14532154 Experimental Study of Strenth of Latex Modified Fibre Reinforced Concrete

8/10/2019 14532154 Experimental Study of Strenth of Latex Modified Fibre Reinforced Concrete

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EXPERIMENTAL STUDY OF STRENTH OF

LATEX MODIFIED FIBRE REINFORCED

CONCRETE

BY

A.DEVI PRASADH

MANUEL MARTIN

NANDAKUMAR

DEPARTMENT OF CIVIL ENGINEERING

HINDUSTAN COLLEGE OF ENGINEERING

(AFFILIATED TO ANNAUNIVERSITY)CHENNAI-603103


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SYNOPSIS

Latex modified mortar and concrete provide a good workability, water

retention over conventional cement mortar & concrete .In contrast to

ordinary cement mortar and concrete which are apt to cause bleedingand segregation, the resistance of latex modified mortar & concrete tobleeding and segregation is excellent in spite of their larger flow ability

characteristics. Setting time of latex modified mortar & concrete isdelayed in some extent. In concrete the tensile & flexural strengths are

improved over a normal concrete but in compressive strength there isno improvement.

The polymercement ratio has more pronounced effect on the strengththan the water cement ratio. !hen the sandcement ratio increases, the

flexural and compressive strength of latexmodified mortars are

remarkably reduced, and the effect of the latex cement ratio on thestrengths gradually becomes smaller.

In the present work concrete has been modified using latex as the

polymer .In addition steel fibres have been added to check combinedproperties of concrete.

In general there is increase in compressive, tensile & flextural strength

with increase in fibre and latex.

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INTRODUCTION

#ngineering achievements have always been closely associated with

the availability of suitable materials for construction. $urther progressof engineering will depend on continuous development of all forms of

construction developed of all forms of construction.

%olymer concrete composites were developed during '()*s in +.S..In I-I it is widely used for rehabilitation of structures. The

popularity gained by the materials is /ustified by its extraordinary highstrength, lower unit weight, total water impermeability and unmatched

chemical resistance.

#ngineers are trying to improve its 0uality, strength, etc.against adversecondition. $or satisfactory utili1ation of this alternative material, thevarious phases of examination to check its2

Technical feasibility

urability of processed concrete

#conomic feasibility

!ith the ongoing research being done to develop appropriate

technology and field trials to monitor the performance ad assessment ofeconomic feasibility, the use of this alternative material will become

more viable.

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ADMIXTURES USED IN CONCRETE:

dmixture is defined as the material other than cement water and

aggregates that is used as an ingredient of concrete and is added tobatch immediately before or during mixing. dditive is a material

which is added at the time of grinding cement clinker at the cementfactory.

s per the report of 4I committee "", admixtures have been

classified into 5 groups according to type of materials constituting theadmixture, or characteristic affect of the use. !hen 4I committee ""

submitted the report in '56, plastici1ers and super plastici1ers, as weknow them today, did not exist.

These days concrete is being used for wide varieties of purposes tomake it suitable in different conditions. In these conditions ordinary

concrete may fail to exhibit the re0uired 0uality performance ordurability. In such cases, admixture is used to modify the properties of

ordinary concrete so as to make it more suitable for any situation.

dmixtures have been traditionally used to improve the properties ofconcrete. There are two types of admixtures2 chemical admixtures and

mineral admixtures. #xamples of chemical admixtures are high rangewaterreducing admixtures such as super plastici1ers which constituted

a ma/or break through in the development of 7igh performanceconcrete 87%49.its use can drastically reduce the water cement ratio

8w:c9 from ).5 or higher to ).3 or low , while providing rheologicalcontrol of the concrete , given proper mixture proportioning and

materials selection.

The reduction in w:c yields denser paste matrix and strengthen pasteaggregate bonding on the micro structural level. ;ineral admixtures

such as silica fume, fly ash, slag, ricehusk, ash also provide benefits inconcrete.

The improved rheology and cohesiveness, lower heat of hydration,

lesser thermal shrinkage, and higher resistance to sulphate attackemerged over the years on the use of different minerals admixtures. It is

therefore true to say that the combined use of chemical and mineraladmixtures has resulted in a new generation of concrete called 7%4,

which was already within the construction industry.

POLYMER BONDING AGENTS:

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It is one of the well known facts that there will not be perfect bond

between the old concrete and the new one.


