mostly siliceous in nature thus ac0uired the name #ozzolona.

(ater on, the name #ozzolona was applied to any other material, natural or artificial, having

nearly the same composition as that of volcanic tuff or ash found at #ozzuoli.

The word #ozzolona was derived from #ozzuoli, a town in Italy a few miles from aples.

The materials are of volcanic region containing various fragments of pumice, obsidian, feldspars,

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and 0uartz etc. The name #ozzolona was first applied e-clusively to this material. But the term

has been e-tended later to diatomaceous earth, highly siliceous rocks I and other artificial

materials. Thus, the pozzolanic material is natural or artificial having nearly the same

composition as that of volcanic tuffs or ash found at #ozzuoli.

"oncrete is an artificial material in which the aggregates both fine and coarse are

bounded together by the cement when mi-ed with water. The concrete has become so popular

and indispensible because of its inherent characteristics and advantages either when green or

hardened. The use of reinforcement in concrete has brought a revolution in applications, design

and construction techni0ues. Its great versatility and relative economy in filling wide range of

needs has made it a very competitive building material.

The use of pozzolanic materials in cement concrete paved a solution for

a2 odifying the properties of the concrete

b2 "ontrolling the concrete the production cost

c2 To overcome the scarcity of cement and finally

d2 The economic advantageous disposal of industrial wastes

The most important pozzolanic materials are fly ash, silica fume, and metakaolin whose use

in cement and concrete is thus likely to be a significant achievement in the development of

concrete technology in coming few decades.

1.1 High Strength Concrete & High Performance Concrete

"ompressive strength of concrete is the most important parameter to assess its 0uality.

ormal strength concrete by '"I definition is a concrete that has a cylinder compressive

strength not e-ceeding ) #a, #rasad and &ha. 'll other concretes with strength more than the

specified one are referred as igh !trength "oncretes 3!"2. 4ith the advancements in

technology, the demand of !" increased in the construction industry but then came the new

buzz word 5igh #erformance "oncrete6.

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'ccording to 'itcin 8199:;, #" is nothing but !" as high strength concrete not only

gives high ultimate strength but performs better in many aspects like durability, abrasion

resistance, and sulphate attack etc. '"I defines #" as


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This definition ade0uately addresses the potential for lack of durability of #" concrete

e-cept with massive structural members that may be sub>ect to thermal cracking. In this regard,

an earlier definition proposed by ehta and G>orv819+); stated that the term #" should be

applied to concrete mi-tures possessing the following three characteristicsD high workability,

high strength, and high durability.

1.POZZOLONIC ADMIXTURES IN CONCRETE

#ozzolona is either naturally occurring or available as waste material. They mainly

contain silica, which becomes reactive in the presence of free lime available in "ement when

pozzolanic admi-tures are mi-ed with cement. The reactivity varies depending upon the type of

#ozzolona, its chemical composition and its fineness.

In developing countries like India, pozzolanic materials are mainly available as industrial

waste by@products. Cly ash, silica fume, none dust, blast Curnace slag, rice husk ash etc., are

some of the industrial wastes and eta"em is is a 0uality controlled reactive #ozzolona, made

from purified kaolin which possess pozzolanic properties. $-tensive research work has been

carried out on the use of #ozzolona6s in construction materials.

*ut of the above pozzolanic admi-tures, fly ash can be considered as the one which is if

abundantly available. Cly ash concrete possesses certain desirable and enhanced properties

compared to ordinary plane concrete. etakaolin made from purified kaolin, is not industrial

waste product, can be recommended to be used along with "ement to derive certain enhanced

properties for concrete in special situations.

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1.!O"ER"IE# ON PO$$O%ONAS IN CONCRETE

1. 'ENERA% O"ER"IE# ON PO$$O%ONA(S

The use of pozzolanic materials is as old as that of the art of concrete construction. It was

recognized long time ago, that the suitable #ozzolona used in appropriate amount, modify certain

properties of fresh and hardened mortars and concretes.

In recent years, pozzolanic materials are being used as an addition or partial replacement

for the more e-pensive #ortland cement to improve the properties of the concrete. #ozzolanic

materials are siliceous and aluminous materials which possess little or no cementitious value, but

will, in finely divided from and in the presence of moisture, chemically react with calcium

hydro-ide 3lime2 liberated on hydration at ordinary temperatures to form compounds 3calcium,

silicate, hydrate gel2 possessing cementitious properties. The calcium hydro-ide, otherwise a

water soluble material, is converted into insoluble cementitious materials by the use of

pozzolanic materials.

The action is termed as 5#ozzolanic actionE. The rate of reaction is slow at early age and

pozzolanic action is more pronounced when the admi-ture concrete is 9: days old.

The reaction can be shown as

#ozzolona F "alcium ydro-ide F 4ater " H ! H 3Gel2

This reaction is called pozzolanic reaction. The characteristic feature of pozzolanic

reaction is firstly slow, with the result that heat of hydration and strength development will be

accordingly slow. The reaction involves the consumption of "a 3*2)and not production of "a

3*2). The reduction of "a 3*2)improves the durability of cement paste by making the paste

dense and impervious.

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It has been amply demonstrated that the best #ozzolona in optimum proportions mi-ed with

#ortland cement improves many 0ualities of concrete, such asD

a2 (ower the heat of hydration and thermal shrinkage

b2 Increase the water tightness

c2 %educe the alkali@aggregate reaction

d2 Improve resistance to attack by sulphate soils and sea water

e2 Improve e-tensibility

f2 (ower susceptibility to dissolution and leaching

g2 Improve workability

h2 (ower costs

In addition to these advantages, contrary to the general opinion, good #ozzolona6s will not

unduly increase water re0uirement or drying shrinkage.

#ozzolanic materials can be divided into two groups, namely

1. atural #ozzolona6s

). 'rtificial #ozzolona6s

The natural #ozzolona6s are

a2 "lay and shale6s

b2 *paline shale6s

c2 Jiatomaceous earth

d2 /olcanic tuffs and

e2 #umicities

*n the other hand the artificial #ozzolona6s are

a2 (ow calcium fly ash

b2 igh calcium fly ash

c2 !ilica lime

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d2 !urkhi

e2 etakaolin

f2 %ice usk ash

eta"em is made from purified kaolin. ost of the natural #ozzolona6s re0uire grinding

to a high degree of fineness to make them suitable for use in concrete e-cept #umicities, which

are normally in the finely divided form.

1.'ENERA% O"ER"IE# ON AD)I*TURES

'ccording to %ichard G. ielang, an admi-ture is defined as a material other than water,

aggregate and cement that is added as an ingredient of concrete or mortar either immediately

before or during the process of mi-ing to modify certain desired properties of the normal fresh or

hardened concrete or mortar or the grout.

The most common reason for adding admi-tures are to alter the workability, improve the

rate of gain of strength, increase the strength itself, improve the impermeability and durability

and also to improve the appearance. !ometimes many admi-tures affect more than one property

of concrete. !ometimes they affect the desirable properties adversely. 'n admi-ture should be

employed only after an appropriate evaluation of its effects on the particular concrete under the

conditions in which the concrete is intended to be used. Therefore one must be cautious in the

selection of admi-ture and in predicting the effect of the admi-ture in concrete.

There are wide variety and very large number of admi-tures available in the construction l

market. The admi-tures are classified mainly into 1A groups as follows according to the type of

materials constituting the admi-ture or characteristic effect of the use.

a2 'ir entraining agents

b2 'ccelerators

c2 %etarders

d2 #ozzolona

e2 Gas forming agents

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f2 'ir entraining agents

g2 'lkali aggregate e-pansion inhibitors

h2 Jamp proofing and permeability reducing agents

i2 4orkability agents

>2 Grouting agents

k2 "orrosion inhibiting agents

l2 Bonding agents

m2 "oloring agents

n2 Cungicidal, Germicidal and insect cal agents

o2 iscellaneous agents

1.+ ,% ASH

Cly ash, an artificial #ozzolona, is the un burnt residue resulting from combustion of

pulverized coal or lignite, mechanical or electrostatic separators called hoppers collect it from

flue gases of power plants where powdered coal is used as fuel. This material, once considered as

a by@product finding difficulty to be disposed off has now become a material of considerable

value when used in con>unction with concrete as an admi-ture.

