Flexural Behavior of Fibrous Reinforced Cement Concrete Blended With Fly

International Journal of Research and Innovation (IJRI) 

1401-1402 


Flexural Behavior of Fibrous Reinforced Cement Concrete Blended With Fly 

Ash and Metakaoline 

C.Dheeraj 1 , K. Mythili 2 , B.L.P. Swami 3 

1.Research Scholar, Department of Civil Engineering,At Aurora S Scientific And Technological And Research Academy, Hyderbad - , 

India. 

2.M.Tech(Structural Engineering),Associate Proffesor At Aurora S Scientific And Technological And Research Academy,Bandlaguda, 

Hyderbad - ,India. 

3.Professor and Co-ordinator,Research and Consultancy, VCE,Hyderabad,India 

Abstract 

Research for high strength and better performance characteristics of concrete are leading the researchers for developing 

better structural concrete and new structural application techniques.New types of concrete have come in application 

in construction by using supplementary cementitious materials like fly ash, silica fume metakaoline, nanosilica and 

other materials using various reinforcing materials like different type of fibers for achieving better performance for the 

composite compared to the normal concrete.In the present experimental investigation, a mix design for high strength 

concrete of M80 is tried using triple blending technique with ternary blend of metakaoline and fly ash as partial replacement 

by weight of cement at various blended percentages ranging between 10%-40% with steel fibers having aspect ratio 

of 50. The various percentages of steel fibers to be tried are 0%, 0.5% and 1% by volume of concrete. The workability is 

measured for its consistency using compaction factor method.The project aims at finding the optimum replacement of 

cement by fly ash and metakaoline from which maximum benefit in various strengths and workability of the mix can be 

obtained. The results of fiber reinforced specimens with various percentages of ternary blend are compared with control 

specimens to study the behaviour of FRC properties with various percentages of the blends as partial replacement by 

weight of cement. Sufficient number of cubes and beams will be cast. The case specimens will be tested for the change 

in compressive and flexural strengths at 7 & 28 days for M80 concrete.It is expected that the results of present investigation 

would help to arrive at the optimum percentages of the admixtures and fibre reinforcement to achieve optimum 

strength properties of the composite. 

*Corresponding Author: 

C.Dheeraj , 

Research Scholar, Department of Civil Engineering,At Aurora S 

Scientific And Technological And Research Academy, Bandlaguda, 

Hyderbad - 500005, India. 

Published: December 17, 2014 

Review Type: peer reviewed 

Volume: I, Issue : III 

Citation: C.Dheeraj , ,Research Scholar (2014) Flexural Behavior 

of Fibrous Reinforced Cement Concrete Blended 

With Fly Ash and Metakaoline 

INTRODUCTION 

Concrete Composite 

Concrete is the key material used in various types 

of construction, from the flooring of a hut to a multi 

storied high rise structure from pathway to an airport 

runway, from an underground tunnel and deep 

sea platform to high-rise chimneys and TV towers. 

In the last millennium concrete has demanding requirements 

both in terms of technical performance 

and economy while greatly varying from architectural 

masterpieces to the simplest of utilities. It is 

the most widely used construction materials. It is 

difficult to point out another material of construction 

which is as versatile as concrete. 

Concrete is one of the versatile heterogeneous materials, 

civil engineering has ever known. With the 

advent of concrete civil engineering has touched 

highest peak of technology. Concrete is a material 

with which any shape can be cast and with equal 

strength or rather more strength than the conventional 

building stones. It is the material of choice 

where strength, performance, durability, impermeability, 

fire resistance and abrasion resistance are 

required. 

Cement concrete is one of the seemingly simple 

but actually complex materials. The properties of 

concrete mainly depend on the constituents used 

in concrete making. The main important materials 

used in making concrete are cement, sand, crushed 

stone and water. Even through the manufacturer 

guarantees the quality of cement it is difficult to produce 

a fault proof concrete. It is because of the fact 

that the building material is concrete and not only 

cement. The properties of sand, crushed stone and 

water, if not used as specified, cause considerable 

trouble in concrete. In addition to these, workmanship, 

quality control and methods of placing also 

play the leading role on the properties of concrete. 

Concrete is that pourable mix of cement, water, 

sand, and gravel that hardens into a super-strong 

building material. It has good compressive & flexural 

strengths and durable properties among others. 

Generally people use the words cement & concrete 

as if they were the same, but they’re not. Concrete 

has cement in it, but also includes other materials, 

were cement is what binds concrete together. 

In the last millennium concrete has demanding requirement’s 

both in terms of technical performance 

and economy while greatly varying from architectural 

masterpieces to the simplest of utilities. It’s is 

mouldable, adaptable and relatively fire resistant. 

The fact that it is an engineered material which satisfy 

almost any reasonable set of performance specifications, 

more than any other material currently 

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available has made it immensely popular construction 

material. In fact every year more than 1m 3 of 

concrete is produced per person (more than 10 billion 

tonnes) worldwide. 

Strength (load bearing capacity) and durability (its 

resistance to deteriorating agencies) of concrete 

structures are the most important parameters to 

be considered while discussing concrete. The deteriorating 

agencies may be chemical – sulphates, 

chlorides, CO 2 

, acids etc. or mechanical causes 

like abrasion, impact, temperature, etc. The steps 

to ensure durable and strong concrete encompass 

structural design and detailing, mix proportion and 

workmanship, adequate quality control at the site 

and choice of appropriate ingredients of concrete. 

Type of cement is one such factor. In this paper, 

the significance and effect of the type of cement on 

strength and durability of its corresponding concrete 

is focussed on. 

Depending upon the service environment in which 

it is to operate, a concrete structure may have to 

encounter different load and exposure regimes. In 

order to satisfy the performance requirements, cements 

of different strength and durability characteristics 

will be required. 

The main properties of concrete mainly depend on 

the constituents used in concrete making. The main 

important material used in making concrete are cement, 

sand, crushed stone and water. Even though 

the manufacturer guarantees the quality of cement 

it is difficult to produce a fault proof concrete. It is 

because of the fact that the building material is concrete 

and not only cement. The properties of sand, 

crushed stone and water, if not used as specified, 

cause considerable trouble in concrete. In addition 

to these, workmanship, quality control and methods 

of placing also plays the leading role on the 

properties of concrete. 

Compressive strength of concrete comes primarily 

from the hydration of alite and belite in Portland cement 

to form C-S-H. Alite hydrates rapidly to form 

C-S-H and is responsible for early strength gain; 

belite has a slower hydration rate and is responsible 

for the long term strength improvements. 

Alite: 

2Ca 3 

Sio 5 

+6H 2 

O→3CaO.2Sio 2 

.3H 2 

0+ 3Ca(OH) 2 

Belite: 2C 2 

S + 4H 2 

O = C3S 2 

H 3 

+ CH 

When alite and belite hydrate they produce a byproduct, 

calcium hydroxide (CH), which crystallizes 

around the aggregate to create a weak zone 

called the interfacial transition zone (ITZ). The ITZ is 

where concrete paste has a higher porosity and lower 

strength than the surrounding paste and allows 

the greatest penetration of harmful contaminants. 

High Strength Concrete 

High strength concrete is used extensively throughout 

the world like in the oil, gas, nuclear and power 

industries are among the major uses. The application 

of such concrete is increasing day by day due to 

their superior structural performance, environmental 

friendliness and energy conserving implications. 

Apart from the usual risk of fire, these concrete are 

exposed to high temperatures and pressures for 

considerable periods of times in the above mentioned 

industries. 

High strength concrete (HSC) is a relatively new construction 

material. Technology for producing high 

strength concrete has sufficiently advanced that 

concrete with compressive strength greater than 

40MPa are commercially available and strength 

much higher than that can be produced in laboratories. 

High strength concrete offers significantly 

better structural engineering properties, such as 

higher compressive and tensile strengths, higher 

stiffness, better durability, when compared to the 

conventional normal strength concrete (NSC). 

High-strength concrete is specified where reduced 

weight is important or where architectural considerations 

call for small support elements. By carrying 

loads more efficiently than normal-strength 

concrete, high-strength concrete also reduces total 

amount of material placed and lower the overall cost 

of the structure. High-strength concrete columns 

can hold more weight and therefore be made slimmer 

than regular strength concrete columns, which 

allows for more useable space, especially in lower 

floors of buildings. High strength concrete are also 

used in other engineering structures like bridges. 

From the general principles behind the design of 

high-strength concrete mixtures, it is apparent 

that high strengths are made possible by reducing 

porosity, inhomogeneity, and micro cracks in 

the hydrated cement paste and the transition zone. 

The utilization of fine pozzolanic material in highstrength 

concrete leads to a reduction of size of the 

crystalline compounds, particularly, calcium hydroxide. 

Consequently, there is a reduction of the 

thickness of the interfacial transition zone in highstrength 

concrete. The densification of the interfacial 

transition zone allows for efficient load transfer 

between the cement mortar and the coarse aggregate, 

contributing to the strength of the concrete. 

For very high-strength concrete where the matrix is 

extremely dense, a week aggregate may become the 

weak link in concrete strength. 

Concrete of high strength entered the field of construction 

of high raised buildings and long span 

bridges. In India, there are cases of using high 

strength concrete for prestressed concrete bridges. 

