Lecture 1- Aggregates

7/23/2019 Lecture 1- Aggregates

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AGGREGATES

Dr. J. Berlin P. Juanzon CE, MBA,MSCM



AGGREGATES

Aggregate – is a combination ofsand, gravel, crushed stone, slag,

or other material of mineralcomposition, used in combinationwith a binding medium to form

such materials as bituminous andPortland cement concrete,mortar, and plaster, or alone, asin railroad ballast, lter beds, andvarious manufacturin rocesses.



The aggregate occupies ~707!" ofthe volume of concrete, so its #ualit$

is of great importance.

Aggregates ma$ a%ect the following

properties of concrete& – 'trength

– (urabilit$

– 'tructural Performance – )conom$



Aggregates have * main functions inconcrete&

+ To provide a mass of particles which aresuitable to resist the action of appliedloads - show better durabilit$ thancement paste alone.

To provide a relativel$ cheap ller forthe cementing material.

* To reduce volume changes resulting

from setting - hardening process -from moisture changes during dr$ing.



The properties of concrete area%ected b$ the properties of

aggregate&+. The mineral character of aggregate

a%ects the strength, durabilit$, elasticit$of concrete.

. The surface characteristics of aggregatea%ects the wor/abilit$ of fresh mass -the bond between the aggregate -

cement paste in hardened concrete. f itis rough, wor/abilit$ decreases - bondincreases.

*. The grading of aggregate a%ects the

wor/abilit$, densit$ - econom$.



2igher aggregate amount3unitvolume of concrete

– 4esults in less volume changes duringsetting - hardening or moisturechanges. 5increase in volume stabilit$

– ncrease in strength - durabilit$

– (ecrease in cost

t is a common practice to use asmuch aggregate as possible inconcrete



2owever, all aggregates are notinert&

– The ph$sical action& swelling -shrin/age

– The chemical action& al/aliagg.

4eaction – The thermal action& e6pansion -

contraction

i/e the other ingredients ofconcrete, aggregates must also bechosen with certain care to end up

with a satisfactor$ concrete.



CLASSIFICATION OFAGGREGATES

According to 'ource&

+. 8atural aggregate& 8ative deposits with

no change in their natural state otherthan washing, crushing - grading. 5sand,gravel, crush stone

. Articial aggregates& The$ are obtained

either as a b$product or b$ a specialmanufacturing process such as heating.5blast furnace slag, e6panded perlite



According to Petrological9haracteristics&

+. gneous roc/s& are formed b$

solidication of molten lava. 5granite. 'edimentar$ roc/s& are obtained b$

deposition of weathered - transportedpree6isting roc/s or solutions.

5limestone*. :etamorphic roc/s& are formed under

high heat - pressure alteration of eitherigneous - sedimentar$ roc/s 5marble.



According to ;nit <eight&+. 2eav$ weight agg.& 2ematite, :agnetite

'pecic =ravit$, =s > .?

. 8ormal weight agg.&=ravel, sand, crushedstone .? @ =s @ .1

*. ight weight agg.&)6panded perlite,burned cla$ =s @ .1



Normal-Weight

Aggregate:ost common aggregates

'and =ravel

9rushed stone

Produce normal-weight concrete 2200 to 2400 kg/m3

ASTM C 33





Lightweight Aggregate(2)

Pumice

'coria

Perlite ermiculite

(iatomite

Produce lightweight insulating concrete—

250 to 1450 kg/m3

ASTM C 330



Hea!weightAggregate

Barite

imonite

:agnetite

lmenite

ASTM C 637, C 638 (Radiation Shielding)

Produce high-density concrete up to 400 kg/m3

2ematite

ron

'teel punchings orshot



. According to 'iCe&+. Dine aggregate& d E ! mm

. 9oarse aggregate& d > ! mm

. Aggregates containing a whole rangeof particles are named as FallinG or

FpitrunG aggregates.



