test on aggregates

7/24/2019 TEST ON AGGREGATES

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EXP NO 3 TESTS ON AGGREGATES 1

DATE: 12 Feb 2015

AIM:

To determine the following properties of coarse and fine aggregates

1. Specific Gravity2. Bulk Density and % of voids

. !ater "#sorption $apacity

. &lakiness 'nde(). *longation 'nde(

+. "ngularity ,um#er

-. Bulking of Sand. /article Si0e Distri#utionGradation

TEST-1 SPECIFIC GRAVITY

Specific Gravity of aggregates is often considered as a measure of strength and dura#ilityuality

of aggregates. 't also helps to identify the type of stone.

Specific Gravity is the ratio of unit weight of solids to unit weight of water at

3$. B'S 2+ 4/art5 pertains to the procedure of test for Specific Gravity.

Appara!":

1. /ycnometer

2. !eighing Balance. 6ven

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Pr#$e%!re:

1. " sample of saturated surface dry fine aggregate of weight 4$5 is taken and filled in the

pycnometer roughly a#out 2rdof the volume.2. Distilled water shall #e poured into it until it is full.

. !ipe out the e(ternal surface of pycnometer and weigh it 4"5. Transfer the contents of the pycnometer into a tray and the sample is to #e oven dried for

2 hours at 17781173$). 9efill the pycnometer with distilled water to the same level and weigh it 4B5.

+. The oven8dried sample is weighed 4D5.

Same procedure shall #e followed for $oarse "ggregates also.

The Specific Gravity is calculated as S :D

C(AB)

Ob"er&a'#(":

CONTENT FINE AGGREGATE COARSE AGGREGATE

A )*+ 27+- 21

, )*+ 1)21 1)21

C )*+ ) ;;7.)

D )*+ -; ;27

Spe$''$ *ra&'. /

D

C(AB)100 25 2

TEST 2 4ATER A,SORPTION

!ater "#sorption of aggregates are a measure of strength< as more water a#sorption tends to

relate to more porosity of aggregates. /orous aggregates are often unsuita#le< unless they are

found accepta#le in hardness< impact test.

!ater "#sorption is e(pressed in percentage as water a#sor#ed #y aggregates to the dry weight

of aggregates

B'S 2+ 4/art 5 pertains to the procedure of test for !ater "#sorption.

Appara!":

1. $ontainer

2 !eighing Balance

Pr#$e%!re:

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1. The sample of minimum 2777g is taken and shall #e immersed in water< "fter immersion hours at

temperature 2-?)@$. Then the aggregates shall #e drained out of water and shall #e surface dried #y a cloth.

the weight shall #e recorded as ". The aggregates shall #e placed in an oven at a temperature of 177 $ to 117 $ ). The aggregate is taken out from the oven after 2 hours< cooled and weight shall #e

recorded as B

!ater a#sorption of fine aggregate is calculated as

!ater a#sorption !" % :ABB 100

Ob"er&a'#(":

FINE AGGREGEATE COARSE AGGREGATE

A )*+ )77 1777

, )* ;;7.)

4A )+ 352 06

TEST 3 - ,789 DENSITY AND VOIDS

Bulk density of aggregates is the mass of aggregates reuired to fill the container of a unit

volume after aggregates are #atched #ased on volume.

't depends on the packing of aggregate i.e. *ither##"e. pa$;e% a**re*ae"or ape # a**re*ae". B'S 2+ 4/art5 pertains to the procedure of Bulk Density test

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Appara!":

1. $ylindrical Aessel $ontainer

2. Tamping 9od. !eighing Balance

Pr#$e%!re:

1. The cylindrical vessel shall #e filled with aggregates in three layers and tamp it 2) times

using tamping rod.2. &inally fill aggregate in the metal measure to over8flowing and tamp it 2) times.

. The weight of the compacted aggregate in the measure shall #e recorded as "4kg5

. To measure the volume of the vessel< water of Specific Gravity wshall #e poured in the

vessel and weight shall #e recorded as B4kg5

Bulk density shall #e calculated as :

A

B

w

/ercentage of Aoids 4%Aoids5 :S

w

S100

Ob"er&a'#(":

FINE AGGREGATE COARSE AGGREGATE

4e'*> # Ve""e )*+ 211 2;

4e'*> # C#=pa$e% a**re*ae # 4aer


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V#'%" 2636 30

TEST - ANG78ARITY N7M,ER

"ngularity ,um#er Test is carried out for determining shape of the aggregates. Based uponshape the aggregates may #e classified as 9ounded< "ngular or &laky. "ngular particles possess

well defined edges formed at the intersection of roughly planer faces and are commonly formed

in aggregates prepared #y crushing of rocks.