The higher strength concrete could be achieved by 

using one of the following methods or a combination 

some or many of the following: 

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• Higher cement content 

• Reducing water cement ratio 

• Better workability and hence better compaction 

The utilization of fine pozzolanic materials in highstrength 

concrete leads to a reduction of the size 

of the crystalline compounds, particularly, calcium 

hydroxide. Consequently, there is a reduction of the 

thickness of the interfacial transition zone allows for 

efficient load transfer between the cement mortar 

and coarse aggregate, contributing to the strength 

of the concrete. For very high-strength concrete 

where the matrix is extremely dense, a weak aggregate 

may become the weak link in concrete strength. 

The requirement of high strength concrete requires 

mixtures, which could be in the range of 400kg plus 

per m3. The hunger for the higher strength leads 

to other material to achive the desired results thus 

emerged the contribution of cementitious material 

for strength of concrete. Addition of pozzolanic 

admixture like the pozzulanic fly ash (PFA) or condensed 

silica fume (CSF) which helps in the formation 

of secondary C-S-H gel there by improvement of 

strength. The addition of pozzolanic admixture like 

fly ash used as admixture will reduce the strength 

gain for the first 3 to 7 days of concrete will show 

gain beyond 7 days and give a higher strength on 

long term. With the addition of highly reactive pozzolanic 

admixtures like the silica fume will start 

contributing in about 3 days. 

Applications of mineral admixtures such as metakaolin, 

silica fume and ground granulated blast 

furnace slag in concrete are effective easy to future 

increase the strength and make durable for high 

strength concrete. The addition of admixtures to 

the concrete mixture increases the strength by pozzolanic 

action and filling in the small voids and that 

are created between cement particles. 

Metakaolin is the pozzolanic material which is 

mainly derived from a clay mineral “kaolinite”. Since 

it is calcined at higher temperatures it is named as 

“Metakaolin”. A further advantage of pozzolan mortars 

is their lower environmental impact. When 

compared to cement mortars, due to lower energy 

consumption during production and CO 2 

absorption 

by carbonation. The addition of metakaolin to 

mortars and concrete also has a positive effect in 

terms of durability. Calcium hydroxide accounts 

for up to 25% of the hydrated Portland cement, and 

calcium hydroxide does not contribute to the concrete’s 

strength or durability. Metakaolin combines 

with the calcium hydroxide to produce additional 

cementing compounds, the material responsible for 

holding concrete together. Less calcium hydroxide 

and more cementing compounds means stronger 

concrete.Metakaolin, because it is very fine and 

highly reactive, gives fresh concrete a creamy, nonsticky 

texture that makes finishing easier. 

Blended Cements 

Blended cements are defined as hydraulic cements 

"consisting essentially of an intimate and uniform 

blend" of a number of different constituent materials. 

They are produced by "inter grinding Portland 

cement clinker with the other materials or by blending 

Portland cement with the other materials or a 

combination of inter grinding and blending." 

It is a fact that their use save energy and conserve 

natural resources but their technical benefits are 

the strongest. They affect the progress of hydration, 

reduce the water demand and improve workability. 

The concrete containing GGBFS, on vibration 

becomes ‘mobile’ and compacts well. Silica fumes 

greatly reduces, or even eliminates bleeding, the 

particles of Pozzolanic Fly Ash (PFA) are spherical 

and thus improves the workability. Their inclusion 

has the physical effect of modifying the flocculation 

of cement, with a resulting reduction in the water 

demand. The pore size in concrete is smaller. The 

fine particles ‘fit in’ between cement particles, thereby 

reducing permeability. 

Use of Fibers in Concrete 

Fiber Rein forced Concrete is a concrete composed 

of normal setting hydraulic cements, fine or fine 

and coarse aggregates and discontinuous discrete 

fiber with different proportions, different length and 

different gauges as parameters. 

Fibers help make the concrete stronger and more 

resistant to temperature extremes. The Steel fiberreinforced 

concrete is basically a cheaper and easier 

to use form of rebar reinforced concrete. Rebar reinforced 

concrete uses steel bars that are laid within 

the liquid cement, which requires a great deal 

of preparation work but make for a much stronger 

concrete. Steel fiber-reinforced concrete uses thin 

steel wires mixed in with the cement. This imparts 

the concrete with greater structural strength, reduces 

cracking and helps protect against extreme 

cold. Steel fiber is often used in conjunction with 

rebar or one of the other fiber types. 

Steel fibers: 

• Improved structural strength 

• Reduced steel reinforcement requirements 

• Improved ductility 

• Reduced crack widths and control of crack widths 

thus improving durability 

• Improved impact & abrasion resistance 

• Improved freeze-thaw resistance 

When the loads imposed on concrete approach that 

for failure, cracks will propagate, sometimes rapidly, 

fibers in concrete provide a means of arresting 

the crack growth. Reinforcing steel bars in concrete 

have, the same beneficial effect because they act as 

long continuous fibers. Short discontinuous fibers 

have the advantage however of being uniform. If the 

modulus of elasticity of the concrete or mortar binder, 

the fibers help to carry the load, thereby increasing 

the tensile strength of the material. Increases 

96


in the length, diameter ratio of the fibers usually 

augment the flexural strength and toughness of the 

concrete. 

Blends of both steel and polymeric fibers are often 

used in construction projects in order to combine 

the benefits of both products; structural improvements 

provided by steel fibers and the resistance 

to explosive 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 precasting 

applications. Typically, these are corroborated with 

laboratory testing to confirm performance requirements 

are met. Care should be taken to ensure that 

local design code requirements are also met which 

may impose minimum quantities of steel reinforcement 

within the concrete. There are increasing 

numbers of tunnelling projects using precast lining 

segments reinforced only with steel fibers. 

The values of this ratio are usually restricted to between 

100 and 200 sincefibres which are too long 

tend to “ball” in the mix and create workability 

problems. 

As a rule, fibres are generally randomly distributed 

in the concrete; however, processing the concrete 

so that the fibres become aligned in the direction of 

applied stress will result in even greater tensile or 

flexural strengths. 

Advantages of Triple Blending 

The proper us of metakaol in can result in increased 

concrete strength (particularlyearlystrength),improv 

edchlorideandsulphateresistance, reduced efflorescence 

an improveddurability.Usedat5-15% replacement 

ofcement by weight,metakaol in will contribute 

to: increased strength, reduced permeability,greater 

durability and effective control of efflorescence and 

degradations caused by alkali-silica reaction in concrete.In 

addition ,the brighter colour imparted to 

the concrete by metakaolin could improve the night 

driving visibility if metakaolin concrete were used 

in highway and bridge construction and would improve 

the appearance of exposed concrete. 

Main influence of fly ash is on water demand and 

workability. For a constant workability, reduction 

in water demand due to flyash is usually between 5 

to 15 percent by comparison with a Portland cement 

only.A concrete mix containing fly ash is cohesive 

and has a reduced blending capacity. 

Together with flyash and metakaolin as a replacement 

to cement, impart advantages of both flyash 

and metakaolin. The advantages include durability, 

better workability, and reduced heat of hydration. 

One of the main advantages is that the strength reduction 

due to flyash is compensated by addition of 

metakaolin, hence making the mix economical as 

well as of high strength. 

Aim of the Present Project and Details Of The 

Present Study 

The aim of our project is to study the compressive 

strength of high strength mix of M70 grade, with a 

partial replacement of cement with metakaolin and 

flyash. Our project includes the concept of triple 

blending of cement with metakaolin and flyash, this 

triple blend cements exploit the beneficial characteristics 

of both pozzolanic materials in producing a 

better concrete. 

Literature Review 

In order to fulfill the aims and objectives of the present 

study following literature have been reviewed. 

Notable Previous Research 

A number of reports have demonstrated that concretes 

containing combinations of flyash and metakaolin 

with Portland cement are superior in certain 

respects to concretes containing Portland cement. 

The type and source of the cement,characteristics 

and amounts of flyash and metakaolin affected the 

results. 

Current Use of Metakaolin in Concrete Technology 

Metakaolin can be used to replace or add to OPC or 

can be combined with other pozzolans. The proper 

use of metakaolin can result in increased concrete 

strength (particularly early strength), improved 

chloride andsulphateresistance, reduced efflorescence 

an improved durability. Metakaolin,derived 

from purified kaolin clay, is a white, amorphous, 

alumino-silicate which reacts aggressively with calcium 

hydroxide to form compounds with cementitious 

value. Used at 5-15% replacement of cement 

by weight, metakaolin will contribute to: increased 

strength, reduced permeability, greater durability 

and effective control of efflorescence and degradations 

caused by alkali-silica reaction in concrete. In 

addition , the brighter colour imparted to the concrete 

by metakaolin could improve the night driving 

visibility if metakaolin concrete were used in highway 

and bridge construction and would improve 

the appearance of exposed concrete. 

Uses Of Metakaolin 

• High performance, high strength and light weight 

concrete. 

• Precast concrete for architectural, civil, industrial 

and structural. 

• Fibrecement and ferrocement products, glass fiber 

reinforced concrete. 

• Mortars,stuccos, repair material, pool plasters. 

• Manufactured repetitive concrete products. 

• Increased compressive and flexural strengths. 

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• Reduced permeability and efflorescence. 

• Increased resistance to chemical attack and prevention 

of alkali silica reaction 

• Reduced shrinkage. 

• Improved finishability, colour and appearance. 

Pozzolanic Substitution 

Substituting metakaolin for silica fume in existing 

formulations will: 

• Maintain or increase compressive strength at early 

age (1-28 days) 

• Maintain long term compressive strength development 

(>28days) 

• Disperse more easily in the mixer with less dust 

• Not darken the color of the paste or mortar and 

• Reduce superplasticizer demand for the target 

slump. 