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ROLE OF FIBRES:

!hen the loads imposed on concrete approach that for failure crackswill propagate, sometimes rapidly= fibres in concrete provide a means

of arresting the crack growth. >einforcing steel bars in concrete havethe same beneficial effect because they act as long continuous fibres.

Short discontinuous fibres have the advantage, however, of beinguniformly mixed and dispersed throughout the concrete.

$ibres are added to a concrete mix which normally contains cement,water and fine coarse aggregate. mong the more common fibres used

steel, glass, asbestos and polypropylene.

ENVIRONMENTAL FACTORS:

>esistance of fibrereinforced concrete to environmental factors such as

frost action depends on the 0uality of the concrete. $ibres can beeffective, however in reducing frost damage because of their crack

arresting properties. 4are should be taken to ensure that an ade0uateamount of entrained air is incorporated in the mix additional resistance

to free1ing and salt corrosion.?ther environmental problems such as acid attack, sulphate attack and

alkaliaggregate reaction are generally not augmented by the presenceof fibres unless there is a chemical reaction between the fibre and the

concrete.

OBJECTIVE OF THE EXPERIMENT:

To experimentally study compressive, tensile and flexural strength oflatexmodified fibre reinforced concrete of ;6) grade.

nd these results are compared with conventional concrete of ;6)grade.

LITERATURE REVIEW:

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ttempts to increase 4ompressive strength of concrete have beensuccessful. @ut tensile strength and ductility not modified.

;odification of concrete with latex is the answer today with improvedductility.

Special applications are in the seismic areas and structures sub/ected todynamic loads.

Latex modified concrete improves durability of concrete.

Latex also reduces the permeability of concrete.

Latex modified mortar and concrete provide a good workability, water

retention over conventional cement mortar & concrete. Latex used here

is manufactured by $?S>?4 chemicals 8India9 pvt, Ltd under thechemical name -IT?@?-SBR.

In contrast to ordinary cement mortar and concrete which are apt to

cause bleeding and segregation, the resistance of latex modified mortar& concrete to bleeding and segregation is excellent in spite of their

larger flow ability characteristics. Setting time of latex modified mortar& concrete is delayed in some extent. In concrete the tensile & flexural

strengths are improved over a normal concrete but in compressivestrength there is no improvement.

MATERIALS USED:

The ingredients used in the test are as follows2

. 53 grade ordinary %ortland cement 8IS ""(''AB9 passingthrough IS') microns sieve.

". $ine aggregate passing through " mm sieve3. 4oarse aggregate passing ") mm sieve

6. Latex solution manufactured by $?S>?4 chemicals under the

brand name -itobond SBR.5. 4orrugated Steel fibres with aspect ratio of ).A

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MIXTURE PROPERTIES:

WORKABILITY:

Cenerally , latexmodified mortar and concrete provide a goodworkability over unmodified cement mortar and concrete .This is

mainly interpreted in terms of improved consistency due to the ballbearing action of polymer particles and entrained air and the dispersing

effect of surfactants in the latexes .This tendency is more significant atsmaller sandaggregate ratios at large unit cement content.

WATER RETENTION:

Latexmodified mortar and concrete have a markedly improve waterretention over unmodified cement mortar and concrete. The water

retention is dependant on the polymercement ratio.

The reasons for this can probably be explained in terms of thehydrophilic colloidal properties of latex themselves and the filling and

sealing effects of impermeable polymer films formed. ccordingly, asufficient amount of water re0uired for cement hydration is held in the

mortar:concrete, hence dry cure is preferable rather than wet or watercure. The water retention generally increases with rising polymer

cement ratio, and becomes nearly constant at a polymer cement ratio of5 to)D.Such excellent waterretention of the latex modified mortars is

most helpful to inhibit dryout phenomena in thin layer linings orcoatings on highly water E absorbable substrates such as dried cement

mortars.

BLEEDING AND SEGREGATION:

In contrast to unmodified cement mortar and concrete, which are apt to

cause bleeding and segregation, the resistance of latexmodified mortarand concrete to bleeding and segregation is excellent in spite of their

larger flow ability characteristics. This is due to the hydrophiliccolloidal properties of latexes themselves and the airentraining and

waterreducing effects of the surfactants contained in the latex.