Fi"e Aggregate

'and and3orcrushed stone

@ ! mm

D.A. contentusuall$ *!" to1!" b$ mass orvolume of totalaggregate



Coar#e Aggregate

=ravel andcrushedstone

≥ ! mm

t$picall$between H.!and *7.! mm



Aggregate Chara$teri#ti$# a"%Te#t#Characteristic Test

Abrasion resistanceASTM C 131 (AASHTO T 96), ASTM C 535,ASTM C 779

Freeze-tha resistanceASTM C 666 (AASHTO T 161), ASTM C 6!",AASHTO T 1#3

S$%&ate resistance ASTM C !! (AASHTO T 1#')

artic%e shae an*s$r&ace te+t$re

ASTM C "95, ASTM 339!

ra*in.ASTM C 117 (AASHTO T 11), ASTM C 136

(AASHTO T "7)Fine a..re.ate*e.ra*ation

ASTM C 1137

/oi* content ASTM C 1"5" (AASHTO T 3#')

0$% *ensit2 ASTM C "9 (AASHTO T 19)

h i i %



Aggregate Chara$teri#ti$# a"%Te#t#

Characteristic Test

e%ati4e *ensit2 ASTM C 1"7 (AASHTO T !5)&ine a..re.ateASTM C 1"! (AASHTO T !')coarse a..re.ate

Absortion an* s$r&aceoist$re

ASTM C 7#, ASTM C 1"7 (AASHTO T !5), ASTMC 1"! (AASHTO T !'), ASTM C 566 (AASHTO T"55)

Stren.thASTM C 39 (AASHTO T ""), ASTM C 7!(AASHTO T 97)

e& o& constit$ents ASTM C 1"5, ASTM C "9'

A..re.ate constit$ents

ASTM C '# (AASHTO T "1), ASTM C !7

(AASHTO T 71), ASTM C 117 (AASHTO T 11),ASTM C 1"3 (AASHTO T 113), ASTM C 1'"(AASHTO T 11"), ASTM C "95

A%a%i esistanceASTM C ""7, ASTM C "!9, ASTM C "95, ASTM C3'", ASTM C 5!6, ASTM C 1"6# (AASHTO T 3#3),

ASTM C 1"93



SA&'LING

Tests in the lab is carried out on thesamples. 'o, certain precautions in

obtaining a sample must be ta/en toobtain Frepresentative sampleG.

The main sample is made up of portions

drawn from di%erent points. Theminimum number of portions,increment, is +0 - the$ should add upto a weight not less than&



Max. ParticleSize

Min. Weight of Sample(g!

! 25 mm 50

25-5 mm 25

" 5 mm 13

I (etails are provided in A'T: ( 7! - T'

707



&etho%# o re%$i"g the amo"t o #am*le+

1) Quartering:. :i6 the eld sample over three times on a level

surface.. 'hovel the sample to a conical shape.

. Press the ape6 - Jatten the conical shape.. (ivide them into four e#ual #uarters.

. (iscard two diagonall$ opposite #uarters - usethe remainder.

. f this remainder is still too large follow the samepath.

'ide 'ide Top Top



2) Splitting:. ;se the Fsample splitterG to divide

the aggregate sample into two.. 'ample splitter is a bo6 with an

even K of chutes alternatel$

discharging to two sides.. The width of each chute should be

greater than +.! times the siCe of

the largest aggregate siCe.. f the remainder is still too large

follow the same path.



'ARTICLE SHA'E , SRFACE



'ARTICLE SHA'E , SRFACETE.TRE

n addition to petrological character,the e6ternal characteristics, i.e. Theshape - surface te6ture of aggregatesare of importance.

Particle 'hape 4ounded& 9ompletel$ water worn -

full$ shaped b$ attrition. 54iver

=ravel

rregular& Partl$ shaped b$ attrition soit contains some rounded edges.5and =ravel



Angular& 2as sharp corners, show littleevidence of wear. 59rushed 'tone

Dla/$& Thic/ness is relativel$ small withrespect to two other dimensions.

5aminated 4oc/s

)longated& 2ave lengths considerabl$

larger than two other dimensions

wt



DA T

)L8=AT)(

4L;8A8=;A





'urface Te6ture This a%ects the bond to the cement

paste - also inJuences the waterdemand of the mi6.

Smooth: Bond b3w cement paste - agg iswea/.

Rough& Bond b3w cement paste - agg. is

strong.

'urface te6ture is not a ver$important propert$ from compressivestrength point of view but agg.