Metakaolin is compatible with chemical admixtures, 

as well as with other pozzolansand supplementary 

cementing materials, i.e. flyash, ground granulated 

blast furnace slag. 

Alkali Silica Reaction Problem 

Quality concrete is a carefully selected composition 

of materials which, when properly manufactured, 

proportioned, mixed, placed, consolidated, finished 

and cured will have sufficient strength and durability 

in accordance with the desired application. 

Alkali silica reaction can be explained as the situation 

where cement alkalis reactwith certain forms 

of silica in the aggregate component of a concrete, 

forming an alkali-silica gel at the aggregates surface. 

This formation, often referred to as ”reaction rim” 

has a very strong affinity for water, and thus has 

a tendency to swell. These expanding compounds 

can cause internal pressures sufficiently strong to 

cause cracking of the paste matrix, which can then 

result in a compromisedconcrete with an open door 

to an increasing rate of deterioration. 

The Metakaolin Solution 

When a pure form of metakaolin is employed as a 

pozzolanic mineral admixture at 10-15% weight of 

cement, the calcium hydroxide level can be reduced 

sufficiently to render any gels that are formed as 

non –expansive. The protection is further enhanced 

in view of themetakaolin addition’s effect on overall 

reduced concrete permeability and in a slight reduction 

in the alkalinity of the pore solution. 

Efflorescence 

The phenomenon commonly known as efflorescence, 

occurs when calcium hydroxide a soluble reaction 

by-product of the hydration process of ordinary 

Portland cement is carried to the surface of cementbased 

products by migrating water. Exposed to the 

atmosphere, calcium hydroxide reacts with carbon 

dioxide to form calciumcarbonate deposits which 

remain apparent as unsightly, whitish stains. 

Two forms of efflorescence have been identified- primary 

and secondary. They are distinguished by the 

point in time at which they occur in relation to the 

curing process. Primary efflorescence occurs during 

the curing process. Excess water in the matrix 

bleeds to the surface where it eventually evaporates, 

leaving behind deposits of calcium hydroxide 

crystals(Ca(OH) 2) 

which,when exposed to the carbon 

dioxide(CO 2 

) in the air, form calcium carbonate 

(CaCO 3 

) in the surface pores. 

Secondary efflorescence occurs in the cured concretes 

and composites, which are in contact with 

moisture or are subjected to cycles of re-wetting 

and drying. Moisture penetrates in to and leaches 

from the matrix dissolving soluble calcium hydroxide 

Ca(OH) 2 

that remains as a normal byproduct of 

Portland cement hydration. Upon subsequent drying 

the water with the lime in solution can migrate 

to the surface where upon evaporation, leaves deposits 

of calcium hydroxide Ca(OH) 2 

and subsequently, 

calcium carbonate CaCO 3 

. 

Metakaolin Solution For Efflorescence 

• Eliminate free lime from the system through rapid 

pozzolanic reaction. 

• Increase the density and reduce the porosity and 

permeability of the paste system. 

• Reduce the cement content with pozzolan substitution 

5-15% (the dilution effect). 

Pozzolanic Reactivity 

Metakaolin is a lime hungry pozzolan that reacts 

with free calcium hydroxide to form stable, insoluble, 

strength-adding, cementitious compounds. 

When metakaolin reacts with calcium hydroxide 

(CH) a cement hydration by product, a pozzolanic 

reaction takes place where by new cementitious 

compounds (C 2 

ASH 8 

) and (CSH), 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 hydroxide. 

Metakaolin has been engineered and optimized to 

contain a minimum of impurities and to react efficiently 

with cement’s hydration by-product calcium 

hydroxide. Primary efflorescence can be reduced by 

using metakaolin at 5-15% replacement of cement 

by weight. The use of highly reactive metakaolin 

works to the root of the efflorescence problem by 

eliminating the calcium hydroxide from the system. 

Once fully cured an optimized highly reactive metakaolin 

formulated product cannot exhibit secondary 

efflorescence as virtually all of the available free 

lime has been chemically combined by pozzolan. 

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Reduced Permeability 

Concrete’s porosity, pore interconnectivity and 

overall permeability to fluids have direct influence 

on the concrete’s ultimate durability and useful service 

life. Where quality concrete’s mortars and other 

cement-based products are produced with careful 

control of materials and water to cement ratios, performance 

can be significantly influenced by the addition 

of highly reactive pozzolans. 

The addition of metakaolin to these materials at a5- 

15% replacement b weight of cement will contribute 

to a more compact arrangement of cementitious 

products where increased paste densities, mechanical 

interlock and paste-aggregate bond are the result. 

In addition, the pozzolanic reaction, as described 

above, has a direct and significant influence on the 

materials service permeability. 

As soluble hydration byproducts in a non-pozzolan 

enriched concrete are leached out by migrating 

moisture, they leave behind opened and more interconnected 

pore systems which will set the stage 

for an increased risk and rate of efflorescence discoloration, 

fading and staining. By chemically combining 

with calcium hydroxide, the pore system is 

rendered much more stable. 

Cement Replacement the Dilution Effect 

Metakaolin has the potential to produce high 

strengths in cement based products at 5-155 replacement 

by weight of cement. As such, it is common 

to see increases in concrete or mortar compressive 

strengths (>20%) such that a further 

cement reduction beyond pound for pound cement 

replacement can be taken if strength gains of this 

degree are not required or beneficial. It is possible 

for metakaolin to replace cement by weight at 1:2 to 

1:3,this would, of course, require trial mixes with 

specific materials to confirm the exact formula. 

Metakaolin Features 

• Rapid reaction. The potential to react with more 

than its own weight equivalent in calcium hydroxide. 

• A minimum of impurities 

• Stable to enhanced early strength performance 

(


different cements effect accordingly. 

Temperature: Development of hydroxyl concentration 

appears to be much slower at 20 o C . At 40 o C the 

pH reaches a high value within one day of hydration 

so that the reaction of fly ash can start from first 

day. Temperature also affects the reactivity of fly 

ash itself. That means at a higher temperature the 

reaction will be initiated at lower alkalinity. 

Water cement ratio: There is strong relation between 

fly ash activity and water/cement ratio. Higher 

the W/C ratio, lower the alkalinity and slower the 

reaction. 

Types of fly ash: Pozzolanic activity or reaction of 

fly ash depends upon parameters such as fineness, 

amorphous matter, chemical and mineralogical 

composition and un-burnt carbon contents. 

Effects of fly ash on concrete 

Main influence of fly ash is on water demand and 

workability. For a constant workability, reduction 

in water demand due to flyash is usually between 

5 to 15 percent by comparison with a Portland cement 

only. 

A concrete mix containing fly ash is cohesive and 

has a reduced blending capacity. Reduction in water 

demand of concrete caused by presence of fly ash is 

usually described to their spherical shape, which is 

called “ball-bearing effect” Neville AM (2005). 

However, other mechanisms are also involved and 

may well be dominant. In particular, in consequence 

of electric charge, the finer flyash particles 

become adsorbed on the surface of cement particles. 

If enough fine fly ash particles are present to 

cover the surface of the cement particles, which 

thus become deflocculated, the water demand for a 

given workability is reduced. 

Proportioning of fly ash concrete 

Using of fly ash in concrete has to meet one or more 

of the following objectives. 

• Reduction in cement content 

• Reduced heat of hydration 

• Improved workability and 

• Gaining levels of strength in concrete beyond 90 

days of testing. 

Fly ash is introduced in to concrete by one of the 

following methods. 

• Cement containing fly ash may be used in place 

of OPC 

• Fly ash is introduced as an additional component 

at the time of mixing. 

The first method is simple and problems of mixing 

additional materials are not there, there by uniform 

control is assured. The proportions of fly ash and 

cement are pre determined and mix proportion is 

limited. 

The second method allows for more use of fly ash as 

a component of concrete. Fly ash plays many roles 

such as, in freshly mixed concrete, it acts as a fine 

aggregate and also reduces water cement ratio in 

hardened state, because of its pozzolanic nature, it 

becomes a part of the cementitious matrix and influences 

the strength and durability. 

The assumptions made in selecting an approach to 

mix proportioning fly ash concretes are 

• It reduces the strength of concrete at early stages 

• For same workability, concrete containing fly ash 

requires less water than concrete containing ordinary 

Portland cement. 

The basic approaches that are generally used for 

mix proportioning are 

• Partial replacement of cement 

• Addition of fly ash as fine aggregates and 

• Partial replacement of cement, fine aggregate and 

water 

At earlier stages fly ash exhibits very little cementing 

effects and acts as a fine aggregate, but at later 

ages cementing activity becomes apparent and its 

contribution in the development of strength is observed. 

Applications of Fly ash: 

Fly ash is highly recommended for mass concrete 

applications, i.e. large mat foundations, dams etc. 

Fly ash can be used for the following 

1. Filling of mines. 

2. Replacement of low lying waste land and refuse 

dumps 

3. Replacement of cement mortar 

4. Air pollution control 

5. Production of ready mix fly ash concrete 

6. Laying of roads and construction of embankments 

7. Stabilizing soil for road construction using limefly 

ash mixture 

8. Construction of rigid pavements using cement – 

fly ash concrete 

9. Production of lime –flyash cellular concrete. 

10. Production of precast fly ash concrete building 

units 

11. Production of sintered fly ash light light weight 

aggregate and concrete and 

12. Making of lean-cement fly ash concrete. 

Properties of fresh concrete with fly ash 

Time of setting: the initial setting time of 7.5 h are 

compared to those of control concrete made with 

the water content and water/cementitious materials, 

whereas the final setting time of set were re- 

100


tarded by 3h compared with that of control. 