The earliest literature available on the use of Cly 'sh is in 197) which was carried out by

"leveland $lectric Illuminating "ompany and The Jetroit $dison "ompany. owever, the use

of Cly 'sh in concrete was first carried out by Javis and his associates in Lniversity of

"alifornia in 197K. $-tensive research was carried out throughout the world to promote the use

of Cly 'sh in construction, only a few milestones could be achieved till 19: and that too in

developed countries only. 's far as India is concerned, the first ever study on use of fly ash in

concrete was carried out in 19AA by "B%I, %oorkee, in the form of a review of 'merican and

'ustralian research work on Cly ash. (ater, Cly ash was used in small proportions in mass

concreting for dams and other hydraulic structures.

The current fly ash worldwide production is nearly 1+:: million tonnes. Cly ash is

available in large 0uantities in India also. Cor every 1:: 4 of power generation, nearly :.)

million tones of fly ash is being produced. %ecent data show that from more than K: thermal

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power stations, nearly : million tones of fly ash are being produced every year in India. It is

estimated that production of fly ash, by the run of the century, will be 1:: million tones. 'bout

::: tonnes of ash is being produced daily at present in 'ndhra #radesh alone.

!uch vast 0uantities of fly ash are causing pollution hazards affecting the ecological

balance and human habitat environment. The disposal of these huge Cly 'sh 0uantities is

becoming a great problem day by day. anagement of coal ash of this magnitude is a matter of

great concern in the years to come. In view of the above serious considerations on fly ash, lot of

investigation is being carried out to make its use as an alternative building material in

construction, besides finding solution to disposal of fly ash, this would also save enormous

amount of energy and scarce raw materials in the construction industry.

Increased awareness of environmental hazards, steep rise in prices of building materials,

non availability of space to stack the fly ash and other factors have generated interest among the

research community to work on the gainful utilization of fly ash. %esearches all over world have

proved that fly ash is suitable material for material for construction with many beneficial

properties.

It is disappointing fact that only )M of the total generated fly ash is now being utilized in

India, despite the enormous research work on utilization of fly ash in construction industry in the

past half century. Crance is using A+M of its fly ash production while the $uropean countries are

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using l:@):M of their fly ash production. The reason for this situation is, perhaps the lack of

awareness on utility of fly ash at the root level of construction society.

The technology on fly ash utilization has to be intensively taken to the door step of actual

construction for its effective implementation thus increasing the use of fly ash. "onfirmative

e-perimental results on using fly ash as a partial replacement to cement especially in structural

components at different levels in the construction society would definitely improve the use of fly

ash.

1. USE O, ,% ASH IN HI'H STREN'TH CONCRETE

The use of fly ash in high strength concrete has been tried for long and sufficient

literature and data is available on the topic but very little research has been done in India on this

front. oreover, the properties of fly ash available from various sources and even from same

source at different times are not constant. Therefore, the results available on a particular fly ash

in a particular country cannot be fitted in everywhere. ence, there is a scope of studying the

effect of varying percentages of fly ash on various properties of different grades of concrete in

India.

Cly ash is most commonly used as a pozzolona in concrete. #ozzolonas are siliceous or

siliceous and aluminous materials, which in a finely divided form and in presence of water, react

with calcium hydro-ide at ordinary temperatures to produce cementitious compounds. The

spherical shape and particle size distribution of fly ash improves the fluidity of flowable fill,

thereby, reducing the demand of mi-ing water and contributing to long term strength of high

strength concrete with fly ash. The use of fly ash in !" and #" has been studied by various

researchers in past. The use of fly ash in concrete has been encouraged all over the world, 'dams

819++; aik et al 819+9; replaced :M cement by fly ash and achieved an increase in strength of

concrete of )7M and 7+M at )+ days and A days, respectively. %a>u et al. 8199; 1) too tried a

:M replacement of cement by fly ash and achieved a characteristic strength of A #a at )+

days with 4" ratio :.. The benefits of incorporating fly ash in to concrete have been

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demonstrated through e-tensive research and countless highway and bridge construction

pro>ects.

The dosage of fly ash in concrete is generally restricted to 1A@):M by mass of total

cementitious material for commercial purposes. owever, this small percentage is beneficial in

achieving a good workability and for cost economy but it may not improve durability to

considerable e-tent.

!ome of the benefits of fly ash in concrete are

igher ultimate strength

Improved workability

%educed bleeding

%educed heat of hydration

%educed permeability

Increased resistance to sulphate attack

(owered costs

%educed shrinkage

Increased durability

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1./ SI%ICA ,U)E

!ilica fume is a mineral admi-ture made up of very line, solid, glassy spheres and

amorphous solids of silicon dio-ide. It is a by@product obtained during the production of metallic

silicon or Cerrosilicon alloys in electric arc furnaces. The silica content is as high as e-ceeding

9+M as compared to about 7+ to +M in the case of fly ash. Because of e-treme fineness, it is a

very efficient pozzolanic material.

!ilica fume, also referred to as micro silica or condensed silica fume, is another material

that is used as an artificial pozzolanic admi-ture. It is a product resulting from reduction of high

purity 0uartz with coal in an electric arc furnace in the manufacture of silicon or ferrosilicon

alloy. !ilica fume rises as an o-idized vapor. It cools, condenses, and is collected in cloth bags. It

is further processed to remove impurities and to control particle size.

"ondensed silica fume is essentially silicon dio-ide 3more than 9:M2 in non@crystalline

form. !ince it is an airborne material like fly ash, it has spherical shape. It is e-tremely fine with

particle size less than 1 micron and with an average diameter of about :.1 micron, about 1::

times smaller than average cement particles. !ilica fume has specific surface area of about

):,::: m)kg as against )7: @ 7:: m)kg.

!ilica fume is thus found a place to be in the group of pozzolanic admi-tures and made

away for the research community to develop high strength concretes of the order up to A: or

more. The silica fume concretes 3!C"2 are found to posses improved permeability properties.

The sulphate resistance of !C" is also considerably good.

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1.0 )ETAAO%IN

etakaolin is obtained by calcinations of pure or refined kaolin clay at a temperature

between A:N" and +A:N", followed by grinding to achieve a fineness of K:: m)kg to 9::m)kg.

The resulting material has high pozzolanity.

etakaolin is manufactured from pure raw material to strict 0uality standards. It is not a

by@product. *ther pozzolanic materials are currently available, but many are by products, which

are available in chemical composition. They may also contain active components 3such as

sulphur compound, alkalis, carbon, reactive silica2 which can undergo delayed reactions within

the concrete and cause problems over long time periods.

etakaolin is a high 0uality pozzolanic material, which is blended with #ortland cement

in order to improve the durability of concrete and mortars. etakaolin removes chemically

reactive calcium hydro-ide from the hardened cement paste. etakaolin reduces the porosity of

hardened concrete. etakaolin densities and reduces the thickness of the interfacial zone, this

improving the adhesion between the hardened cement paste and particles of sand or aggregate.

ighly reactive metakaolin is made by water processing to remove un@reactive impurities

to make 1::M reactive #ozzolona. !uch a product, white or cream in color, purified, thermally

activated is called igh %eactive etakaolin 3%2. igh reactive metakaolin shows high

pozzolanic reactivity and reduction in "a 3*2)even as early as one day. It is also observed that

the cement paste undergoes distinct densification. The improvement offered by this densification

includes an increase in strength and decrease in permeability. The high reactive metakaolin is

having the potential to compete with silica fume.

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1.2 I)PORTANCE O, )ETAAO%IN

The 0uest for developing high strength and ultra high strength concretes and is special

purpose concretes with certain special characteristics for use under special circumstances is

increasing from time to time. The usual ultimate utilitystrengthdurability parameters of normal

cement concrete needs certain modifications.

The special characteristics of silica fume, viz., super fineness, high silica content and etc.,

gave the scope for enhancing the normal cement concrete which when mi-ed with cement as a

partial replacement. The e-cessive cohesiveness and e-cellent sulphate resistance of

etakaolin mi-ed concrete is of greater importance is !hotcrete applications. etakaolin is

generally more efficient in concrete having higher water@cement ratios.

1.13 STREN'TH PARA)ETERS

Because of very high silica content and super fineness, its reactivity is more, compared to

other pozzolanic admi-tures. 's a result it contributes to strength improvement. Lltra high

strength concrete of the order K: mm) to 1): mm)is now possible for field place able

concrete with metakaolin admi-ture. !uch high strength concrete has increased modulus of

elasticity, lower creep, and drying shrinkage. 'nother strength parameter of etakaolin is its

gain in strength at early ages.