2aving rough surface te6ture



':LLT2 4L;=2



Gra%i"g o Aggregate#

/Gra%i"g i# the *arti$le-#i0e%i#tritio" o a" aggregate a#%etermi"e% ! a #iee a"al!#i# #i"gwire me#h #iee# with #are

o*e"i"g#3

AST& C 44

Fi"e aggregate/5 #ta"%ar% #iee# witho*e"i"g# rom 167 8m to 936 mm

Coar#e aggregate/14 #iee# witho*e"i"g# rom 131: mm to 177 mm



"S #$%

125 mm

#0 mm3 mm

31$5 mm

1 mm

8 mm4 mm

2 mm

1 mm

0$5 mm0$25 mm

AS"M C &&

125 mm

100 mm

#0 mm

%5 mm &3'(3 mm

50 mm &2'(

3%$5 mm &1-1/2'(

25 mm &1'(12$5 mm &1/2'(

#$5 mm &3/8'(

4$%5 mm &)4(

2$38 mm &)8(1$1# mm &)1(

0$5#5 mm &)30(

0$2#% mm &)50(

0$14# mm &)100(



The material is sieved through aseries of sieves that are placed oneabove the other in order of siCe withthe largest sieve at the top.

(r$ agg. is sieved to prevent lumps.

IIIII

Agg.

K1K?K+M

K*0K!0

K+00Pa

n

'ieve

sha/er

ateral - ertical

motion





The particle siCe distribution in anaggregate sample is /nown asFgradationG.

'trength development of concretedepends on degree of compaction -wor/abilit$ together with man$ otherfactors. 'o, a satisfactor$ concrete should

be compacted to ma6 densit$ with areasonable wor/.

Ln the other hand, in good concrete all

aggregate particles must be covered b$



The grading of aggregate must be sothat the wor/abilit$, densit$ - volume

stabilit$ of concrete ma$ not beadversel$ a%ected b$ it.

Dine Particles * higher cost +oarse Particles * less worka,ility

reasona,le com,ination o. .ine coarseaggregate must ,e used$ his can ,e

epressed ,y maimum density or minimum

oids concept$



Re%$tio" o

;oi%#

Fa$tor# A<e$ti"g a



Fa$tor# A<e$ti"g a=e#ire% Gra%i"g

1) Surface area of the Aggregate The lower the surface area, thelesser is the paste re#uirement.

2) Relative Volume of Agg. in Concrete2igher volume of agg.&

*economical

*higher strength higher olume sta,ility

*less worka,ility N



3) Workability & The ease with which aconcrete mi6ture can be mi6ed,transported, placed in the form -

compacted without an$ segregation.<or/abilit$ increases as the amount ofpaste b3w ne agg. part increases. t alsoincreases as the amount of mortar b3w

coarse agg. particles increases.

) Segregation& 'eperation of the particleswith di%erent siCes - specic gravities.

The re#uirements of wor/abilit$ andabsence of segregation tend to opposeeach other. Thus, these two factors areinterrelated. The maOor of these iswor/abilit$ which, in turn, a%ects most of

=etermi"atio" o the Gra%i"g o



=etermi"atio" o the Gra%i"g oAggregate

There are two di%erent methods fordetermining the agg. grading&

Dineness :odulus 5D: =ranulometr$

The grading of the particles in an agg.sample is performed b$ Fsieve

anal$sisG. The sieve anal$sis isconducted b$ the use of Fstandard testsievesG. Test sieves have s#uareopenings - their designation

correspond to the siCes of those

Di : d l 5D:



+ Dineness :odulus 5D:&. D: is a single gure which is the sum of

cumulative " retained on a series of sieveshaving a clear opening half that of the preceeding

one. ;suall$ determined for ne agg.

Dor Dine Agg.*)4 )8 )1 )30 )50 )100'practical limit)*+&.- or +oarse gg$*ine set3/863/461 7636

'practical limit).+.$- he o. the miture o. two or more agg$ is the weighted

aerage o. the o. that two more agg$

D: 9 &: cumulatie retained on each siee(

+00

) A !00 l f Di A i d



)6&A !00gr sample of a Dine Agg. was sieved.(etermine D:Q

Pan is not included. Lnl$ standard sieves are included, if we were

given K+0 sieve $ou should not use that in

Sie/eAmount 0etaine1

on (gr!Amount 0etaine1

on (2!