Bleeding: Bleeding tests performed on high strength 

fly ash concrete have shown that this concrete does 

not bleed. 

Density of fresh concrete: this is comparable to 

the density of Portland cement concrete without fly 

ash. 

Dosage requirement of super plasticizer because 

of the very low water/cementitious materials, the 

use of super plasticizers is mandatory. 

Properties of hardened concrete with fly ash 

Temperature rise: Because of the very low cement 

content the temperature rise in the first few days 

after placement is normal. 

Strength properties: Fly ash concrete exhibits adequatestrength 

development characteristics both at 

early and late ages. 

Young’s modulus of elasticity: The modulus of 

elasticity of fly ash concrete is somewhat higher 

than the modulus of elasticity of probably due to 

the glassy, unhydrated fly ash particles acting as a 

fine filler material in the concrete. 

Creep characteristics: The creep stains of high 

strength fly ash concrete at 1 year is comparable to 

or lower than that of Portland cement concrete of 

comparable strength. 

Fibers 

Plain concrete possesses a very low tensile strength, 

limited ductility and little resistance to cracking. Internal 

micro cracks are inherently present in the 

concrete and its poor tensile strength is due to the 

propagation of such micro cracks, eventually leading 

to brittle fracture of the concrete. 

In plain concrete and similar brittle materials, 

structural cracks (micro cracks) develops even before 

loading, particularly due to drying shrinkage or 

other causes of volume change. The width of these 

initial cracks seldom exceeds a few microns, but 

there two dimensions may be of higher magnitude. 

When loaded, the micro cracks propagate and open 

up and owing to the effect of strength concentration, 

addition cracks from the places of minor defects 

would usually happen. The structural cracks 

proceed or by tiny jumps because they are retarded 

by various obstacles, changes of direction in by 

passing the more resistant grains in matrix. The development 

of such micro cracks is the main cause of 

elastic determination of concrete. 

It has been recognized that the addition of small, 

closely spaced and uniformly dispersed fibres to 

concrete would act as crack arrester and would 

substantially improve its static and dynamic properties 

and does not notably increase the mechanical 

properties before failure but governs the post failure 

behavior. 

Thus, plain concrete which is quasi-brittle material 

is turned on the pseudo ductile material by using 

fibre reinforced. This type of concrete is known as” 

fibre reinforced concrete” 

Short fibres full of steel, glass, carbon or hemp is 

mixed with concrete, which builds the matrix. After 

matrix initialization, the stresses are absorbed by 

bridging fibres and the bending moments are redistributed. 

The concrete element does not fail spontaneously 

when the matrix is cracked; the deformation energy 

is absorbed and the material becomes pseudo-ductile. 

Factors affecting properties of fibre reinforced 

concrete 

Fibre reinforced concrete is the composite material 

containing fibres in the cement matrix in an orderly 

manner or randomly distributed manner. Its properties 

would obviously, depend upon the efficient 

transfer of stress between matrix and the fibres, 

which largely dependent on the type of fibre, fibre 

geometry, fibre content, orientation and distribution 

of the fibres, mixing and compaction techniques of 

concrete, and size and shape of the aggregate. These 

factors are briefly discussed below.The properties of 

various fibres are given in table 

Properties of different types of fibres 

Tensile 

strength ( 

MPa) 

Youngs 

Modulus 

(GPa) 

Ultimate 

elongation 

(%) 

Specific 

Gravity 

Type of fibre 

Acrylic 210-420 2.1 25-45 1.1 

Asbestos 560-980 84-140 0.6 3.2 

Carbon 1800-2400 230-380 0.5 1.9 

Glass 1050-3850 70 1.5-3.5 2.5 

Nylon 770-840 4.2 16-20 1.1 

Polyestor 735-875 8.4 11-13 1.4 

Polyethylene 

700 0.14- 10 0.9 

0.42 

Polypropylene 

560-770 3.5 25 0.9 

Rayon 420-630 7 10-25 1.5 

Rock wool 490-770 70-119 0.6 2.7 

Steel 280-2800 203 0.5-3.5 7.8 

Relative fibre matrix stiffness 

The modulus of elasticity of matrix must be much 

lower than that of fibre for efficient stress transfer. 

Low modulus of fibres such as nylons and polypropylene 

are unlikely to give strength improvement, 

but they help in the absorption of large energy and 

therefore impart greater degree of toughness and 

resistance to impart. High modulus fibres such as 

101


steel, glass and carbon impart strength and stiffness 

to the composite. 

Interfacial bond between the matrix and the fibres 

also determine the effectiveness of stress transfer 

from the matrix to the fibre. A good bond is essential 

for improving tensile strength of the composite. The 

interfacial bond could be improved by larger area of 

contact, improving the frictional properties and degree 

of gripping and by treating the steel fibres with 

sodium hydroxide or acetone. 

Volume of fibres 

The strength of the composite largely depends on 

the quantity of fibres used in it. Increase in the volume 

of fibres, increases linearly the tensile strength 

and toughness of the composite. Use of higher percentage 

of fibre is likely to cause segregation and 

hardness of concrete and mortar. 

Aspect ratio of the fibre 

Another important factor which influences the properties 

and behavior of the composite is the aspect 

ratio of the fibre. 

Orientation of fibres 

One of the differences between conventional reinforcement 

and reinforcement is that in conventional 

reinforcement, bars are oriented in the direction desired 

while fibres are randomly oriented. To see the 

effect of randomness, mortar specimens reinforced 

with 0.5% volume of fibres were tested. In one set 

specimens fibres were aligned in the direction of the 

load, in another in the direction perpendicular to 

that of the load, and in the third randomly distributed. 

It was observed that the fibres aligned parallel to 

the applied load offered more tensile strength and 

toughness than randomly distributed or perpendicular 

fibres. 

Experimental Investigation 

Investigation 

The scope of present investigation is to study 

strength properties on plain concrete, concrete with 

replacement of varying percentages of metakaolin 

and flyash along with steel fibres in different total 

percentages of 0%, 0.5% and 1% for M70 concrete 

mix. 

Materials Used In the Experimentation 

Experimental study is carried out to investigate 

the strength variations in concrete. 

Cement 

Locally available Ordinary Portland Cement of 53 

grade of ULTRATECH Cement brand confirming to 

ISI standards has been procured and following tests 

have been carried out as shown in table 

Physical properties of OPC 53 grade ultratech brand cement 

S.NO Property Test Value Requirements 

as per 

IS:12269- 

1987 

1 Fineness of 

cement 

2 Specific gravity 

3 Normal consistency 

4 Setting time 

Initial setting 

time 

Final setting 

time 

5 Compressive 

strength at 

3 days 

7 days 

28 days 

Fly ash 

4.52 10%(should 

not be more 

than) 

2.99 3.15 

33% - 

40 min 

6 hours 

34N/mm2 

44.8N/mm2 

59N/mm2 

should not be 

less than 30 

min 

should not be 

greater than 

600 min 

27N/ 

mm2(min) 

37N/ 

mm2(min) 

53N/ 

mm2(min) 

Fly ash is the finely divided mineral residue resulting 

from the combustion of coal in electric generating 

plants. Fly ash consists of inorganic, incombustible 

matter present in the coal that has been 

fused during combustion into a glassy, amorphous 

structure. Fly ash particles are generally spherical 

in shape and range in size from 2 μm to 10 μm. 

They consist mostly of silicon dioxide (SiO2), aluminium 

oxide (Al2O3) and iron oxide (Fe2O3). Fly 

ash like soil contains trace concentrations of the following 

heavy metals: nickel, vanadium, cadmium, 

barium, chromium, copper, molybdenum, zinc and 

lead. The chemical compositions of the sample have 

been examined and the flyash are of ASTM C618 

Class F. 

Physical properties of Fly ash 

Color 

Whitish grey 

Bulk density 

0.994 g/cm3 

Specific gravity 2.288 

Moisture % 3.14 

Average particle size 6.12µ 

Metakaolin 

The Metakaolin is obtained from the 20 Microns limited 

Company at Vadodara in Gujarat by the brand 

name Metacem 85 0 C. The specific gravity of Metaka- 

102


olin is 2.5. The Metakaolin is in conformity with the 

general requirement of pozzolana (1,8,12,16). The 

Physical and chemical results are tabulated. 

Physical properties of Metakaolin given by the distributer 

Specific Gravity: 

Physical 

form: 

2.54 D10 particle 

size 

Powder D50 particle 

size 

Colour: Off-White D90 particle 

size 

Brightness: 

BET: surface 

area 

80-82 Hunter 

L 

Bulk 

Density(lbs/ 

ft3): 

15 m2/gram Bulk 

Density(g/ 

cm3): 


Super Plasticizers 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 formaldehyde. 

Super Plasticised concrete is a conventional concrete 

containing a chemical admixture of super 

plasticizing agent. As with super plasticizer admixtures 

one can take advantage of the enhanced workability 

state to make reductions in water cement ratio 

of super plasticized concrete, while maintaining 

workability of concrete. The use of super plasticizers 

in ready mixed concrete and construction reduces 

the possibility of deterioration of concrete for 

its appearance, density and strength. 

On the other hand, it makes the placing of concrete 

more economical by increasing productivity at the 

construction site. Up to 4% by weight of cement is 

used to maintain the workability. 

MIX Design by Doe Method 

The selection of mix materials and their required 

proportion is done through a process called mix design. 