1.11 ENHANCED DURA4IUT

etakaolin renders concrete more impermeable and watertight. The degree of

impermeability of etakaolin concrete is more than fly ash cement concrete. 's a result the

ingress of e-ternal agents into concrete is prevented. 's such it renders "oncrete more durable.

The high silica content makes the etakaolin contents more chemically resistant and pro>ects the

l concrete from the attack of sulphates. ence deterioration of concrete and possible corrosion of

steel reinforcement can be reduced.

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Thus the etakaolin renders concrete more durable. The etakaolin can be

advantageously utilized for preparing concrete mi-es, which are stronger, more durable, and also

economical. The addition of etakaolin does improve the performance of the concrete

substantially. But availability and cost are likely to limit its utilization, at least for the present

only to special concrete suitable for specialized applications.

1.1 APP%ICATIONS

The etakaolin mi-ed concrete is finding place in the following applications from technical

considerations.

a2 In tall and heavy structures where high strength concretes are re0uired

b2 In #!" works where too high strength concretes are essentially re0uired

c2 In concrete works where corrosion problem is more i.e. in coastal areas O marine work

d2 In precast concrete works

e2 In combination with other chemical admi-tures and steel fibers, it is suitable for repair

works

f2 The low permeability and absorption of the etakaolin mi-ed cement concrete as well as

it enhanced resistance to deterioration in a variety of chemically aggressive

environments, found a gainful use in !hotcrete applications in chemical, mining, paper

and pulp industries

g2 In the manufacture of concrete pipes, etakaolin addition has shown to increase the

e-ternal load bearing capacity of the pipes and increased resistance against chemical

attack

h2 "oncrete containing etakaolin is known as to have improved resistance to freezing,

thawing, chloride penetration, and dealer scaling making it useful for road construction

i2 Ciber cement O Cerro cement products, Glass Ciber %einforced concrete, ortars,

stuccos, %epair aterials, #ool #lasters etc.,

Jue to the above reasons etakaolin can be advantageously utilized for preparing concrete

mi-es, which are stronger, more durable. The addition of metakaolin does improve the

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performance of concrete substantially. But availability and cost are likely to limit its utilization,

at least for present, only to special concretes suitable for specialized applications.

1.1! PROPERTIES O, )ETAAO%IN

etakaolin grades of "alcined clays are reactive alumino silicate #ozzolona formed by

calcining very pure hydrous "hina clay. "hemically etakaolin combines calcium silicate and

calcium processed to remove uncreative impurities producing almost 1:: percent reactive

material. The particle size of etakaolin is significantly less than cement particles. I!D A@):::

recommends use of etakaolin as mineral admi-ture.

etakaolin is a thermally structure, ultrafine #ozzolona which replace industrial products

such as silica fumemicro silica. "ommercial use of etakaolin has already several countries

worldwide. etakaolin removes chemically reactive calcium o-ide from the hardened cement

paste. etakaolin reduces the porosity of hardened concrete, etakaolin densities, reduces the

thickness of the interfacial zone, this improving the adhesion between the hardened cement paste

and particles of sand or aggregate.

Blending with #ortland cement etakaolin improves the properties of concrete and cement

products considerably byD

a2 Increasing compressive and fle-ural strength

b2 #roviding resistance to chemical attack

c2 %educing permeability substantially

d2 #reventing 'lkali@!ilica %eaction

e2 %educing efflorescence O !hrinkage

f2 #rotecting corrosion

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1.1 PHSICA% PROPERTIES

'verage particle size, mm 1.A

%esidue 7)A mesh 3M ma-2 :.A

B.$.T. !urface area, m) gm 1A

#ozzolanic %eactivity, mg "a 3*2) gm 1:A:

!pecific Gravity ).A

Bulk Jensity, gm( 7::F or @7:

Brightness +: F or )

#hysical form *ff@white powder

1.1+ CHE)ICA% CO)POSITION 5 #T

!i*)F 'l)*7F Ce)*7 9.++M

"a* :.79M

g* :.:+M

Ti*) 1.7AM

a)* :.AM

P)* :.:M

(i)* il

(*.I :.+M

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1.1PO$$O%ANIC REACTI"IT

etakaolin is a lime@hungry #ozzolona that reacts with free calcium hydro-ide to form

stable, insoluble, strength@adding, cementitious compounds. 4hen etakaolin % 3'!)2

reacts with calcium hydro-ide 3"2, cement hydration by@products, a pozzolanic reaction takes

place whereby new cementitious compounds, 3"Q'!!2 and 3"!2 are formed. These newly

formed compounds will contribute cementitious strength and enhanced durability properties to

the system in place of the otherwise weak and soluble calcium hydro-ide.

"ement ydration #rocess

*#" F ): @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"! F "

#ozzolanic %eaction #rocess

)o

'!) F "@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@")'!+F "!

Lnlike other commercially available pozzolanic materials, etakaolin is a 0uality

controlled manufactured material. It is not a by@product of unrelated industrial process.

etakaolin has been engineered and optimized to contain a minimum of impurities and to react

efficiently with cement6s hydration by@product calcium hydro-ide. Table summarizes the relative

relativities of si- different #ozzolona6s including igh %eactive etakaolin@%.

1.1/ REACTI"IT O, PO$$O%ANIC )ATERIA%S

Table 1.1 @ %eactivity of #ozzolonic aterials

)ateria6 Po77o6anic Reacti8it9 mg Ca :OH;


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1.10TERNAR 4%ENDED CONCRETE :TERNAR CE)ENT SSTE);

It means etakaolin or other cement replacement additives are to be used with *#"

only. That is not strictly true and ternary mi-tures comprise efficient @systems. The primary

incentive of adding limited amount etakaolin Hfor e-ample A percent with Cly@ash cement

mi-es was to ensure high early strength research has however, shown that Ternary mi-tures of

*#", etakaolin and Cly@ash result in synergic action to improve the micro structure and

performance of concrete. 4hen both etakaolin and Cly@ash are used, the resultant enhancement

of strength or pozzolanic activity was greater than super position of contributions of each, for the

respective proportions. !uch synergic effect results from strengthening the weak transition zone

in aggregate cement interface, as well as segmentation and blocking of pores.

Jepending upon the service environment in which it is to operate, the concrete structure

may have to encounter different load and e-posure regimes. In order to satisfy the performance

re0uirements, different ternary compounds re0uired. !uch as cement, fly@ash, metakaolin, silica

fume. Greater varieties are introduced by the corporation of additives like pozzolona, granulated

slag are inert fillers this leads to different specifications of cements in national or international.

1.12 E,,ECTS O, TERNAR 4%ENDIN'

The combination of etakaolin and Cly ash in a Ternary cement system 3i.e., #ortland

cement being the third component2 should result in a number of synergistic effects, some of

which are obvious or intuitive, as followsD

etakaolin compensates for low early strength of concrete with low "a* fly ash.

Cly ash increases long@term strength development of etakaolin concrete.

Cly ash offsets increased water demand of etakaolin.

Cly ash due to presence of spherical particles that easily rollovers one another reducing

inter partial friction 3call bearing effects2 leads to improved workability and reduction in

water demand.

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1.3 ,I4ERS

!teel Cibers reinforce in three dimensions throughout the entire matri-. They restrain

micro@cracking and act as tiny reinforcing bars. The earlier a crack is intercepted and itsE growth

inhibited, the less chance it will develop into a ma>or problem. "ompared to plain or

conventional reinforced concrete the most noticeable differences are improved ductility and post

crack performance. !horter fibers with a high fiber count offer superior first crack strength and

better fatigue endurance.

Ciber reinforced concrete 3C%"2 is concrete containing fibrous material which increases

its structural integrity. It contains short discrete fibers that are uniformly distributed and

randomly oriented. Cibers include steel fibers, glass fibers, synthetic fibers, and natural fibers.

4ithin these different fibers that character of fiber reinforced concrete changes with varying

concretes, fiber materials, geometries, distribution, orientation and densities.