2 Cumulati/e0etaine1 on

&34 $ 0 056 &$

5 $ 1 22

57% 7$$ 20 42

5&$ 7*$ 24

5$ 7* 25 #1

57$$ & % #8

Pan 7$ 2 100

D:

MRR1RMMRH+RH?+00

*.!

) Th ith th D: * ! d th



)6& The ne agg. with the D:*.! and thecoarse agg. with the D:7.?! areavailable. 9ombine them in such a wa$

that the D: becomes M.?

S & olume of Dine agg.

*.!SR7.?!5+00S +00

M.? S *

I*" of ne agg. and 77" of coarse agg. should bemi6ed.



=ranulometr$&

. The D: is not alwa$s representative

of the gradation of an aggregatesample and various gradation curvesma$ give the same D:.

.

n the gradation curves, the verticala6is represents the " passing - thehoriContal a6is represents the sieveopening.

. A logarithmic scale is used forhoriContal a6is.



A good aggregate gradation for a particularconcrete is the one that leads to a wor/able,

dense - uniform concrete, without an$



There is no single FidealG grading curve.nstead, standards provide upper - lower

limits.



AS"M 0e8uirement for

9ASie/e 2 Paing

3/8' 100

)4 #5-100

)8 80-100

)1 50-85

)30 25-0

)50 10-30

)100 2-10

AS"M 0e8uirement for CA

Sie/e2 Paing

7 :4+ 56 &364 + 56 73*4 + 56

3' ; ; ;

2 7' ; ; ;

2' 100 ; ;

1 7' #5-100 ; ;

1' ; 100 ;

3/4' 35-%0 #0-100 100

1/2' ; ; #0-100

3/8' 10-30 20-55 40-%0

)4 0-5 0-15 0-15

) ; 0-5 0-5

I 9hanges with ma6 aggregatesiCe

Ha"%li"g , Sto$>*ili"g o



Ha"%li"g , Sto$>*ili"g oAgg3

2andling and stoc/piling of coarseaggregates ma$ easil$ lead tosegregation. To overcome thissegregation 9A are handled and

stoc/piled in di%erent siCe fractions,such as !+!mm, +!!mm, and theseaggregates are mi6ed in specied

proportions onl$ when fed into themi6er.

coarse

r

'egregation& seperation ofparticles having di%erentsiCes

A ' / ili



Aggregate 'toc/piling



'toc/ Pile 'egregation



Aggregate Proportions

S'ECIFIC GRA;IT?



Seci&ic .ra4it2 is the ratio o& the ei.ht o& a $nit 4o%$e

o& ateria% to the 8ei.ht o& the sae 4o%$e o& ater at

"# to "5C

S'ECIFIC GRA;IT?

S'ECIFIC GRA;IT? OF AGG



S'ECIFIC GRA;IT? OF AGG3

'p.=r. is used in certaincomputations for concrete mi6

design or control wor/, such as,absolute volume of aggregate inconcrete. t is not a measure of the#ualit$ of aggregate.

'p.=r.

(r$ <eight of Agg.

5<A<eight of an e#ual volume of water5AIw

<A

AIw

A

w

(ensit$ ofAgg.(ensit$ of

<ater



;olme o Aggregate@

&OISTRE CON=ITION OF



&OISTRE CON=ITION OFAGGREGATES

&OISTRE CON=ITION OF



&OISTRE CON=ITION OFAGGREGATES

o"e =r! B Oe" =r! (O=) means theaggregate contains no moisture. This re#uiresdr$ing the aggregate in an oven to a constantmass.

Satrate% Sra$e-=r! (SS=) the aggregateUsvoid are lled with moisture but the main surfacearea of the aggregate particle is dr$.A#or*tio" is dened as the moisture content in

the ''( condition.&oi#t Aggregate# have a moisture content ine6cess of the ''( condition.Free &oi#tre is the di%erence between theactual moisture content of the a re ate and



Apparent Specific ;ra/it<

O4era%% 4o%$e o& the a..re.ate e+c%$si4e o& the 4o%$e o& the ores or

Cai%%aries hich becoe &i%%e* ith ater in "' hrs o& soain.