SETTING BEHAVIOUR2

In general the setting of latexmodified mortar and concrete is delayedto some extent in the comparison with unmodified cement mortar and

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concrete, and this trend is dependant ion the polymer type and cementratio. The slower setting does not cause inconvenience in practical

applications. -atural rubber modified mortar 8->9 causes the mostdelay in setting. +sually, the reasons for the setting delay are the

surfactants such as alklylben1ene, sulfonates and caseinates containedin the latexes inhibit the hydration of cement. >heological studies on

polyvinyl acetate modified concrete is that the hydration of cement isinhibited by the adsorption of the surfactants on the binder surface.

STRENGTH:

The strength properties of the latexmodified mortar and concrete areinfluenced by various factors, which tend to interact with each other.

The main factors are the nature of materials used such as latexes,cement, aggregates and controlling factors for mix properties 8e.g.2

polymercement ratio, water cement ratio, bindervoids ratio, cutting

methods and testing methods etc9.

Latex Emodified mortar and concrete show a noticeable increase in thetensile and flexural strengths but no improvement in the compressive

strengths. Thus in this investigation steel fibre is added in addition tolatex to increase certain amount of compressive strength and to

improve crack resistance.

EFFECTS OF CONTROL FACTORS FOR MIX

PROPORTIONS:

The binder of latexmodified mortar and concrete consists of polymer

latex and inorganic cement, and their strength is developed as a resultof an interaction between them. Low polymercement ratio of 5 D or

less also not effective because of little improvement in the strength.4onse0uently the polymer cement ratio range of 5 to ")D is used in

practice. ;ost latexmodified mortars and concretes cured underfavorable conditions have effective strength properties at polymer

cement ratios up to ")D and the strength may be reduced at polymercement ratios exceeding ")D.

EFFECTS OF SAND-CEMENT RATIO:

!hen the sandcement ratio increases, the flexural and compressive

strengths of latexmodified mortars are remarkably reduced, and the

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effect of the polymercement ratio on the strengths gradually becomessmaller.

EFFECTS OF CURING CONDITIONS:

$avorable curing condition re0uirements for latexmodified mortar andconcrete differ from those for ordinary cement mortar and concrete,

because their binder consists of two ordinary cement phases of latexand hydraulic cement with different properties. ?ptimum strength in

the cement phase is developed under wet conditions such as waterimmersion and high humidifies , where strength development in the

latex phase is attained under dry conditions .It is evident that optimumstrength in most latex modified mortars and concrete is obtained by

achieving the reasonable extent of cement hydration under wetconditions at early ages, followed by dry conditions , such curingconditions are most suitable sensitive for the mortars than for the

concretes because of a difference in the retention due to their specimensi1es.

RELATION BETWEEN SURFACE HARDNESS AND

COMPRESSIVE STRENGTH:

The surface hardness of latexmodified systems is generally improvedto some extent over ordinary cement systems, depending on the

polymer type and the polymercement ratio. definite correlationbetween the surface hardness and compressive strength of most latex

modified systems is recogni1ed.

SRESS-STRAIN RELATIONSHIP MODULUS OF ELASTICITY

AND DUCTILITY:

;ost latexmodified mortars and concretes provide a higher

deformation, ductility and elasticity than ordinary cement mortar andconcrete, their magnitude depending on polymer type and polymer

cement ratio. The maximum compressive strain at failure increaseswith rising polymercement ratio, even though there is no pronounced

change in the modulus of elasticity in compression. The maximumcompressive strain at a polymercement ratio of ")D increases to " to 3

times that of unmodified mortar.The polymercement ratio is raised, the modulus of elasticity in tension

decreases, and the elongation increase and is " to 3 times grater thanthat on unmodified concrete. This is explained by considering that the

polymer films formed in the concrete effectively halt propagatingmicro cracks through their high tensile strength and elongation. The

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modulus of elasticity tends o decrease with the rise in the polymercement ratio.

SHRINKAGE CREEP AND THERMAL EXPANSION:

The drying shrinkage increases with additional dry curing period , andbecomes nearly constant at a dry curing period of "A days regardless to

polymer type and polymer cement ratio generally , the "A thday dryingshrinkage tends to decrease with increasing polymer cement ratio

%F4 , -> and 4hloroprene rubber84>9 modified mortars have a largeshrinkage compared to that of unmodified mortars evaporation of the

large amount of water absorbed in polymer phase due to the low waterresistance of the polyvinyl acetate itself.

WATER PROOFNESS AND WATER RESISTANCE:

Latexmodified mortars and concrete have a structure in which the

large pores can be filled with polymer with continuous polymer films.These features are referred in reduced water absorption water

permeability and water vapour transmission as a result= latexmodifiedmortars and concrete have improved water proofness over ordinary

mortars and concrete.