1.1 HISTORICA% PERSPECTI"E

The concept of using fibers as reinforcement is not new. Cibers have been used as

reinforcement since ancient times. istorically, horsehair was used in mortar and straw in mud

bricks. In the early 19::s, asbestos fibers were used in concrete, and in the 19A:s the concept of

composite materials came into being and fiber reinforced concrete was one of the topics of

interest. There was a need to find a replacement for the asbestos used in concrete and other

building materials once the health risks associated with the substance were discovered. By the

19:s, steel, glass 3GC%"2, and synthetic fibers such as polypropylene fibers were used in

concrete, and research into new fiber reinforced concretes continues today.

1. E,,ECT O, ,I4ERS IN CONCRETE

Cibers are usually used in concrete to control cracking due to both plastic shrinkage and

drying shrinkage. They also reduce the permeability of concrete and thus reduce bleeding of

water. !ome types of fibers produce greater impact, abrasion and shatter resistance in concrete.

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The amount of fibers added to a concrete mi- is e-pressed as a percentage of total volume of the

concrete and fibers, termed volume fraction 3/f2. /f typically ranges from :.1 to 7M.

'spect ratio 3ld2 is calculated by dividing fiber length 3l2 by its diameter 3d2. Cibers with

a non@circular cross section use an e0uivalent diameter for the calculation of aspect ratio. If the

modulus of elasticity of the fiber is higher than the matri- 3concrete or mortar binder2, they help

to carry the load by increasing the tensile strength of the material. Increase in the aspect ratio of

the fiber usually segments the fle-ural strength and toughness of the matri-. owever, fibers

which are too long tend to RballR in the mi- and create workability problems.

The orientation factor denotes the efficiency with which randomly oriented fibers can

carry a tensile force in any one direction. The effectiveness of fiber orientation is shown in table

below

Table 1.) H *rientation and $fficiency of Cibers

Orientation = Efficienc9 of fi>er?

1. Lni directional

). *rthogonal

7. %andom 3#lanar2

. %andom 3!patial2

1::

:@A:

7:@:

1A@):

1.! 4ENE,ITS

!teel fibers canD

Improve structural strength

%educe steel reinforcement re0uirements

Improve ductility

%educe crack widths

Improve impact O abrasion resistance

Improve freeze@thaw resistance

Blends of both steel and polymeric fibers are often used in construction pro>ects in order to

combine the benefits of both products? structural improvements provided by steel fibers and the

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resistance to e-plosive spalling and plastic shrinkage improvements provided by polymeric

fibers.

In certain specific circumstances, steel fiber can entirely replace traditional steel

reinforcement bar in reinforced concrete. This is most common in industrial flooring but also in

some other pre casting applications. Typically, these are corroborated with laboratory testing to

confirm performance re0uirements are met.

"are should be taken to ensure that local design code re0uirements are also met which may

impose minimum 0uantities of steel reinforcement within the concrete. There are increasing

numbers of tunneling pro>ects using precast lining segments reinforced only with steel fibers.

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CHAPTER -

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CHAPTER

%ITERATURE RE"IE#

This chapter deals with the review of literature related to studies on Ternary Blended

"oncrete and $ffects and performance of concrete with ternary blends.

Till three@four years ago, hardly anybody in India was aware of the use of metakaolin in

concrete. Juring these four years, the developments that have taken place include increased

awareness of the huge potential of production of metakaolin in the country 3with huge mineral

resource, that is, kaolin availability across the country2, start of indigenous commercial

production and many investigations on the development of concrete mi-es containing

metakaolin.

.1 THE USE O, )ETAAO%IN IN CO)4INATION #ITH ,% ASH

The benefits of using metakaolin or fly ash separately in concrete as partial replacement

for #ortland cement are fairly well@established, especially for fly ash. owever, because the cost

of metakaolin is about @A times the cost of ordinary #ortland cement, thus using metakaolin

alone as a supplementary cementitious material 3!"2 may not be cost effective. *n the other

hand, the slow reaction rate of fly ash can make its use impractical when rapid early strength

development is re0uired. owever, use of these materials in combination H as a ternary blend H

has the potential to overcome the higher cost associated with metakaolin concrete and the slower

strength development associated with fly ash concrete 8;.

. E,,ECTS O, ,% ASH

Cly ash has standards in many countries. ' significant problem is that two ashes, both

meeting a specific standard, can give very different performance in concrete. Therefore, strict

procedures for evaluation and specification of ash for concrete are re0uired. Cly ash usually is

beneficial in providing long@tem strength and impermeability. owever, fly ash has a low rate of

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hydration which means that both short term strength and chloride resistance are typically

detrimentally influenced.

This slow development of properties is critical when the structure in 0uestion will be

e-posed to a chloride environment after )@7 days or less. Cly ash has documented good

performance concerning the resistance to chloride penetration.

't volumes of ): M and up there is a very good effect @after hydration is complete.

(esser volume has less effect. The cause of beneficiation from fly ash is believed to be to a

minor part from better particle size distribution, for the ma>or part from binding of chlorides by

the aluminum in the flyash.

.! E,,ECT O, )ETAAO%IN

etakaolin removes chemically reactive calcium o-ide from the hardened cement paste.

etakaolin reduces the porosity of hardened concrete, etakaolin densities, reduces the

thickness of the interfacial zone, this improving the adhesion between the hardened cement paste

and particles of sand or aggregate.

Blending with #ortland cement etakaolin improves the properties of concrete and cement

products considerably by Increasing compressive and fle-ural strength, providing resistance to

chemical attack and %educing permeability substantially.

. TERNAR 4%ENDIN'

%ecent studies of ternary blends, which contain cement and two supplementary materials

3!"s2, have shown improvements in economy, early and late strength 81;, and durability 8+;

and also decrease the heat of hydration as compared to ordinary concrete or binary blends.

Ternary cementitious blends of #ortland cement, silica fume, and fly ash offered significant

advantages over binary blends and even greater enhancements over plain #ortland cement, as the

silica fume improves the early age performance of concrete, with the fly ash continuously

refining the properties of the hardened concrete as it matured. In addition, the shortfalls of high

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"a* fly ash in terms of controlling '!% resistance could be compensated for by the

incorporation of relatively small 0uantities of other !"s like silica fume.

!uch combinations produced concrete with generally e-cellent properties and offset the

problems associated with using the increased amounts of high "a* fly ash or silica fume

re0uired when these materials are used individually. In terms of durability 3chloride diffusion,

'!% and sulfate resistance2, such blends were vastly superior to plain #ortland cement concrete,

although it was not clear how the two materials


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with mi-ture without metakaolin. 'lso, shrinkage test was carried out on some specimens. The

results show that shrinkage in specimens containing P were almost the same as that in the pure

cement specimens.

ON' CHEE HUAT B13 3)::2 the study focuses on the compressive strength

performance of the blended concrete containing different percentage of metakaolin. The cement

is replaced accordingly with the percentage of A M, 1:M, 1AM, ):M, and 7:M by weight.

"oncrete cubes are tested at the age of 1, 7, K, and )+ days. In addition, the effect of calcination

temperature to the strength performance is included in the study. Cinally, the strength

performance of metakaolin@concrete is compared with the performance of concrete blended with

silica fume and slag.

The results show that the strength development of concrete blended with metakaolin is

enhanced. It was found that 1:M replacement appears to be the optimum replacement where

concrete e-hibits enhanced compressive strength at all ages comparable to the performance of !C

and GGB!.

)OSER RO4ERT D AAPA%AN A)A% R 'ARAS "ICTOR AND

URTIS I)4ER% E B2 The potential for binary and ternary blends of metakaolin with )

differing particle size distributions, and "lass " fly ash to mitigate alkali@silica reactions 3'!%2

with a highly reactive fine aggregate, were evaluated using accelerated mortar bar test 3'BT2

and concrete prism test 3"#T2 methods. Binary blends of metakaolin or "lass " fly ash reduced

e-pansion by AA@9:M and )A@7KM compared to the control, respectively.

4hen incorporating metakaolin with a lower mean particle size, binary blends showed a

greater reduction in e-pansion compared with "lass " fly ash. Ternary blends of metakaolin and

"lass " fly ash resulted in a marginally higher e-pansion than binary blends incorporating the

same amount of metakaolin. "orrelation between 'BT and "#T results was good at high

levels of e-pansion but poor for those compositions producing e-pansions near the acceptable

limits corresponding to increased addition rates of metakaolin andor "lass " fly ash.