Bul =nit >eight an1 ?oi1 in AggreagateO4era%% 4o%$e o& the a..re.ate e+c%$si4e o& the 4o%$e o& the ores

or The b$% $nit ei.ht o& a..re.ates is nee* &or

the roortionin. o& ort%an* ceent concrete

i+t$res A ri.i* container o& non 4o%$e is

&i%%e* ith a..re.ate, hich is coacte* either b2ro**in., >i..in., or sho4e%in. The b$% $nit

ei.ht o& a..re.ate (Vb is determined as&

<here W# is the weight of aggregate

and ; is the volume of the container



Bul =nit >eight an1 ?oi1 in AggreagateO4era%% 4o%$e o& the a..re.ate e+c%$si4e o& the 4o%$e o& the ores

or ?& the b$% *r2 seci&ic .ra4it2 o& the a..re.ate

(sb) is non, the ercenta.e o& 4oi*s beteen

a..re.ate artic%es can be *eterine* as <

6 +00 6 +00

<here&

;# volume of aggregateVs unit weight of aggregate

Vb bul/ unit weight of aggregate

Vw unit weight of water

9 A



+ 9oarse Agg.. Aggs are oven dried at +0!X!Y9

overnight - the weight is measuredas 5A*oen dry weight. ggs are soaked in water .or 24 hours. ggs are taken out .rom water rolled in a

large a,sor,ent cloth until all isi,le .ilmso. water are remoed then weighed&<(*saturated sur.ace dry weight

. ggs are then weighed in water &+(



" Absorption

BAA

I+00

Apparent 'pecic=ravit$

A

A9

(r$ Bul/ 'pecic=ravit$

A

B9

''( Bul/ 'p.=r.

BB9

Di A



Dine Agg.

. Aggs are oven dried to constant weight at

+0!X!Y9. :easure the dr$ weight as 5A. 'oa/ them in water for 1hrs

. 'tir the sample to bring it to ''( condition.;se the 9one Test for 'urface :oisture

(etermination 5<eight as '. Dill the aggs in ''( condition into a

p$cnometer 5to a calibrated level andweight it, 5waterRp$conometerRagg 59

. Dill the p$conometer with water onl$ 5to acalibrated level and weight it5waterRp$conometer 5B



O A..re.ate(A)

Container ith H"O

(0)

Container ith H"O

an* ith

A..re.ate

(C)

Specific ;ra/it< "et for San1

SS A..re.ate(S)



" Absorption

'AA

I+00

Apparent 'pecic=ravit$

A

BRA9

(r$ Bul/ 'pecic=ravit$

A

BR'9

''( Bul/ 'p.=r.

'BR'9



Sam*le 'rolem+

A sample of sand has the followingproperties&

<et mass M!. grams(r$ mass !?H.H gramsAbsorption +.M"

(etermine& a total moisture contentb free moisture content



Seat>or 7.$@O4era%% 4o%$e o& the a..re.ate e+c%$si4e o& the 4o%$e o& the ores

or Coarse a..re.ate is %ace* in a ri.i* b$cet an*

ro**e* ith a tain. ro* to *eterine its $nit

ei.ht The &o%%oin. *ata are obtaine*<

/o%$e o& b$cet ; 1=3c$&t8ei.ht o& et2 b$cet is 1!5 %b

8ei.ht o& b$cet &i%%e* ith *r2 ro**e* coarse

a..re.ate ; 559%b

a Ca%c$%ate the *r2-ro**e* $nit ei.ht

b ?& the b$% *r2 seci&ic .ra4it2 o& the

a..re.ate is "63, ca%c$%ate the ercent 4oi*s in the

a re ate

SON=NESS OF



SON=NESS OFAGGREGATES

'oundness is the abilit$ of agg to resistvolume changes to environmental

e%ects. – DreeCing - Thawing

– Alternate <etting - (r$ing

– Temperature 9hanges

SON=NESS OF




Aggs are said to be unsound whenvolume changes induced b$ the above,

results in deterioration of concrete. This e%ect ma$ be& – ocal scaling

– )6tensive surface crac/ing

– (isintegration over a considerable depth

SON=NESS OF



To detect unsound particles, aggs aretreated with 8a'L1 or :g'L1 solutions.

–+? hours of immersion

– (r$ at +0!Y9R!Y9 to constant weight

– After ! c$cles determine the loss in weightof the agg.


SON=NESS OF



According to T' following limitsshould not be e6ceeded.