There are number of methods for determining 

concrete mix design. The method that we have 

adopted is called the D.O.E Method which is in 

compliance to the British Standards. The objective 

of concrete mix is to find the proportion in which 

concrete ingredients-cement, water, fine aggregate 

and coarse aggregate should be in order to provide 

the specified strength, workability and durability 

and possibly meet other requirements has listed in 

standards such as IS:456-2000. 

Mix design can be defined as the process of selecting 

suitable ingredients of concrete and determining 

their relative proportions with the objective of producing 

concrete of certain minimum strength and 

durability as economically as possible. The design 

of concrete mix 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 demanded for a particular work 

for which mix is designed. 

Design of concrete mix requires 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 mix 

needs not only the knowledge of material properties 

of concrete in plastic condition, it also needs wider 

knowledge and experience of concerning. Even then 

the proportion of the material of the concrete found 

out at the laboratory requires modifications and readjustments 

to suit the field conditions. 

Details of DOE Method 

The DOE method overcomes some limitations of 

the IS method. In DOE method, the fine aggregate 

content is a function of 600micron passing fraction 

of sand and not the zone of sand. The 600micron 

passing fraction emerges as the most critical parameter 

governing the cohesion and workability of 

concrete mix. Thus sand content in DOE method is 

more sensitive to changes in fineness of sand when 

compared to the IS method. The sand content is 

also adjusted as per workability of mix. 

It is well accepted that higher the workability greater 

is the fine aggregate required to maintain cohesion 

in the mix. The water content per m3 is recommended 

based on workability requirement given in 

terms of slump and Vee-Bee time. It recommends 

different water contents for crushed aggregates and 

for natural aggregates. The quantities of fine and 

coarse aggregates are calculated based on plastic 

density plotted from graphs. However the DOE 

method allows simple correction in aggregate quantities 

for actual plastic density obtained at laboratory. 

Procedure of Mix Design 

Step 1:Assume standard deviation =5 N/mm2 

Assume slump of concrete =75 mm 

Step 2: Find the target mean strength from the 

specified characteristic strength. 

Target mean strength = specified characteristic 

strength + standard deviation * risk factor. 

Step 3: Calculate the water/cement ratio using table 

and figure shown below. 

Table gives approximate compressive strength of 

concrete made with a free w/c ratio of 0.50. Using 

this table find 28 days strength for the approximate 

type of cement and types of C.A mark a point on 

the Y-axis in fig equal to the compressive strength 

read from the table which is at a w/c ratio of 0.50. 

Through this intersection point, draw a parallel doted 

curve nearest to the intersection point. Using the 

new curve we read of w/c ratio as against target 

mean strength. 

Step 4: Decide water content water require workability 

express in terms of slump or Vee-Bee time 

taking into consideration the size of aggregate and 

its type. 

Step 5: Find the cement content knowing the w/ c 

ratio and the water content. 

Step 6: Find out the total aggregate content and find 

out wet density of fully compacted aggregates. The 

value of specific gravity of 2.7 for crushed aggregate 

can be taken. The aggregate content is obtained by 

subtracting the weight of cement and water content 

from weight of fresh concrete. 

Step 7: Proportion of fine aggregate is determine in 

the total aggregate. Maximum size of coarse aggregate, 

the level of workability, w/c ratio and the percentage 

of fine passing 600micron sieve. Once the 

proportion of fine aggregate is obtained multiplying 

by the weight of total aggregate gives the weight if 

fine aggregate. Then the weight of the C.A can be 

found out. 

104


Calculation for M70 Mix Design: 

Materials 

Cement : OPC 53 grade 

Coarse aggregates : crushed stone of size 20mm 

down graded 

Fine aggregates : natural river sand locally available 

Step by Step Calculations 

Step 1: 

Assume standard deviation=5 N/mm2 

Assume slump of concrete=75 mm 

Step 2: 

Target mean strength = (specific characteristic 

strength) + (standard deviation * riskfactor) =70 + 

(5*1.65)=78.25 Mpa 

Step 3: 

W/C for 78.25 MPa = 0.32 

Step 4: 

Water content for slump of 75mm and 20mm uncrushed 

aggregates =195kg/m3 

Step 5: 

With W/C ratio of 0.28 and water content of 195 

kg/m3 

The cement content = 195/0.32= 625 kg 

Step 6: 

For water content of 195 kg/m3,20mm uncrushed 

aggregate of specific gravity of 2.64, the density of 

fresh concrete i.e., wet density =2450 

Weight of total aggregates =2450-(195+609.38) 

=1645.63 kg/m3 

Step 7: 

For 20mm size aggregate, w/c ratio of 0.32, slump 

of 75mm and for 50% of fines passing through 600 

micron sieve, the percentage of fine aggregate =36% 

Step 8: 

Weight of fine aggregate = 1645.63*(36/100) 

=592.43 kg/m3 

Step 9: 

Weight of coarse aggregate =1645.63-592.43 

=1053.20 kg/m3 

Estimated quantities for 1m3 of concrete 

Cement 

Fine aggregate 

Coarse aggregate 

Water 

=609.38 kg 

=592.43 kg 

=1053.20 kg 

=195 kg 

The ratio comes out to be 1:0.97:1.7 

Trial Mixes 

After several trial mixes we got the Mix proportions 

as 1: 1.12: 1.68 

Cementv= 625 kg 

Fine aggregate =701.44kg 

Coarse aggregate = 1052.1 kg 

Water 

=150 kg 

W/C = 0.28 

Super plasticizer =0.9 

Triple Blending With Mineral Admixtures 

In the present investigation triple blending cement 

concrete mixes have been tried for various strength 

properties. Mineral admixtures like flyash and metakaolin 

have been employed along with cement and 

triple blended cement concrete mixes are prepared. 

The percentages of Flyash are 0%, 15%, 25% and 40 

%. The percentages of metakaolin are 0%, 5%, 10% 

and 15%. Both the mineral admixtures are added 

simultaneously to OPC to carry out triple blending. 

In addition steel fibres are added in percentages of 

0%, 0.5% and 1.0% to the triple blended concrete. 

The various combinations of fibrous triple blended 

concrete nixes tried in the present investigation are 

given in table 

In total there are 48 combinations. 

Various Combinations of Fibrous Triple Blended Cement 

Concrete 

S.No Mix no. Cement F.A Metacem 

Fibre 

1 C1 100 0.0 0.0 0.0 

2 C2 100 0.0 0.0 0.5 

3 C3 100 0.0 0.0 1.0 

4 C4 95 0.0 5.0 0.0 

5 C5 95 0.0 5.0 0.5 

6 C6 95 0.0 5.0 1.0 

7 C7 90 0.0 10 0.0 

8 C8 90 0.0 10 0.5 

9 C9 90 0.0 10 1.0 

10 C10 85 0.0 15 0.0 

11 C11 85 0.0 15 0.5 

12 C12 85 0.0 15 1.0 

13 C13 85 15 0.0 0.0 

14 C14 85 15 0.0 0.5 

15 C15 85 15 0.0 1.0 

16 C16 80 15 5.0 0.0 

17 C17 80 15 5.0 0.5 

18 C18 80 15 5.0 1.0 

19 C19 75 15 10 0.0 

20 C20 75 15 10 0.5 

21 C21 75 15 10 1.0 

22 C22 70 15 15 0.0 

23 C23 70 15 15 0.5 

105


24 C24 70 15 15 1.0 

25 C25 75 25 0.0 0.0 

26 C26 75 25 0 0.5 

27 C27 75 25 0.0 1.0 

28 C28 70 25 5.0 0.0 

29 C29 70 25 5.0 0.5 

30 C30 70 25 5.0 1.0 

31 C31 65 25 10 0.0 

32 C32 65 25 10 0.5 

33 C33 65 25 10 1.0 

34 C34 60 25 15 0.0 

35 C35 60 25 15 0.5 

36 C36 60 25 15 1.0 

37 C37 60 40 0.0 0.0 

38 C38 60 40 0.0 0.5 

39 C39 60 40 0.0 1.0 

40 C40 55 40 5.0 0.0 

41 C41 55 40 5.0 0.5 

42 C42 55 40 5.0 1.0 

43 C43 50 40 10 0.0 

44 C44 50 40 10 0.5 

45 C45 50 40 10 1.0 

46 C46 45 40 15 0.0 

47 C47 45 40 15 0.5 

48 C48 45 40 15 1.0 

Mixing Of Concrete 

Initially the ingredients of concrete viz., coarse aggregate, 

fine aggregate cement and Metakaolin were 

mixed to which the fine aggregate and coarse aggregate 

were added and thoroughly mixed. Water 

was measured of uniform colour and consistency 

was achieved which is then ready or casting. Prior 

to casting specimens, Workability is measured in 

accordance and is determined by slump test and 

compaction factor test. Super plasticizer SP430 

supplied by M/S.Fosroc (India) Ltd. was added upto 

1% to maintain the mix in workable condition as 

shown in photographs. 

Workability 

The following tests have been done to measure the 

workability of concrete according to Indian Standard. 

Slump test 

Slump 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 =20cm 

Top diameter of frustum of cone =10cm 

Height of the cone 

=30cm 

The initial surface of the mould is thoroughly 

cleaned. The mouldis placed on a smooth horizontal 

right and non-absorbent surface. The mould is 

then filled four layers approximately one fourth of 

the height of the mould. Each layer is tamped 25 

times by tamping rod taking care to distribute the 

strokes evenly over the cross section. After 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 referred 

as slump of concrete. The difference in level between 

the height of the mould and that of the highest point 

of the subsided concrete is measured. This difference 

in height in mm is taken as slump of concrete. 