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4AI IPIN' 'AI%IUS A%4INAS B+ Jevelopment of a multivariate statistical

model for consistency parameter prediction including slump, compacting factor and vebe time

for concrete incorporating C' and P is described. The models constructed provide an efficient,

0uantitative, and rapid means for obtaining optimal solutions to consistency prediction for

concrete mi-es using #"@C'@P blends as binder.

Based on the e-perimental data, comprehensive regression analysis and significance tests

were performed and the best@fit models for predicting consistency parameters were found.

/alues of consistency were calculated by the proposed models and gave a good agreement with

observed e-perimental data. It indicates that the models are reliable, accurate and can be used in

practice to predict the consistency of #"@C'@P blends.

A..)U%%CB! 3)::K2Jescribed among the many factors that govern the durability

and performance of concrete in service, type of cement receives greater attention. In his paper he

describes the characteristics of cementitious systems re0uired to meet the diverse re0uirements of

strength and durability of concrete and highlights the advantages of part replacement of *#" by

fly ash, granulated slag and silica fume@ either singly or in combination in ternary blends.

E%ICA $E%I I"ANA RADO"ANO"I DRAFAN O$I B/ Investigated the

deterioration of concrete structures due to the presence of sulfate in soils, groundwater and

marine environments is a well@known phenomenon. The use of blended cements incorporating

materials such as natural pozzolona, fly ash, or silica fume have an important role in the long@

term durability of concrete e-posed to sulfate attack.

R. D. NE"ES AND . C. O. ,ERNANDES DE A%)EID B11 conducted an

e-perimental study to investigate the influence of matri- strength, fiber content and diameter on

the compressive behavior of steel fiber reinforced concrete is presented. Two types of matri- and

fibers were tested. "oncrete compressive strengths of 7A and : #a, :.7+ and :.AA mm fiber

diameter, and 7: mm fiber length, were considered. The volume of fiber in the concrete was

varied up to 1.AM. Test results indicated that the addition of fibers to concrete enhances its

toughness and strain at peak stress, but can slightly reduce the Soung6s modulus.

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!imple e-pressions are proposed to estimate the Soung6s modulus and the strain at peak

stress, from the compressive strength results, knowing fiber volume, length, and diameter. 'n

analytical model to predict the stressHstrain relationship for steel fiber concrete in compression is

also proposed. The model results are compared with e-perimental stressHstrain curves.

E%AHI P.A.). 4ASHEER S.".NANUUTTAN G.U.$ HAN B 3)::92

"onducted an e-perimental investigation was carried out to evaluate the mechanical and

durability properties of high performance concretes containing supplementary cementations

materials in both binary and ternary systems.

The mechanical properties were assessed from the compressive strength, whilst the

durability characteristics were investigated in terms of chloride diffusion, electrical resistivity,

air permeability, and water absorption. The test variables included the type and the amount of

supplementary cementitious materials 3silica fume, fly ash, and ground granulated blast@furnace

slag2. 'll the ternary combinations can be considered to have resulted in high performance

concretes with e-cellent durability properties.

RO%AND 4%ES$NSI R.DOU' HOOTON )ICHAE% D.A. THO)AS AN

CHRIS A. RO'ERS B13199+2 Investigated the Jurability of Ternary cementitious systems.

!even concrete mi-tures, including three ternary concrete mi-tures consisting of various

combinations of silica fume, blast@furnace slag, and #ortland cement were studied.

In this paper they describe the pro>ect in detail and presents field observations and

laboratory findings up to ) years. ' comparative summary revealed that the ternary blend

concretes tested have a greater durability performance than the other mi-tures tested.

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.+ SI'NI,ICANCE O, STUD

*nly a few research studies have e-amined the incorporation of metakaolin in ternary

blend systems, resulting in a body of knowledge which is much less complete compared to the

literature available for fly ash, silica fume, and slag ternary blend systems. %eductions in free

drying shrinkage, restrained shrinkage cracking width, and chloride diffusion rate have been

reported when metakaolin is used in combination with silica fume, as compared to concrete

where these !"s have been used alone.

'nother study showed that when metakaolin is combined with fly ash, the effects of

metakaolin and fly ash on the temperature@rise tend to compensate for one another. Cor e-ample,

the temperature@rise for a 1:M etakaolinH1:M fly ash mortar is the same as that of the plain

cement control. Cor water@cured concrete made with #ortland cement, fly ash, and metakaolin,

increasing the metakaolin content enhanced the )+@day compressive strength and reduced

sorptivity to values below that of the control, whereas the sorptivities of fly ash concrete

e-ceeded that of the control.

Thus, it is believed that a combination of metakaolin and fly ash in a ternary cement

system 3i.e., #ortland cement being the third component2 should result in a number of synergistic

effects, some of which may includeD

Cly ash increases long@term strength development of metakaolin concrete.

Cly ash offsets increased water demand of metakaolin.

Cly ash compensates for higher heat release from metakaolin cement.

The relatively low cost of fly ash offsets the increased cost of metakaolin.

etakaolin compensates for low early strength of concrete with fly ash 3binary blend of

cement and fly ash2.

etakaolin reacts with " to produce "@!@, thus potentially improving the behavior of

higher "a* fly ash for reduces the normally high levels of high "a* fly ash re0uired for

'!% prevention

Thus significant improvements in mechanical and durability properties could be achieved

upon replacing some of the cement with metakaolin, and fly ash.

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SCOPE O, PRESENT IN"ESTI'ATION

./ O4ECTI"ES

The principal ob>ective of this research was to build upon the prior research in #hase I,

which e-amined the effect of metakaolin addition rate on compressive and fle-ural strength

development, plastic concrete properties, shrinkage, permeability, and durability to address

issues not previously considered in #hase I and to e-amine with further testing those results from

#hase I which were inconclusive. ' ma>or focus of this continued research is the development

and characterization of metakaolinfly ash ternary@blended concrete.

The specific ob>ectives of the present investigations are as listed below

a2 To conduct study of producing Blended concrete with etakaolin admi-ture

b2 To conduct study of producing Blended concrete with Cly ash admi-ture

c2 To study the effect of partial replacement of cement by etakaolin and Clyash in

different percentages at K and )+ days compressive strength, split tensile strength

modulus of elasticity, and fle-ural strength

d2 !uper plasticizerD "onplast !#@ 7: !uper plasticizer was used as water reducing agent,

mainly to improve the 4orkability

The scope of present investigation is to study and evaluate the effect of replacement of

cement by various percentages of etakaolin 3:, A, 1:, 1A, and ):2 along with fibers 8: to 1; for

water cement ratio :.7) and to produce Ternary Blended "oncrete. "ubes are cured at K and )+

days and tested for compressive strength. !imilarly cylinders and beams of size are tested for

split tensile strength and fle-ural strength.

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.0TEST PRO'RA)

To evaluate the effect of different percentages of only metakaolin 3:, A, 1:, 1A, and ):2

along fibers 3:@12 with a wc ratio of :.7)

To evaluate the effect of different percentages of only flyash 3:, A, 1:, 1A, and ):2 along

fibers 3:@12 with a wc ratio of :.7)

To evaluate the effect of different percentages of metakaolin and flyash 3:, A, 1:, 1A, and

):2 along fibers 3:@12 with a wc ratio of :.7)

In all mi-es the same type of aggregate i.e. crushed granite, river sand, and the same

proportion of the fine aggregate to the total aggregate used.

.2 THE PARA)ETER STUDIES ARE

#ercentage of etakaolin :, A, 1:, 1A, and ):

#ercentage of Clyash :, A, 1:, 1A, and ):

#ercentage of etakaolin O Clyash :@):, A@1A, 1:@1:, 1A@A and ):@:

Cor each mi- 7 cubes and ) cylinders were casted and tested and ) beams of size

1::-1::-A:: were tested.

The test program consisted of conducting compressive test of cubes, split tensile strength

on cylinders and fle-ural strength on beams.

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CHAPTER - !

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CHAPTER - !

E*PERI)ENTA% PRO'RA)

!.1 'ENERA%

'n e-perimental study is conducted on etakaolin mi-ed igh strength grade of

concretes of : mi- with various percentages of etakaolin replacing cement. The inherent

high pozzolanic reactivity of etakaolin adds to the strength factor when mi-ed with cement

concrete partially replacing cement even at higher strengths. $-perimental study is carried out to

investigate the strength variations in concrete. The e-perimental program has been planned and

carried out in three stages.