"ngularity is the a#sence of rounding of particles of an aggregate. This test is performed to

determine the angularity num#er i.e. the a#sence of roundedness or the degree of angularity of

the aggregate specimen.

The usual shapes of the particles areC

1. 9ounded 4river gravel52. &laky 4laminated rock5. *longated

. "ngular 4crushed rock5

"ngularity num#er of an aggregate is the amount 4to the higher whole num#er5 #y which the

percentage of voids in it after compacting in a prescri#ed manner e(ceeds . where< 33E is the

percentage of volume of voids< in a perfectly rounded aggregate. BE is the percentage of

volume of solids in a perfectly rounded aggregate

B'S 2+ 4/art 15 pertains to the procedure of Test for "ngularity ,um#er

Pr#$e%!re:

1. The "ngularity ,um#er can #e calculated from results of Specific Gravity and Bulk

Density Tests.2. The procedure is similar to that of those tests e(cept that the aggregates to #e used shall

#e retained #etween the following sievesF

278mm and 1+8mm

1+8mm and 12.)8mm

12.)8mm and178mm17mm and +.8mm

+.8mm and .-)8mm

"ngularity ,um#er is calculated as ", : B -100A

BGs

Ob"er&a'#(":

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!eight of compacted aggregate< " 4g5 +)+

!eight of water< B 4g5 2;);

Specific Gravity of the aggregate< S 2.+

A(*!ar'. (!=ber 30

TEST 5 - F8A9INESS INDEX E8ONGATION INDEX OF COARSE AGGREGATES

&lakiness 'nde( is the percentage #y weight of particles in it< whose least dimension is less than

7.+ times of its mean dimension. 'n a similar way *longation 'nde( is the percentage #y weight

of particles in it< whose largest dimension 4i.e. length5 is greater than 1. times its mean

dimension.

ean dimension is the average of two sieves in which the aggregates have retained.

&laky and elongated particles may have adverse effects on concrete and #ituminous mi(. &or

instance< flaky and elongated particles tend to lower the worka#ility of concrete mi( which may

impair the long8term dura#ility. &or #ituminous mi(< flaky particles are lia#le to #reak up and

disintegrate during heavy traffic loads.

B'S 2+ 4/art 15 pertains to the procedure of &lakiness and *longation 'nde(. The test

performed for aggregates in si0es of 1+mm 8 27mm.

Appara!":

1. Thickness Gauge2. Hength Gauge

. !eighing achine

. 'S Sieves 1+m< 27mm

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Thickness Gauge for &lakiness 'nde(

Hength Gauge for *longation inde(

Pr#$e%!re:

1. The sample is taken from the lot and sieved through the sieves. The retained aggregates

are selected and out of it minimum f 277 pieces is taken and weighed 4!5.

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2. 'n order to separate flaky materials< each fraction is then gauged individually for

thickness on a thickness gauge which is provided in a#ove figure.

. The total amount of flaky material passed #y the thickness gauge is weighed 4&5 to an

accuracy of 7.1% of the weight of sample.

Similar procedure is carried out for *longation 'nde(< where a length gauge is used instead of a

thickness gauge. Similarly< total amount of elongated material ,6T passing through the length

gauge are weighed 4*5.

&lakiness 'nde( 4%5 :F

W100

*longation 'nde( 4%5 :E

W100

TEST F8A9INESS INDEX E8ONGATION INDEX

Thickness Hength Gauge 17.mm 2.mm

! 4g5 1-7+ 1-7+

& 4g5 7+ 8

* 4g5 8 )7+

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1B6 26

TEST - ,789ING OF SAND

The volume increase of fine aggregate due to presence of moisture content is known as #ulking.

&ine sand #ulks more as compared to coarse sand. *(tremely fine sand particularly the

manufactured fine aggregate #ulks as much as a#out 7%.

&ine aggregate do not show any #ulking when it is completely dry or completely saturated.

The moisture present in aggregate forms a film around each particle. These films of moisture

e(ert a force< known as "!ra$e e("'#( on each particle. Due to this surface tension each

particles gets away from each other. Because of this no direct contact is possi#le among

individual particles and this causes #ulking of the volume.

Bulking of aggregate is dependent upon two factors#%:

Pr#$e%!re:

1. &ill the measuring vessel with loose sand and measure the height 4h5

2. 9emove the sand and fill water a#ove the sand level. Top the vessel with sand and let it to inundate for some time. 9ecord the reading as 4y5

,!;'(* # Sa(% )+ / ( hy1)100

> )==+ 12

. )==+ 12

,!;'(* # Sa(%)+ 323

TEST B- PARTIC8E SIE DISTRI,7TION )S'e&e A(a."'"+

The sieve analysis or the gradation test determines the distri#ution of aggregate particles< #y si0e

test on aggregates

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