Compaction factor test 

The compaction factor test is more precise and sensitive 

than the slump test and is particularly useful 

for concrete mix of low workability. It measures the 

workability of concrete interms of internal energy 

required to compact the concrete fully. The apparatus 

consists of two hoppers, each in shape of frustum 

of a cone and one cylinder. The 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 

therefore filled to overflowing and this always contains 

approximately the same amount of concrete in 

standard state this reduces the influence of the personnel 

and the concrete falls into the cylinder. Excess 

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. 

CF= 

(Partially compacted concrete) 

(Fully compacted concrete) 

To maintain medium workability (C.F= 0.85 to 0.9) 

by adding super plasticisers whenever necessary. 

Casting of Specimens 

The cubes were cast in steel moulds of inner dimensions 

of 100*100*100mm. All materials i.e., cement, 

Metakaolin, flyash, fine aggregate, coarse aggregate, 

super plasticizer. The cement, sand, flyash and metakaolin 

were mixed thoroughly by manually. Approximately 

25% of water required added and mixed 

thoroughly with a view to obtain uniform mix. After 

that the balance of 75% of water was added and 

mixed thoroughly with a view to obtain uniform 

mix. When fibres are used they should be soaked 

for a minute in water. This water is then added to 

the cement batch. 

For all test specimens, moulds were kept on 

table vibrator and concrete was poured into the 

moulds in three layers by tamping with a tamping 

rod and the vibration was effected by table vibrator 

after filling of the moulds. The vibration was effected 

106


for one minute and it was maintained constant for 

all the specimens. The moulds were removed after 

24 hours and the specimens were kept immersed 

in a clear water tank. After curing the specimens 

in water for a period of 28 days the specimens were 

removed out and allowed to dry under shade. 

SpecimensCasted 

• Combinations : 48 

• No of samples per combinations : 4 (2cubes & 2 

prisms) 

• Total no of samples : 48*4=192 

Test Setup and Testing 

The cube specimens cured as explained above are 

tested as per standard procedure I.S.516, after removal 

from curing tank and allowed to dry under 

shade. The cube specimens are tested for 

• Compressive strength test 

• Flexural strength test 

Compressive strength test 

Age at test 

Tests shall be made at recognized ages of the test 

specimens, the most usual being 7 and 28 days. 

The ages shall be calculated from the time of addition 

of water to the dry ingredients. 

Procedure 

Specimens stored in water shall be tested immediately 

on removal from the water and while they 

are still in the wet condition. Surface water and grit 

shall be wiped off the specimens and any projecting 

fins removed. 

Placing the specimens in the testing machine 

The bearing surfaces of the testing machine shall be 

wiped clean and any loose sand or other material removed 

from the surfaces of the specimen which are 

to be in the contact with the compression platens. 

In the case of cubes, the specimen shall be placed in 

the machine in such a manner that the load shall be 

applied to opposite sides of the cubes as cast, i.e., 

not to the top and bottom. 

The axis of the specimen shall be carefully aligned 

with the centre of thrust of the spherically seated 

platen. No packing shall be used between the faces 

of the test specimen and steel platen of the testing 

machine. The load shall be applied without shock 

and increased continuously at a rate of approximately 

140kg/cm2/min until the resistance of the 

specimen to the increasing load breaks down and 

no greater load can be sustained. 

The maximum load applied to the specimen shall 

then be recorded and the appearance of the concrete 

and any unusual features in the type of failure 

shall be noted. 

Calculation 

The measured compressive strength of the specimen 

shall be calculated by dividing the maximum 

load applied to the specimen during the test by the 

cross sectional area and shall be expressed to the 

nearest kg/cm2. 

Cube compressive strength was tested and results 

were tabulated. 

Flexural strength test 

Apparatus 

The testing machine may be of any reliable type of 

sufficient capacity for the tests and capable of applying 

the load at the rate specified in 3.10.2.2. The 

bed of the testing machine shall be provided with 2 

steel rollers 38mm in diameter, on which the specimen 

is to be supported, and these rollers shall be so 

mounted that the distance from centre to centre is 

60cm for 15cm specimen or 40cm for 10cm specimens. 

The load shall be applied through 2 similar 

rollers mounted at the third points of the supporting 

span, i.e., spaced at 20 or 13.3cm centre to centre. 

The load shall be divided equally between the 2 

loading rollers and all rollers shall be mounted in 

such a manner that the load is applied axially and 

without subjecting the specimen to any torsional 

stresses or restraints. 

Procedure 

Test specimens stored in water at a temperature 

of 24-30 0 C shall be tested immediately on removal 

from water while they are still in a wet condition. No 

preparation of the surface is required. 

Placing the specimen in the testing machine 

The bearing surfaces of the supporting and the 

loading rollers shall be wiped clean and any loose 

sand or other material removed from the surfaces of 

the specimen where they are to make contact with 

the rollers. 

The specimen shall then be placed in the machine 

in such a manner that the load shall be applied to 

the upper most surface as cast in the mould, along 

2 lines spaced 20 or 13.3 cm apart. The axis of the 

specimen shall be carefully aligned with the axis of 

the loading device. 

No packing shall be used between the bearing surfaces 

of the specimen and the rollers. The load shall 

be applied without shock and increasing continuously 

at a rate such that the extreme fibre stress 

increases at approximately 7kg/cm2/min i.e., at a 

rate of loading of 400kg/min for the 15cm specimen 

and at a rate of 180kg/min for the 10cm specimen. 

The load shall be increased until the specimen fails, 

and the maximum load applied to the specimen 

during the test shall be recorded. The appearance of 

107


the fractured faces of the concrete and any unusual 

features in the type of failure shall be noted. 

Curing of the specimens 

Calculation 

The flexural strength of the specimen shall be expressed 

as the modulus of rupture 

Modulus of rupture = 

Load*Span 

Breadth*Depth*Depth 

Pan mixer 

Testing for Compression 

Casting of the specimens 

Testing for Flexure 

Vibration Table for Compaction 

Failure pattern of the beam 

108


Results and Discussions 

Presentation of Results 

The present project deals with the flexural properties 

of Fibrous Triple Blended High Strength Cement 

Concrete. Triple blending was carried out by replacing 

OPC with flyash and metakaolin in various percentages. 

Percentage of steel fibers has varied from 

0.0% to 1.0%. The reference concrete mix is of M70 

grade. There are in total 48 combinations of mixes 

(table 3.1) tried in the present investigation. The average 

28 day compressive strength results are given 

in table 4.1. The compressive strength results are 

also plotted and shown in figures 4.1 to 4.6.The 

values of ultimate load and the corresponding deflection 

recorded for various specimens are given in 

table 4.2. The flexural strength results are also plotted 

and shown in figures 4.7 to 4.12. Typical load 

(vs) deflection values are given in tables 4.3 to 4.15. 

The load (vs) deflection relationships for the same 

are plotted and shown in figures 4.13 to 4.24. 

High Strength Concrete Mixes 

To derive higher compressive and flexural strengths 

high strength concrete mixes are required. They are 

designed by any one of the available methods like 

DOE method, ACI method etc and by trial. In the 

modern constructions of various large and prestigious 

structures like long span bridges ,prestressed 

concrete bridges,very tall multi storeyed buildings 

high strength and high performance concrete mixes 

are being employed. In the case of high strength 

concrete mixes the quantity of cement required per 

cubic metre of concrete is very high. In the present 

M70 design mix the quantity of cement per cubic 

metre of concrete is 625 kg and it will be more for 

still higher strengths. By using mineral admixtures 

like flyash, metakaolin, condensed silica fume (CSF), 

GGBS etc as replacement to cement by certain proportion, 

the quantity of cement can be reduced and 

more economical concrete mixes can be used. 

In addition to this mineral admixtures impart many 

other beneficial properties to concrete. Hence adding 

certain dosage of mineral admixture as replacement 

to OPC is essential for High Performance Concrete 

(HPC). 

To increase the tensile and flexural strengths of high 

strength concrete certain percentage of steel fiber 

is added. Addition of steel fiber also helps in the 

reduction of cracks, impart strength and ductility. 

By adding two admixtures instead of one, additional 

advantage can be derived. This is the basis for production 

of Fibrous Triple Blended Cement Concrete 

(FTBCC) in the present project work. 

Workability of Triple Blended Mixes 

In the present reference M70 design mix, the water 

cement ratio is 0.28 which is lower as such the 

concrete mix becomes sufficiently hard with low 

workability. In addition mineral admixtures and 

steel fibres are also being added to develop optimum 

FTBCC. As a result the workability gets further reduced. 

To maintain the workability almost at medium 

level super plasticizer (CONPLAST 430) has 

been employed at a percentage varying from 0.8% to 

1.0%. This enables concrete to be mixed thoroughly 

and cast the specimens without voids and dense. 

Hence, it is necessary to use super plasticizer to 

maintain the workability level in the case of high 

strength concrete mixes where the W/C ratio is low. 

Compressive Strength Results 

By referring to table 4.1 and figures 4.1 to 4.6, it 

can be seen that in general with the increase in fibre 

percentage the compressive strength gets increased 

for all combinations. Considering various combinations, 

it can also be seen that as the flyash percentage 

is increased the strength gets reduced for 

a given percentage of metakaolin and percentage of 

fibre. Similarly with increase in metakaolin percentage 

the strength gets gradually increased. It is noted 

that 15% of metakaolin gives the highest compressive 

strength for various combinations. Adding fibres 

contributes towards increase in compressive 

strength to some extent. 