!tage ID #rocurement of materials and its testing

!tage IID oulding of specimens and curing

!tage IIID Testing of specimens

!. STA'E 1 PROCURE)ENT O, )ATERIA%S AND ITS TESTIN'

ain constituents of the concrete viz., tine 'ggregate, "oarse 'ggregate, cement and

eta"em have been procured from outside. The materials used in the present program are

shown in plate number

!.! CE)ENT

(ocally available *rdinary #ortland "ement of A7 grade of BI%(' Brand confining to I!I

standards has been procured, and the following tests have been carried out according 1AD+11)@

19+9

a2 !pecific gravity of cement

b2 ormal consistency of cement

c2 Initial and final setting time of cement

d2 "ompressive strength of cement

The results of above tests are tabulated in Table below

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!. PHSICA% PROPERTIES O, CE)ENT

Table 7.1 @ #hysical properties of cement

S.No. Pro


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7.K ,% ASH

The fly ash obtained from yderabad Industries, 'ndhra #radesh is used in the present

e-perimental work.

Below Table gives properties of flyash. The chemical composition of flyash is rich in

silica content which react with calcium hydro-ide to form "@!@ gel. This gel is responsible for

the strength mortar or concrete. The fly ash used to the specification of grade 1 flyash.

!.0 PROPERTIES O, ,% ASH :H9Jera>aJ InJ?trie? %tJ A.P;

Table 7.7 @ #roperties of Clyash

S.No Con?titent? Percentage :=;

1 !ilica, !io) :.9

) 'lumina, 'l)*7 71.:1

7 Iron *-ide, Ce)*7 7.99

(ime, "a* :.K

A agnesia, g* 1.A:

!ulphur Trio-ide, !*7 :.+A

K (oss on ignition :.)

+ !urface 'rea m)kg )7

9 Jrying !hrinkage :.:1)

1: Bulk Jensity 1.)A

~ 7K~


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!.2 ,INE A''RE'ATE

The locally available atural river sand conforming to grading zone II of table of I!

7+7@19K: has been used as Cine aggregate.The following tests have been carried out per the procedure given in I! 7+7@19K:3)2

a2 !pecific Gravity

b2 Bulk Jensity

c2 Grading

d2 Cineness odulus of Cine 'ggregate

!.13 PROPERTIES O, ,INE A''RE'ATE

Table 7. @ #roperties of C'

S.No. Pro


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!.11 SIE"E ANA%SIS O, ,INE A''RE'ATE

Table 7.A H !ieve 'nalysis of C.'

S.No. I? Sie8e#eight

RetaineJ

= Of

#eight

Cm6ati8e = Of

#eight

= Of

Pa??ing

1 .KAmm )A ).A: ).A: 9K.A:) ).7mm A A.: +.1: 91.9:

7 1.1+mm 19 1.9: )A.:: KA.::

:: )K+ )K.+: A).+: K.):

A 7:: 7KA 7K.A: 9:.7: 9.K:

1A: +) +.): 9+.A: 1.A:

K KA 1: 1.:: 99.A: :.A:

Cineness odulus U 7.KK Total U 7K.K:

!.1 COARSE A''RE'ATE

achine "rushed granite confining to I! 7+7@19K: 8)7; consisting ): mm ma-imum size

of aggregates have been obtained from the local 0uarry. It has been tested for #hysical and

echanical #roperties such as !pecific Gravity, !ieve 'nalysis, Bulk Jensity, "ushing and

Impact values and the results have been shown in the Table belowD

Table 7. @ #roperties of ".'

S.No. Pro


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A ).7 mm ): :.77 9+.9+ 1.:)

1.1+ mm : : 9+.9+ 1.:)

K :: micron : : 9+.9+ 1.:)

Cineness odulus .7)+ Total U 7:.)+

Table 9

!.1 CRI)PED ,I4ERS

Galvanized "rimped Iron Cibers with :. mm dia and 7) mm in length are used. The

'spect ratio of the fibers is A7.7.

!.1+ #ATER

#otable water has been used in this e-perimental program for mi-ing and curing.

!.1 SUPER P%ASTICI$ER

!uper #lasticizers are new class of generic materials which when added to the concrete

causes increase in the workability. They consist mainly of naphthalene or melamine sulphonates,

usually condensed in the presence of formal dehyde.

!uper plasticizer concrete is a conventional concrete containing a chemical admi-ture of

super plasticizing agent. 's with super plasticizer admi-tures one can take advantage of the

enhanced workability state to make reductions in water cement ratio of super plasticizedconcrete, while maintaining workability of concrete.

Lse of super plasticizer in %" and construction reduces the possibility of deterioration

of concrete for its appearance, density, and strength. *n the other hand, it makes the placing of

concrete more economical by increasing productivity at the construction site.

!.1/ )I* CASE CONSIDERED

In the present investigation grade of concrete : has been considered. The mi- of

concrete is designed by $ntroy and !haklock? subse0uently mi-es were prepared with a partial

replacement of cement by etakaolin at percentages of :, A, 1:, 1A, O ): by weight of cement

for cubes, cylinders, and beams.

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!.10 )I* DESI'N

i- design can be defined as the process of selecting suitable ingredients of concrete and

determining their relative proportions with the ob>ective of producing concrete of certainminimum strength and durability as economically as possible. The design of concrete mi- is not

a simple task on account of widely varying properties of the constituent materials, the condition

that prevail at the work and the condition that are Jemanded for a particular work for which mi-

is designed.

Jesign of concrete mi- re0uires complete knowledge of various properties of the

constituent materials, the complications, in case of changes on these conditions at the site. The

design of concrete mi- needs not only the knowledge of material properties of concrete m plastic

condition? it also needs wider knowledge and e-perience of concerning. $ven then the proportion

of the material of the concrete found out at the laboratory re0uires modifications and

read>ustments to suit the field conditions.

The i- Jesign for this e-periment was designed using the $ntroy and !hacklocks method.

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)I* DESI'N O, )3 'RADE CONCRETE USIN' ENTRO AND SHAC%OCS

)ETHOD

Target ean !trength U fck F tVs

Cck U : F 1.A V .+ U K) mm)

a-imum !ize of "' U ):mm

Jegree of "ontrol U /ery Good

%eference number U 1

3Cig 9.1 pg 1:, Jesign of "oncrete i-es, Prishna %a>u2

4" ratio U :.7) 3Cig. 9.A2

'ggregateBinder ratio U ).A 3Table 9.12

%e0uired proportions by wt of dry materials

" D C' D "' D 4ater

1 )AV).A1:: KAV).A1:: :.7)

1 :.)A 1.+KA :.7)

"7.:A F :.)A").A F 1.+KA").A F :.7)1 U 9+:

" U 1APg

aterials re0uired per m7by weightD

"ement U 1APgC.' U79Pg

".' U 11+APg

4ater U ):1.APg

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!.12 )I*IN' O, CONCRETE

Initially the ingredients of concrete viz., cement, Clyash and etakaolin were mi-ed, to

which the fine aggregate and coarse aggregate were added and thoroughly mi-ed.

4ater was measured e-actly. Then it is applied to the dry mi- and it was thoroughly

mi-ed until a mi-ture of uniform color and consistency were achieved which is then ready for

casting. #rior to casting of specimens, 4orkability is measured in accordance I! 1199@ 19A9 and

is determined by slump test and compaction factor test.

The results have been tabulated in the Table below

i- #roportion for grade of "oncrete : per m7concrete

Table 7.+ H i- #roportion for grade of "oncrete

4ater "ement %atio :.7)

"ement 1A kg

Cine 'ggregate 79 kg

"ourse 'ggregate 11+A kg

4ater ):1.A kg

oteD a-imum size of "oarse 'ggregate isD ): mm

!.3 )OU%DIN' O, SPECI)ENS

'fter the completion of workability tests, the concrete has been placed in the standard

metallic moulds in three layers and has been compacted each time by tamping rod. ow,

vibrating the concrete in the moulds, using vibrator and the surface of the specimens finish

smoothly. 'fter vibration the top surface of the beam specimens based on I! 1:))@19)8+;

code of practice.