8a'L1 :g'L

1

Dine Agg.

9oarseAgg.

+H"

"+!"

7"


ARASION RESISTANCE



ARASION RESISTANCE )speciall$ when concrete is used in roads

or Joor surfaces subOected to heav$ traZcload.

2ardness, or resistance to wear 5abrasion

is determined b$ osAngeles abrasiontest.

os Angeles Abrasion Test&



os Angeles Abrasion Test&

The agg with a specied grading is

placed inside the .A. Testing :achine oose steel balls are placed inside the

drum

The apparatus is rotated for aspecied c$cles

Dinall$ the loss in weight is

determined. b$ screening with K+sieve.

4esistant * "10: .or 100 reolutions

* "50: .or 500 reolutions

Al> li A t



Al>ali- AggregateRea$tiit! ( AAR )

[ is a reaction between the activemineral constituents of some

aggregates and the sodium andpotassium al/ali h$dro6ides andcalcium h$dro6ide in the concrete.

–Al/ali'ilica 4eaction 5A'4 –Al/ali9arbonate 4eaction 5A94

Al>ali-Sili$a Rea$tio"



a S $a ea$ o(ASR)

isual '$mptoms – 8etwor/ of crac/s

– 9losed or spalled Ooints

– 4elativedisplacements




isual '$mptoms5cont. – Dragments brea/ing out of

the surface 5popouts echanism

1$ lkali hydroide reactie

silica gel ⇒ reaction

product &alkali-silica gel(

2$ =el reaction product

moisture ⇒ epansion

Al>ali-Sili$a Rea$tio"(ASR)




nJuencing

Dactors – 4eactive forms ofsilica in theaggregate,

– 2ighal/ali 5p2pore solution

– 'uZcient moistureIf one of these conditions is

absent ― ASR cannot occ!"

Al>ali-Sili$a Rea$tio"(ASR)




Test :ethods – :ortarBar :ethod 5A'T: 7

–

9hemical :ethod 5A'T: 9 ?H – Petrographic )6amination 5A'T: 9 H!

– 4apid :ortarBar Test 5A'T: 9 +M0

– 9oncrete Prism Test 5A'T: 9 +H*

Al>ali Sili$a Rea$tio"(ASR)




9ontrolling A'4 – 8onreactive aggregates

–

'upplementar$ cementing materials orblended cements

– imit al/alis in cement

– ithiumbased admi6tures

– imestone sweetening 5~*0"replacement of reactive aggregate withcrushed limestone

Al>ali Sili$a Rea$tio"(ASR)

E<e$t o S**leme"tar!



** !Ceme"ti"g &aterial# o"

ASR

&A. AGG SIE



&A. AGG SIE

tUs the smallest sieve siCe through

which the entire amount of the aggparticles can pass.

The larger the siCe of agg, the smallerthe surface area to be wetted per unitweight. Thus, e6tending the grading ofagg to a larger ma6 siCe lowers thewater re#uirement of the mi6. 'o, forthe same wor/abilit$ - cement contenthigher strength will be obtained.

Lptimum ma6 agg siCe for structural



Lptimum ma6 agg siCe for structuralconcrete is !mm.

'tudies have shown that concreteUsmade with ma6 agg siCe greater than

10mm have lower strength. Because ofthe smaller surface area for the bondbetween agg to paste. olumechanges in the paste causes larger

stresses at the interface.

Sta"%ar% Limitatio"# or &aDAgg Si0e



Agg Si0e

The concrete mi6 must be so that, it

can be placed inside the molds andbetween the reinforcing bars easil$without an$ segregation. 'o, ma6 agg

siCe 5(ma6 should not e6ceed&

+ +3! of the narrowest dimension of themold.

d

d+

d*

dmin 5d+,d,d*

(ma6 @d

!

+3* of the depth of the slab



p

h

slab(ma6 @

h

*

* \ of the clear spacing betweenreinforcement

'

'&face of thedistance

(ma6 @*

1'

1 (ma6 @ 10mm

)6ample&



)6ample&

slab

!cm

Mcm

0c

m

10c

m

Hc

m

beam

]+0mm

(ma6Q

+ (ma6 @ +3! min50,101cm

(ma6 @ +3*5H*cm(ma6 @ *cm

Documents

Lecture 1- Aggregates