For example the compressive strength of basic reference 

mix is 76.8 N/mm2. The compressive strength 

of concrete mix with 0% flyash,15% metakaolin and 

0% fibre is 83.5N/mm2. There is an increase of 9% 

in the compressive strength. The same mix with 1% 

fibre has a compressive strength of 86.20 N/mm2 

showing a total increase of 12% compared to the reference 

mix. It can be seen that flyash is contributing 

towards strength increase marginally upto 15% 

only. With 15% flyash,15% metakaolin and 1% fibre 

the highest compressive strength recorded is 86.50 

N/mm2. 

This is the optimum mix showing a maximum increase 

of nearly 13% in compressive strength compared 

to the reference mix. So beyond 15% of flyash 

in the mix there is gradual decrease in the compressive 

strength. 

Hence an optimum combination of flyash and metakaolin 

is to be struck to obtain the optimum compressive 

strength. Beyond 15% metakaolin strength 

again gets decreased. A combination of 15% flyash 

and 15% metakaolin in triple blended concrete mix 

generates highest strength. Addition of steel fibres 

contribute towards increase in compressive strength 

to certain extent. 

Flexural Strength Results 

By referring to table 4.2 and figures 4.7 to 4.12, it 

can be seen that in general with the increase in fibre 

percentage the flexural strength gets increased 

for all combinations. Considering various combinations, 

it can also be seen that as the flyash percentage 

is increased the strength gets reduced for 

109


a given percentage of metakaolin and percentage 

of fibre. Similarly with increase in metakaolin percentage 

the strength gets gradually increased for a 

given combination. It is noted that 15% of metakaolin 

gives the highest flexural strength for various 

combinations. Adding fibres contributes towards 

increase in flexural strength . 

For example the flexural strength of basic reference 

mix is 4.2 N/mm2. The compressive strength of concrete 

mix with 0% flyash, 15% metakaolin and 0% 

fibre is 4.8 N/mm2. There is an increase of 14% in 

the flexural strength compared to the reference mix. 

The same mix with 1% fibre has a flexural strength 

of 5.8 N/mm2 showing a total increase of 38% compared 

to the reference mix. 

It can be seen that flyash is contributing towards 

strength increase marginally upto 15% only. With 

15% flyash,15% metakaolin and 1% fibre the highest 

flexural strength recorded is 6.4 N/mm2. 

This is the optimum mix showing a maximum increase 

of nearly 52% in flexural strength compared 

to the reference mix. So beyond 15% of flyash in 

the mix there is gradual decrease in the flexural 

strength. 

Hence flexural strength of triple blended mix increases 

with increase in fibrepercentage.In the case 

oftriple blended cement concrete mixes 15% flyash 

with 15% metakaolin and 70% OPC can be taken as 

the optimum combination to give optimum flexural 

strength. 

With the addition of steel fibres the flexural strength 

further increases. With an optimum combination of 

15% flyash,15% metakaolin and 1% fibre,there is 

an increase of nearly 52% in the flexural strength. 

Role of Fibers 

Even in the case of triple blended cement concrete 

mixes,steelfibres contribute towards strength increase. 

Presence of fibres increases the compressive 

strength of the matrix to certain extent. In the 

present experimental investigation it was found that 

1% fibre has increased the compressive strength 

upto 13% compared to the reference mix without 

mineral admixtures. In the case of optimum mix 

having 15% flyash and 15% metakaolin there is a 

further increase in compressive strength by nearly 

4% with the addition of 1% fibres. 

A similar tendency of compressive strength results 

can be observed even in the case of flexural strength 

results also. Without flyash and metakaolin and 1% 

fibre the flexural strength is increased by 14% nearly. 

With 15% flyash,15% metakaolin and 0% fibre 

the increase in flexural strength is 14% nearly. In 

the case of the optimum combination of 15% flyash,15% 

metakaolin and 1% fibre,there is a maximum 

increase of 52% nearly compared to the reference 

mix. 

Hence,steel fibres contribute towards increase in 

the compressive strength to some extent .But the 

flexural strength is increased substantially with the 

presence of fibres in the matrix. In the case of triple 

blended cement concrete mixes addition of fibres 

would help to produce an optimum fibrous concrete 

having higher values of both compressive strength 

and flexural strength. 

Cracking Characteristics 

All the beams were tested for flexure in the present 

investigation. The reference beam without mineral 

admixtures and fibre has undergone brittle failure. 

It has failed suddenly at the ultimate flexural load 

just with one crack occurring. 

Even in the case of triple blended cement concrete 

specimens,the flexural failures is brittle when there 

are no fibres. There is a difference in the flexural 

behaviour of the specimens having steel fibres. In 

the case of fibrous specimens it is observed that 

cracking has started somewhere between 50 to 70% 

of the ultimate load, it is followed by more cracks 

as the load is increased. The failure behaviour is 

gradual and ductile. Finally it is observed that at 

the ultimate load even when the specimen has become 

into two pieces they are held in position by the 

fibres without dropping down. Hence it is clear that 

the fibres have contributed towards gradual cracking 

behaviour and ductility. 

Flexural Deformations and Ductility 

Steel fibres have contributed for gradual increase in 

deformations in the flexural specimens. In the case 

of reference mix without any admixture and fibre, 

the ultimate load is 10.5 KN and the corresponding 

ultimate deflection is 0.3mm. These values have 

become 12 KN and 0.42 mm with 1% fibre. In the 

case of triple blended mix with 15% flyash and 15% 

metakaolin, the ultimate load recorded is 13 KN and 

the corresponding deflection is 0.50 mm. For the 

same mix the ultimate load has increased to 15 KN 

and the ultimate deflection has become 0.54 mm. 

In general it is observed that the presence of fibres 

is contributing towards the increase in the flexural 

load as well as the flexural deformation. 

Hence fibrous specimens show better deformation 

characteristics, they have recorded higher ultimate 

flexural load and higher flexural deformation. 

Ductility Characteristics 

In general it is observed that the fibrous specimens 

are showing more ductile flexural behaviour. It is 

seen that in the case of fibrous specimens, flexural 

deformation is more at a particular load compared 

to that of specimens without fibre. 

Hence by incorporating steel fibers by certain percentage 

in triple blended cement concrete mixes 

there is not only an increase in the flexural load but 

110


also in the flexural deformations resulting in more 

ductility. 

Optimum Combinations 

Based on the experimental study conducted on various 

combinations of fibrous triple blended cement 

concrete mixes of high strength, it is concluded 

that 15% flyash with 15% metakaolin combination 

gives the highest compressive strength. From the 

fiber percentages tried, 1% fibre is giving the highest 

compressive as well as flexural load. Hence 15% 

flyash plus 15% metakaolin with 1% fiber is found 

to be optimum from study undertaken. 

Overall Recommendations 

High strength high performance concrete mixes are 

prepared with the addition of mineral admixtures 

like flyash, metakaolin, CSF are added in certain 

percentage as replacement to OPC to achieve higher 

strengths,economy and many other beneficial properties. 

As fibres impart higher flexural strength, it 

is an added property to high performance concrete. 

Hence it is recommended that not only a certain percentage 

of steel fibre makes high performance concrete 

with more desirable properties. In the present 

project work durability properties are not included. 

Compressive Strength Results 

S.No 

(%) 

Mix 

no 

OPC 

(%) 

Flyash 

(%) 

Metacem 

(%) 

Fiber(%) 

Avg compressive 

strength (N/ 

mm2) 

1 C1 100 0 0 0 78.84 

2 C2 100 0 0 0.5 80.30 

3 C3 100 0 0 1.0 82.15 

4 C4 95 0 5 0 79.20 

5 C5 95 0 5 0.5 81.50 

6 C6 95 0 5 1.0 82.75 

7 C7 90 0 10 0 82.50 

8 C8 90 0 10 0.5 83.45 

9 C9 90 0 10 1.0 84.50 

10 C10 85 0 15 0 83.50 

11 C11 85 0 15 0.5 84.50 

12 C12 85 0 15 1.0 86.20 

13 C13 85 15 0 0 78.00 

14 C14 85 15 0 0.5 80.00 

15 C15 85 15 0 1.0 82.00 

16 C16 80 15 5 0 78.50 

17 C17 80 15 5 0.5 81.50 

18 C18 80 15 5 1.0 84.24 

19 C19 75 15 10 0 82.00 

20 C20 75 15 10 0.5 83.00 

21 C21 75 15 10 1.0 85.00 

22 C22 70 15 15 0 83.00 

23 C23 70 15 15 0.5 85.00 

24 C24 70 15 15 1.0 86.50 

25 C25 75 25 0 0 73.93 

26 C26 75 25 0 0.5 76.47 

27 C27 75 25 0 1.0 79.65 

28 C28 70 25 5 0 78.00 

29 C29 70 25 5 0.5 81.15 

30 C30 70 25 5 1.0 82.50 

31 C31 65 25 10 0 80.00 

32 C32 65 25 10 0.5 82.50 

33 C33 65 25 10 1.0 83.75 

34 C34 60 25 15 0 83.00 

35 C35 60 25 15 0.5 83.50 

36 C36 60 25 15 1.0 84.75 

37 C37 60 40 0 0 68.00 

38 C38 60 40 0 0.5 68.50 

39 C39 60 40 0 1.0 71.75 

40 C40 55 40 5 0 69.50 

41 C41 55 40 5 0.5 70.50 

42 C42 55 40 5 1.0 72.25 

43 C43 50 40 10 0 72.15 

44 C44 50 40 10 0.5 73.25 

45 C45 50 40 10 1.0 74.50 

46 C46 45 40 15 0 74.75 

47 C47 45 40 15 0.5 75.25 

48 C48 45 40 15 1.0 76.00 

Flexural Strength Results 

S.No. 