!.1 DETAI%S O, TEST SPECI)ENS

a2 "ompressive !trength of concrete

b2 !plit Tensile !trength of concrete

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c2 Cle-ures !trength

!. CO)PRESSI"E STREN'TH O, CONCRETE

Cor each M of etakaolin and flyash, specimens have been moulded. In all cubes of

size 1::mm - 1::mm have been moulded.

!.! SP%IT TENSI%E STREN'TH O, CONCRETE

Cor each M of etakaolin and flyash, specimens have been moulded. In all cylinders of

size 1A:mm dia O 7::mm height have been moulded.

!. ,%E*URA% STREN'TH

Cor each M of etakaolin and flyash, ) specimens have been moulded. In all beams of

size 1::mm - 1::mm - ::mm have been moulded.

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!.+ A'E O, CURIN' CONSIDERED

"oncrete specimens are cured at K days and )+ days for "ompressive !trength and for )+

days for !plit Tensile !trength O Cle-ural !trength.

!. CURIN' PROCEDURE

'fter the casting cubes, cylinders and beams the moulds are kept for air curing for one

day and the specimens were removed from the moulds after ) hours period of moulding of

concrete. arking has been done on the specimens to identify the M etakaolin and flyash. To

maintain the constant moisture on the surface of the specimens, they were placed in water tank

for curing. 'll the specimens have been cured for the desired age.

!./ TESTIN' PROCEDURE

TEST ,OR )EASURIN' #ORA4I%IT

The following tests have been done measure the workability of concrete according to

Indian !tandard 1199W19A98;

!.0 S%U)P TEST

!lump test is a most commonly used method for measuring the consistency of concrete,

which can be employed either in laboratory or at site of work. It is used conveniently as a control

test, and gives an indication of the uniformity of concrete from batch to batch. The slump test is

performed as per standard procedure with standardized apparatus.

Bottom diameter of frustum of cone ):cm

Top diameter of frustum of cone 1:cm

eight of the cone 7:cm

The initial surface of the mould is thoroughly cleaned? the mould is placed on a smooth

horizontal right and non@absorbent surface. The mould is then filled in four layers each

appro-imately one fourth of the height of the mould. $ach layer is tamped twenty five times by

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tamping rod, taking care to distribute the strokes evenly over the cross@section. 'fter the top

layer has been robbed the concrete is struck of 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 refereed 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 RmmR is taken as slump of concrete.

Table 7.9 H etakaolin slump test results

!.o. M of etakaolin !lump 3mm2 "ompaction factor

1 : AA :.9)

) A AA :.+9

7 1: A :.+ 1A : :.+

A ): 7A :.+1

The results of Clyash are tabulated in Table below

Table 7.1: H Clyash slump test results

!.o.M of

Clyash

!lump 3mm2 "ompaction factor

1 : A: :.+

) A A: :.++

7 1: AA :.9:

1A : :.9:

A ): A :.91

~ ~


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!.2 CO)PACTION ,ACTOR TEST

The compaction factor test is more precise and sensitive than the slump test and is

particularly useful for concrete mi-es of low workability. It measures the workability of concrete

in terms of internal energy re0uired to compact the concrete fully.

The apparatus consists of two hoppers, each in shape of frustum of a cone and one

cylinder. The upper hopper is filled with concrete this being placed gently so that this stage no

work is done on the concrete to produce compaction. This is similar than the upper one and is

therefore filled to overflowing and this always contains appro-imately the same amount of

concrete in standard state, this reduces the influence of the personnel and the concrete falls into

the cylinder. $-cess concrete is cut by two floats of slide across the top of the mould and the net

weight of the concrete in the known volume of the cylinder is determined. The results are

tabulated in Table above.

#artially compacted concrete

"C U @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

Cully compacted concrete

!.!3 TESTIN' O, CU4ES O, CO)PRESSI"E STREN'TH"ompression test is done confirming to 1+DA1@19A987;. 'll the concrete specimens are

tested in a ):: tonnes capacity of the compression testing machine. "oncrete cubes of size

1::mm - 1::mm - 1::mm were tested for crushing strength, crushing strength of concrete was

determined by applying load at the constant rate till the specimens failed. The ma-imum load

applied to the specimens has been recorded and diving the failure load bye area of the specimens

were calculated, graphs, bar charts and the results were recorded are shown in the ne-t chapter.

~ K~


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!.!1 TESTIN' O, C%INDERS ,OR SP%IT TENSI%E STREN'TH

This test is conducted in a ):: tonnes capacity of the compression testing machine by

placing the cylindrical specimen of the concrete, so that its a-is is horizontal between the plates

of the testing machine. arrow strips of the packing material i.e., ply wood is places between the

plates and the cylinder, to receive compressive stress. The load was applied uniformly at a

constant, rate until failure by splitting along the vertical diameter takes place. (oad at which the

specimens failed is recorded and the splitting tensile stress is obtained using the formula based

on I!D A+1@19K:8K;.

The following relation is used to find out the split tensile strength of concrete

CtU 3)Vp2 3XVJV(2

4here # U "ompressive load on the cylinder(U (ength of the cylinder

J UJiameter of the cylinder

The results have been tabulated and graphs, bar charts are plotted and discussions are given later.

!.! TESTIN' O, 4EA)S ,OR ,%E*URA% STREN'TH

The element was simply supported on two rollers .Acm dia over the span of A:cm. The

specimen was checked for its alignment longitudinally and ad>usted if necessary. %e0uired

packing was given using steel packing. "are was taken to ensure the two loading points were at

the same level. The loading was applied on the specimen using 1A tonnes pre calibrated proving

ring at regular interval 1::kgs. The load was transmitted to the element through the I section and

)@1 mm dia. Bars spaced at a distance of )A:mm. for each increment of loading the deflection

at the centre of span was recorded using dial gauge. "ontinuous observations were made and the

cracks were identified with the help of magnifying glass. 4ell before the ultimate stage the

deflection meters were removed and the process of load application was continued. 's the load

was increased the cracks were widened and e-tended to top and finally the specimen collapsed in

fle-ure. 't this stage the load was recorded as the ultimate load. Cle-ural strength of tested

specimens, the variation of fle-ural strength with the percentage of etakaolin and flyash is

shown.

~ +~


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CHAPTER

~ 9~


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CHAPTER-

DISCUSSIONS O, RESU%TS.1 'ENERA%

The detailed results presented in the previous "hapter, both in tabular and Graphical

forms indicated variation in the properties of concrete with different M of etakaolin and flyash.

In the following te-t, these variationsdeviations and the performance of etakaolin concrete is

discussed.

. #ORA4I%IT O, )ETAAO%IN IN CONCRETE

In the present e-perimental investigation, strength properties of concrete admi-ture withvarious percentages of etakaolin 3:M to ):M2 have been studied. etakaolin is a very fine,

pozzolanic material 3specific surface area is more than 1:,::: cm)gm2 having high content of

reactive silica. 4hen etakaolin is used high so as to get all the fine particles take active part in

the chemical reaction. This is more important particularly when high percentages of etakaolin

are used in the mi-. In the present investigation a mi- of : with a water@ cement ratio of :.7)

has been used. Cor all the admi-tured concrete mi-es workability has been measured using

slump cone and compacting factor apparatus.

..1 Effect of


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Table .1 H "ube "ompressive strength of etakaolin Blended "oncrete at K days in mm)

= of )etaao6in 3= += 13= 1+= 3=

3= ,i AK.7A :.:A 1.:9 A+.) AK.91

3.+= ,i A+.79 :.KK .9A A9.1K A9.97

3.+3= ,i A.+A .17 7.: ).A :.7)

3./+= ,i A9.A7 A.) A.91 .7 1.))

1.3= ,i A7.AA 1.9: ).7K A9.9 A+.A7

Graph .1

~ A1~


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Table .) H"ube "ompressive strength of etakaolin Blended "oncrete at )+ days in mm)

= of

)etaao6in

3= += 13= 1+= 3=

3= ,i +1.17 +K.K: 91.+9 9:.)9 +9.:K

3.+= ,i +7.9 91.K) 9.1: 9.7) 9:.+K

3.+3= ,i +.A: 9.): 9.1 9A.)+ 9).1

3./+= ,i +K.7: 9A.) 99.K: 9K.:9 9A.99

1.3= ,i +).K 9:.K: 9.7 9).1 9).)

Graph .)