ADHESION OR BOND STRENGTH:

very useful accepts of latexmodified mortars and concrete is theirimproved adhesion or bond strength to various substrates compared to

conventional mortars and concrete. The development of adhesion isattributed to the high adhesion of polymers. The adhesion is usually

affected by polymercement ratio and the properties of the substratesused. The data of adhesion often shows considerable scatter, and

many vary depending on the testing methods, service conditions orporosity of substrates. The adhesion of most latexmodified mortars

tend to increase with rising polymer cement ratio= although for a fewtypes there is optimum polymercement ratios.

The mix proportions also influence the adhesion, namely, the strengthof the mortar substrates in 2" mix substrates through rather than

through the interface. 7owever it appears that the adhesion than theflexural strength


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IMPACT RESISTANCE:

Latexmodified mortars or concrete has an excellent impact resistancein compression with conventional mortars and concrete this is because

of polymer they have high impact resistance. The impact resistancegenerally increase with rising polymercement ratio. The data of the

impact resistance vary markedly between the testing methods .theimpact resistance of the latexmodified mortars with elastomers is

superior to the mortars with thermo plastic resins. The impactresistance S@> Emodified mortars with polymer cement ratio of ")D is

about ) times greater than that of the unmodified mortars.

CHEMICAL RESISTANCE:

;ost latex modified mortars and concrete are attacked by inorganic ororganic acid and sulphates since they contain hydrated cement that is

no Eresistance to these chemical resistance is generally rated as good tofats and oils, but to organic solvents.

PROPERTIES OF FIBRES:

4oncrete lends itself to a variety of innovative designs as a result of itsmany desirable properties. -ot only can it be cast in diverse shapes= but

it also posse*s high compressive strength, stiffness, low thermal andelectrical conductivity and low combustibility and toxicity.

Two characteristics, however, have limited its use it is brittle and weaktension. >ecently, however the development of fibrereinforced

composites in the plastics and aerospace fields has provided a technicalbasis for improving these deficiencies.

PHYSICAL AND MECHANICAL PROPERTIES OF SELECTED

FIBRES

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TYPE

OF

FIBRE

DIAMETER

!"

SPECIFIC

GRAVITY

FAILURE

STRAIN#

MODULUDS

OF

ELASTICITY

GP$

TENSILE

STRENGTH

GP$

S%&&' 55)) B.A 36 ")) 3

G'$(( '5 ".( "3.5 A) "3

COMPOSITE PROPERTIES:

$ibres can improve the toughness, the flexural strength, or and arechosen on the basis of their availability, cost and fibre properties.

$ibres also generally reduce creep strain, which is defined as the time

dependant deformation of concrete under a constant stress. $orinstance, steelfibrereinforced concrete can have tensile creep values

5) to () percent of those for normal concrete. 4ompressive creepvalues, however, may be only ) to ") D of those for normal

concrete.Shrinkage of concrete, which is caused by the withdrawal of water

from concrete during drying, is lessened by fibres. Shrinkage of glassfibrereinforced concrete is decreased by up to 35D with the addition

of .5D y volume of fibres.?ther properties of concrete, such as compressive strength and

modulus of elasticity, are not included in the tables since they areaffected to a much lesser degree by the presence of fibres.

Innovations in engineering design, which often establish the need forfew building materials, have made fibrereinforced cements very

popular. The possibility of increased tensile strength and impactresistance offers potential reactions in the weight and thickness of

building components and should also cut down resulting from shipping

and handling.lthough ST; 466)B6a describes the use of asbestoscement andrelated products, there are, at this, no general ST; standards for

fibrereinforced cement, cement, mortar and concrete. +ntil thesestandards become available, it will be necessary to rely on the

experience and /udgment of both the designer and the fibremanufacturer.