OPC 

Mixno. 

Flyash 

Metacem 

Fiber 

Ult. 

Load 

KN 

Flex 

ural 

stre 

ngth 

N/ 

mm2 

Defl 

etion 

1 C1 100 0 0 0 10.5 4.2 0.3 

2 C2 100 0 0 0.5 11.5 4.6 0.32 

3 C3 100 0 0 1.0 12.0 4.8 0.34 

4 C4 95 0 5 0.0 11.0 4.4 0.31 

5 C5 95 0 5 0.5 13.5 5.4 0.32 

6 C6 95 0 5 1.0 15.5 6.2 0.35 

7 C7 90 0 10 0.0 11.5 4.6 0.33 

8 C8 90 0 10 0.5 12.0 4.8 0.34 

9 C9 90 0 10 1.0 15.6 5.8 0.36 

10 C10 85 0 15 0.0 12.0 4.8 0.34 

11 C11 85 0 15 0.5 12.5 5.0 0.36 

12 C12 85 0 15 1.0 15.8 5.8 0.37 

13 C13 85 15 0 0.0 11.0 4.4 0.31 

14 C14 85 15 0 0.5 12.5 5.0 0.32 

15 C15 85 15 0 1.0 13.5 5.4 0.33 

16 C16 80 15 5 0.0 11.5 4.6 0.40 

17 C17 80 15 5 0.5 13.0 5.2 0.44 

18 C18 80 15 5 1.0 14.5 5.8 0.46 

19 C19 75 15 10 0.0 11.7 4.7 0.35 

20 C20 75 15 10 0.5 12.5 5.0 0.38 

21 C21 75 15 10 1.0 15.0 6.0 0.47 

22 C22 70 15 15 0.0 12.2 4.8 0.45 

23 C23 70 15 15 0.5 13.0 5.2 0.50 

24 C24 70 15 15 1.0 16.0 6.4 0.54 

25 C25 75 25 0 0.0 10.0 4.0 0.30 

111


26 C26 75 25 0 0.5 10.7 4.2 0.31 

27 C27 75 25 0 1.0 11.5 4.6 0.33 

28 C28 70 25 5 0.0 10.5 4.2 0.31 

29 C29 70 25 5 0..5 11.2 4.5 0.33 

30 C30 70 25 5 1.0 11.5 4.7 0.35 

31 C31 65 25 10 0.0 12.0 4.6 0.32 

32 C32 65 25 10 0.5 12.5 5.0 0.33 

33 C33 65 25 10 1.0 13.0 5.2 0.35 

34 C34 60 25 15 0.0 12.6 5.0 0.33 

35 C35 60 25 15 0.5 13.7 5.5 0.34 

36 C36 60 25 15 1.0 14.5 5.6 0.35 

37 C37 60 40 0 0.0 8.7 3.5 0.29 

38 C38 60 40 0 0.5 9.5 3.8 0.30 

39 C39 60 40 0 1.0 10.0 4.0 0.31 

40 C40 55 40 5 0.0 9.2 3.7 0.30 

41 C41 55 40 5 0.5 9.7 3.9 0.32 

42 C42 55 40 5 1.0 10.5 4.2 0.33 

43 C43 50 40 10 0.0 9.7 3.9 0.31 

44 C44 50 40 10 0.5 10.5 4.2 0.32 

45 C45 50 40 10 1.0 11.0 4.4 0.34 

46 C46 45 40 15 0.0 10.5 4.2 0.32 

47 C47 45 40 15 0.5 11.0 4.4 0.33 

48 C48 45 40 15 1.0 11.5 4.6 0.34 

Fig Average compressive strength (vs) metakaolin percentage for 

0.5 % fibre and flyash 15% and 40 % 


1 % fiber and flyash 0% and 25% 

FIG Average compressive strength (vs) metakaolin percentage for 

0 % fibEr and flyash 0% and 25% 


0.5 % fibre and flyash 15% and 40 % 


0 % fiber and flyash15% and 40 % 

Fig Load (vs) Deflection for FTBCC beam No’s 2 & 8 

112


Load (vs) Deflection for FTBCC beam No’s 3 & 9 



Ultimate flexural load (vs)flyash percentage for 0% fiber and 

metakaolin 0% and 5% 


Ultimate flexural load (vs) flyash percentage for 0.5 % fiber 

And metakaolin 0% and 5% 


Ultimate flexural load (vs) flyash percentage for 1 % fiber and 

metakaolin 0% and 5% 

113


in fibre percentage. 

7.In the case of triple blended cement concrete mixes 15% flyash 

with 15% metakaolin and 70% OPC can be taken as the optimum 

combination to give optimum flexural strength. With the 

addition of steel fibres the flexural strength further increases. 

8.With an optimum combination of 15% flyash,15% metakaolin 

and 1% fibre there is an increase of nearly 52% in the flexural 

strength. 

9.Steel fibres contribute towards increase in the compressive 

strength to some extent .But the flexural strength is increased 

substantially with the presence of fibres in the matrix. 

Ultimate flexural load (vs) flyash percentage for 0% fiber 

andmetakaolin 10 % and 15 % 

10.In the case of triple blended cement concrete mixes addition 

of fibres would help to produce an optimum fibrous concrete 

having higher values of both compressive strength and flexural 

strength. 

11.It is clear that the fibres have contributed towards gradual 

cracking behaviour and ductility. 

12.Fibrous specimens show better deformation characteristics, 

they have recorded higher ultimate flexural load and higher 

flexural deformation. 

13.By incorporating steel fibres by certain percentage in triple 

blended cement concrete mixes there is not only an increase in 

the flexural load but also in the flexural deformations resulting 

in more ductility. 

14.15% flyash plus 15% metakaolin with 1% fibre is found to be 

optimum from study undertaken. 

Ultimate flexural load (vs) flyash percentage for 0.5 % fiber 


15.It is recommended that not only a certain percentage of steel 

fibre makes high performance concrete with more desirable 

properties. 

References 

1) Abeles PW, Bardhan-Roy BK. Prestressed concrete designer’s 

handbook. In: cement and concrete association .Wexham 

Springs: A Viewpoint publication;1981.F.W. Lydon, concrete mix 

design, 2nd ed., Applied science, London, 1982. 

2) JASS 5(Revised 1979); Japanese Architectural Standard for 

Reinforced Concrete, Architectural Institute of Japan, Tokyo, 

1982(March). 

3) Nevile, A.M., Properties of Conrete, 4th Edition, Longman, 

England, 1995.I.S:10262- 2009, “recommended guide lines for 

concrete mix design”.BIS. 

Ultimate flexural load (vs) flyash percentage for 1 % fiber 


Conclusions 

1.Based on the present project work on Fibrous Triple Blended 

High Strength Cement Concrete mixes-study of compressive 

and flexural strength characteristics, the following conclusions 

are drawn. 

2. It is necessary to use super plasticizer to maintain the workability 

level in the case of high strength concrete mixes where 

the W/C ratio is low. 

3.An optimum combination of flyash and metakaolin is to be 

struck to obtain the optimum compressive strength. Beyond 

15% metakaolin strength again gets decreased. 

4.A combination of 15% flyash and 15% metakaolin in triple 

blended concrete mix generates highest strength. 

5.Addition of steel fibres contribute towards increase in compressive 

strength to certain extent. 

6.Flexural strength of triple blended mix increases with increase 

4) I.S: 516 – 1959: “Indian standard Methods of Tests for strength 

of Concrete” – Bureau of Indian Standards. 

5) I.S: 4037 – 1988 : “Indian standard methods of physical test 

for Hydraulic cement” – Bureau of Indian Standards. 

6) IS: 1344 – 1968 : “Indian standard specifications for pozzalonas” 

- Bureau of Indian Standards. 

7) I.S: 2386 – 1963 : “Indian Standards methods for aggregates of 

concrete” – Bureau of Indian standards, New Delhi 

8) I.S: 380 – 1970 : “Indian standard specifications for coarse and 

fine aggregates (natural)” - Bureau of Indian Standards (revised). 

9) I.S : 456 – 2000 : Plain and reinforced concrete Indian standard 

specifications 

10) M.S Shetty : “Concrete Technology” – 2006. 

11) N. Krishnaraju : “Design of concrete mix” – CBS publisher 

– 1985. 

12) Bredy,P.etal’Microstructure and porosity of metakaolin 

blended cements’ProcMater,ResSocSymp 1989;137;431-6. 

114


13) I.S 12269-1987,”Specification for 53 grade ordinary Portland 

cement”,BIS. 

14) Swammy and Hannat,’Fibre Reinforced Concrete. 

15) P.K.Mehtha&J.J.M.Paulo,”concrete micro structure properties 

and materials”-Mc Graw Hill publishers 1997. 

Authour 

K. Mythili 

M.Tech(Structural Engineering), 

Associate Proffesor At Aurora S Scientific And Technological 

And Research Academy, 

Bandlaguda, Hyderbad - 500005, 

India. 

C.Dheeraj 

Research Scholar, 

Department of Civil Engineering,At Aurora S Scientific And 

Technological And Research Academy, Bandlaguda, 

Hyderbad - 500005, India. 

B.L.P. Swami 

Professor and Co-ordinator, 

Research and Consultancy, VCE, 

Hyderabad,India 

115

Flexural Behavior of Fibrous Reinforced Cement Concrete Blended With Fly

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