.!#ORA4I%IT O, ,%ASH IN CONCRETE

~ A)~


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In the present e-perimental investigation, strength properties of concrete admi-ture with

various percentages of Clyash 3:M to ):M2 have been studied. Cly ash is finely divided residue

resulting from the combustion of powdered coal and transported by the flue gases and collected

by electrostatic precipitator.igh fineness, low carbon content, good reactivity are the essence of

good fly ash.

!ince fly ash is produced by rapid cooling and solidification of molten ash, a large

portion of components comprising fly ash particles are in amorphous state. The amorphous

characteristics greatly contribute to the pozzolanic reaction between cement and fly ash. *ne of

the important characteristics of fly ash is the spherical form of the particles. This shape of

particle improves the flow ability and reduces the water demand. In the present investigation a

mi- of : with a water@ cement ratio :f :.7) has been used. Cor all the admi-ture concrete

mi-es workability has been measured using slump cone and compacting factor apparatus.

.!.1 Effect of


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= of ,69a?h 3= += 13= 1+= 3=

3= ,i A.+A A:.A) 9.K +.:+ +.K

3.+= ,i AA.+A A).11 A1.K) A:.)+ K.:

3.+3= ,i A.7+ A1.:) A:.A: A1.1K +.+:

3./+= ,i A.9 AA.)A A.AK A7.: A).1

1.3= ,i A1.)) K.A 9.)A K.+: .K7

Graph .7

~ A~


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Table .H "ube "ompressive strength of Cly ash Blended "oncrete at )+ days in mm )

= of ,69a?h 3= += 13= 1+= 3=

3= ,i+1.17 +7.++ +A.1 +.+7 +9.7)

3.+= ,i+7.9 +.+9 +.K7 +K. 9:.A

3.+3= ,i+.A +A.19 +A.+ +A.K +K.9

3./+= ,i+K.7 ++.+ +9.)+ +9.) 91.A+

1.3= ,i+).K +.A+ +.7K +A.K9 ++.7

Graph .

~ AA~


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.#ORA4I%IT O, ,%ASH & )ETAAO%IN TO'ETHER IN CONCRETE

In the present e-perimental investigation, strength properties of concrete admi-ture with

various percentages of Clyash and metakaolin 3:M to ):M2 have been studied. Cly ash is finely

divided residue resulting from the combustion of powdered coal and transported by the flue

gases and collected by electrostatic precipitator. igh fineness, low carbon content, good

reactivity are the essence of good fly ash. The addition of flyash reduced the water demand and

the addition of metakaolin increased the water demand slightly, but, considering the water

cement ratio of :.7), addition of super plasticizer was re0uired to give a good workability for all

the mi-es. The percentage of super plasticizer was kept as :.KAM throughout the e-periment.

..1 Effect of


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Table .A H "ube "ompressive !trength of Ternary Blend at )+ Jays in mm )

= of ,69a?h &

)etaao6in

1

,3=K)3=

,3=K)3=

!

,+=K)1+=

,13=K)13=

+

,1+=K)+=

,3=K)3=

3= ,i+1.17 +9.:K 9).+K 9K.A+ 9.A +9.7)

3.+= ,i+7.9 9:.+K 97.9A 9A.9+ 9). 9:.A

3.+3= ,i+.A 9).1 9A.AA 99.)+ 9.A) +K.9

3./+= ,i+K.7 9A.99 9.1+ 1:1.) 9A.K+ 91.A+

1.3= ,i+).K 9).) +9.9) 97.K +9.) ++.7

Graph .A

~ AK~


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Table . H !plit Tensile strength of etakaolin blended concrete at )+ days in mm)

= of )etaao6in 3= += 13= 1+= 3=

3= ,i +.:) +.A +.KK +.71 +.7

3.+= ,i +.7 9.1A 1:.:A 9.7) 9.9+

3.+3= ,i 9.A +. 9.K) +.+1 +.KA

3./+= ,i 9.A 1:.)+ 11.:A 1:.)7 1:.:+

1.3= ,i +. 9.:9 9.KK +.97 +.+

Graph .

.. Effect of


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Table .K H !plit Tensile strength of Cly 'sh blended concrete at )+ days in mm)

= of ,69a?h 3= += 13= 1+= 3=

3= ,i +.:) +.+ +.KA 9.1) 9.1

3.+= ,i +.7 9.: 9.77 9.1 9.1

3.+3= ,i 9.A +.+K +. +.9) 9.A)3./+= ,i 9.A 9.7 9.9 9.++ 1:.:

1.3= ,i +. +.A+ +.K) +.+ 9.1

Graph .K

..! Effect of


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Table .+H!plit Tensile strength of Cly 'sh F etakaolin blended concrete at )+ days in mm)

1

3=,K3=)

3= ,K3=)

!

+= ,K1+=)

13= ,K13=)

+

1+= ,K+=)

3=,K 3=)

3= ,i +.:) +.7 +.K7 1:.71 9. 9.11

3.+= ,i+.7 9.9+ 9. 1:.K 1:.1 9.1

3.+3= ,i9.A 1:.:+ +.+ 1:.) 9.AA 1:.:

3./+= ,i9.A 9.1A 1:.71 11.)1 1:.K) 9.A)

1.3= ,i +. +.+ +.A 9.+ 9.+ 9.1

Graph .+

.. Effect of


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Table .9 H )+ days Cle-ural strength of Clyash and etakaolin blended "oncrete in mm)

0%

F+0% M

0%

F+20%M

5%

F+15%M

10%F+10

%M

15%

F+5%M

20%F+0

%M

3= ,i 6.9 7.34 7.22 8.01 7.14 7.02

3.+= ,i7.93 8.74 8.3 9.01 8.59 8.07

3.+3= ,i9.31 9.9 9.74 10.34 9.63 9.41

3./+= ,i10.7 11.19 11.62 12.04 11.49 11.3

1.3= ,i 10.35 11.01 11.26 11.87 10.71 10.53

'ra


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CHAPTER - +

~ )~


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CHAPTER - +

SU))AR O, CONC%USIONS

The following conclusions have been arrived from the studyD

12 etakaolin is an effective pozzolona and results in enhanced early strength and ultimate

strength of concrete.

)2 The compressive strength of young concrete, i.e., K days is improved by blending the

*#" with 1:M of metakaolin by weight.

72 The 1:M replacement with metakaolin is the most optimum replacement, enhancing the

concrete6s compressive strength at all ages.

2 The )+@days compressive strength of concrete was improved by partial replacements of

*#" by metakaolin in the range up to 1:M by weight, and was at the ):M level still

maintained. The highest )+@days strength improvement of concrete can be e-pected at

partial replacements in the 1:@1AM range.

A2 The combined use of metakaolin and a super plasticizer allowed increasing the

aforementioned partial replacement levels, i.e. to ):M in the case of maintaining strength.

2 Ternary blending by etakaolin in combination with Cly 'sh was found leading to

further technical improvements to concrete strength. $specially, blended concrete

mi-tures with etakaolin Cly 'sh @ratio to A:A: by weight revealed higher efficiency

for improving strength at older ages.

K2 'ddition of flyash results in economy of the mi- because of low cost of fly ash.

+2 'ddition of fibers to all the mi-es clearly indicate improvements in all the properties such

as compressive strength, split tensile strength, and most importantly increased fle-ural

strength, this property is very useful in arresting the cracks to a large e-tent.

~ 7~


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Sco


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RE,ERENCES

1. 'ntiohos, !.? aganari, P.? and Tsimas, !.,


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(aboratory and *utdoor $-posure !ite !tudies=. '"I materials >ournals !eptember@

*ctober )::).

%IST O, RE,,ERED INDIAN STANDARD :I.S; CODE 4OOS

1. I.!. 1))9@19+9 !pecifications for A7 grade ordinary #ortland cement.

). I.!. 7+1)@19+1 I! !pecification for flyash for use as puzzolona O addl material

7. I.!. 7+7@19K: !pecification for "oarse and Cine 'ggregate from

atural sources for concrete.

. I.!. A@)::: Indian !tandard #lain %einforced "oncrete@ code of

#ractice.

A. I.!.1:))@19+) %ecommended Guide (ines Cor "oncrete i- Jesign.

%IST O, TE*T 4OOS RE,,ERED

1. %afat !iddi0ue,

7. .!. !hetty

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167289632 Replacement of Cement by Metakaolin and Flyash

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