EXPERIMENTAL INVESTIGATIONS

INTRODUCTION

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The aim of this experimental work is to compare the strength ofconventional concrete with concrete with steel fibres and also to

compare the first crack load, ultimate load, and crack pattern anddeflection response of plain concrete beam and with latexmodified

fibre reinforced concrete beam. Test for finding out the compressivestrength, tensile strength, flexural strength, impact strength was

conducted. In order to find out the compressive strength, concretecubes having a si1e of 5)x5)x5)mm were cast and tested using

+T;. $or finding out the spilt tensile strength concrete cylindershaving 5) mm diameter and 3)) mm height were cast and tested with

+T; with the diameter hori1ontal. In order to find out the flexuralstrength concrete prism having si1e ))x))xB5)mm were casted and

tested in +T;

MATERIALS USED AND THEIR SPECIFICATIONS:The materials used and their specifications are as follows

CEMENT:

The type of cement used was ordinary %ortland cement and its specificgravity is 3.5. The cement was confirming to IS "(''B(

FINE AGGREGATE:

Locally available sand without debris was used, tests were conducted

as per IS"3A( 8%>T I9.Specific gravity of fine aggregate is ".(6

COARSE AGGREGATE:

4rushed granite stone aggregates of maximum si1e of ") mm was used

tests were conducted as per IS "3A(8part III9 of '(3.Specific gravity of coarse aggregate is ".('

WATER:

s per IS 65("))) recommendations, potable water was used for

mixing of concreteCONCRETE MIX PROPOTION:

4oncrete was designed as per IS )"("'A". The target strength of themix was 6)-:mmG of cube at the age of "A days. The mix adopted is

1: 0)*+: ,),by weight with water cement ratio of ).35

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STEEL FIBRES:

The corrugated steel fibres were used with aspect ratio () 83(:).(9Length of the fibre 3( mm

Thickness of fibre ).(mmThe tensile strength of fibre is in the range of 3 Cpa

THE MIX:

Latex added is 5D of weight of cementSteel .5D of volume of concrete

CASTING AND CURING OF SPECIMENS:

The materials were weighed carefully using the balance for the ordinaryconcrete fine aggregate and cement were weighed and mixed thoroughly, thecoarse aggregate was then added and mixed with above. Steel fibres were

then added following latex and water are added and mixed thoroughly to geta good mix.

$or preparing the specimen for determining the compressive, tensile,

flexural strength permanent steel moulds of standard si1e 5)x5)x5)mm,5)mm diameter 3)) mm height , 5)x5)xB5) mm respectively.

The sides and bottom of all the moulds were properly oiled for easedemoulding. Then the fresh was filled layer by layer and then compaction

was done by table vibrator.

@efore mixing the concrete the mould and other materials were kept ready.The fresh concrete was filled in the mould. 4are should be taken to see that

the concrete was compacted perfectly. The compaction was carried outmanually and the top surface was leveled and finished. ll the moulds were

demoulded "6 hrs after casting, cured in water for another "B days. Theywere tested on "Athday as per IS 65('BA.

TESTING OF SPECIMENS

CUBE COMPRESION TEST:

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The test was conducted as per IS 5('5'. the cube of standard si1e5)x5)x5)mm were uses to find the compressive strength of concrete

specimens were placed on the bearing surface of +T;, of capacity )))tonnes without eccentricity and a uniform of loading of 6) kg per cmH" per

minute was applied till the failure of the cube at failure, the failure of themaximum load was noted and the compressive strength was calculated.

4ube compressive strength 8cc9 in ;pa J %f:b!here %fJ failure load 8-9bJ bearing area of the cube 8mmG9.

SPLIT TENSILE STRENGTH OF CONCRETE:

This test was conducted as per IS 5A('B). The cylinders of standard si1e

5)mm diameter and 3)) mm height was placed on the +T;, with thediameter hori1ontal at the top and bottom two strips of wood where placedto avoid the crushing of concrete specimen at the points where the bearing

surface of the compression testing machine and the cylinder specimenmeets. The maximum load was noted down.

The spilt tensile strength 8Tsp9 J "%:Kdl 8;pa9!here % is maximum load 8-9

d J measured diameter of specimen 8mm9l J measured length of specimen 8mm9

FLEXTURAL STRENTH TEST2

This test is conducted as per IS5('5'.prisms of standard si1e

5)x5)xB5)mm were used. Tests were carried in +T; the loads wereapplied at ')mm from either ends. +niform loading was applied and

maximum loading was noted.The modulus of rupture was calculated

The modulus of rupture 8fb9 J3%a:bdG!here % J load 8-9

dJdepth of the prism mmbJ breath mmaJ distance between support and the point load

DISCUSSIONS AND COMPARSION OF TEST RESULTS

COMPARSION OF COMPERSSIVE STRENGTH:

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%ercentage

of $ibre

by weight

of cement

%ercentage

of latex by

volume of

concrete

4ompressive

strength

3days

8-:mmG9

4ompressive

strength

B days

8-:mmG9

4ompressive

strength

"A days

8-:mmG9

%ercentage

increase in

3 days

%ercentage

increase in

B days

%erc

incr

"A d

) ) "3 3.6 5B.5 BA.5

%ercentage

of $ibre

%ercentage

of latex by

volume ofconcrete

4ompressive

strength

3days8-:mmG9

4ompressive

strength

B days8-:mmG9

4ompressive

strength

"A days8-:mmG9

%ercentage

increase in

3 days

%ercentage

increase in

B days

%erc

incr

"A d

) .5 "3.33 36."3 5A A5

%ercentageof $ibre

%ercentageof latex by

volume of

concrete

4ompressivestrength

3days

8-:mmG9

4ompressivestrength

B days

8-:mmG9

4ompressivestrength

"A days

8-:mmG9

%ercentageincrease in

3 days

%ercentageincrease in

B days

%ercincr

"A d

5 .5 "3.B( 36.AA 5' AB

COMPARSION OF SPLIT TENSILE STRENGTH

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%ercentage

of $ibre

%ercentage

of latex by

volume of

concrete

4ompressive

strength

B days

8-:mmG9

4ompressive

strength

"A days

8-:mmG9

%ercentage

increase in

B days

%ercentage

increase in

"A days

) ) 3.))

%ercentage

of $ibre

%ercentage

of latex by

volume ofconcrete

4ompressive

strength

B days8-:mmG9

4ompressive

strength

"A days8-:mmG9

%ercentage

increase in

B days

%ercentage

increase in

"A days

) 5 3.35

%ercentage

of $ibre

%ercentage

of latex by

volume of

concrete

4ompressive

strength

B days

8-:mmG9

4ompressive

strength

"A days

8-:mmG9

%ercentage

increase in

B days

%ercentage

increase in

"A days

.5 5 3.5)

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CONCRETE DESIGN MIX

INTRODUCTION:

4oncrete ;ix esign is a process by which we determine the relativeproportion of the various materials of concrete with an aim to achieve a

certain minimum strength and durability, as economically as possible.@asically two factors are involved in concrete design mix. !e have to

achieve a certain minimum strength, and we have to do it aseconomically as possible. Two kinds of costs are involved in the

making of concrete= namely cost of materials and cost of labor. Thelabor cost, which comprises of formwork, batching, mixing,

transporting and curing is nearly the same for good concrete as wellbad concrete. mong the material costs in conventional concrete, thecost of cement, which binds the aggregate together, is far higher than

the costs of the other ingredients. Therefore the mix design aims atselecting as little cement as possible, consistent with the re0uirement of

strength and durability.The ingredients of concrete can be broadly classified into 89 aggregate

and 8"9 paste. The paste lubricates the concrete and is responsible forits workability. The lubricating effect of the paste is directly

proportional to the dilution of the paste. @ut more dilute the paste, lessstrong it will be. It is be noted that the strength of concrete is limited by

the strength of the paste, because the mineral aggregate, with rareexceptions are for stronger than the paste, because compound. lso the

permeability of concrete is determined by the 0uality and continuity ofthe paste, since little water flows through the aggregate either under

capillarity. $urther, the predominant contribution to drying shrinkage ofconcrete is that of paste.

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DETERMINATION OF SPECIFIC GRAVITY FOR FINE

AGGREGATE2

This test is used to determine the specific gravity of the sand. Specific gravity test is conducted by using @alance &

%yconometer. The pyconometer is cleaned for presence of dust , or moisture

inside and its empty weight is taken small 0uantity of dry sand is put inside the pyconometer so

as to fill about one fourth of the pyconometer and the weight of

pyconometer with sand is taken The pyconometer is then filled, completely with distilled water.

ny entrapped air shall be eliminated by rotating the pyconometer in

its side The pyconometer shall be topped up with distilled water to

remove any forth from the surface, dried on the outside and weighed. The pyconometer is refilled with distilled water to the same

level as before, dried on the outside and weighed.

?@S#>FTI?-S - 4L4+L?TI?-S=

$or ))D riverbed sand2!eight of empty pyconometer 8w9 J

!eight of pyconometer and dry sand 8w"9 J!eight of pyconometer, sand and water 8w39 J

!eight pyconometer and water 8w69 JSpecific gravity, C J 8w"w9: 8w"w9

8w3w"9M

Documents

14532154 Experimental Study of Strenth of Latex Modified Fibre Reinforced Concrete