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MIX DESIGN AND PROPORTIONING GUIDELINE FOR NORMAL CONCRETE

(ABSOLUTE VOLUME METHOD)

Specificatio! (De!i")#

1. Exposure condition: Concrete protected from freezing to thawing.2. Design compressive strength: 3000 psi at 28 das.

3. !ir inc"uded: #o.

$. %"ump: 3&$ in.'. !ggregate maximum nomina" size: 0.' in.

(. #orma" cement )%pecific gravit: 3.1'*

+. %pecific gravit for coarse aggregate: 2.+8

8. Coarse aggregate a,sorption: 1.1-.-. /vendr rodded ,u" densit )nit weight* for coarse aggregate: -8.( ",ft3

10. !ggregate moisture at the time of testing: 2.

11. %pecific gravit for fine aggregate: 2.$1

12. ine aggregate a,sorption: 113. ine aggregate moisture at the time of testing: 1.+1.

1$. ine aggregate fineness modu"us: 2.80

Step!#

1. Chec 4a,"e 12.1 for exposure condition and compare the minimum compressive

strength with the design strength. Design strength shou"d ,e e5ua" or higher to the

m6nimum specified in the ta,"e.

2. %ince there is no statistica" data7 go to ta,"e 12.10 and add the factor that corresponds to

the design strength range.

f '  (c )=3000+1200=4200 psi

3. Ca"cu"ate the re5uired watercement ratio to achieve the desired compressive strength7 ,means of interpo"ation if necessar )4a,"e 12.3*.

w

c

 = (5000−4200 )(0.57−0.48)

(5000−4000)

  +0.48=0.552

$. #ow we go to 4a,"e 12.'. rom the co"umns we se"ect the one that corresponds to the

aggregate maximum nomina" size )$%&  in* inside the section of #on&!ir EntrainedConcrete. rom there7 we can see that the approximate amount of entrapped air is $%$'&.

4hen we chec the "ine that corresponds to the design s"ump )* i* and we can see that

the water content of the concrete shou"d ,e +,& -.! pe/ 01.

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'. 4he cement content is therefore:

Cement =Water

w /c  =

  365

0.552=664 lbs per yd

3

(. 4he coarse aggregate content is ca"cu"ated ,ased on 4a,"e 12.$. %ince our aggregatemaximum nomina" size is $%& i and the fine aggregate fineness modu"us is '%2$ 7 the ,u" vo"ume of dr&rodded coarse aggregate per unit vo"umen of concrete is $%&& .

%ince the aggregate ovendr rodded ,u" densit is 32%,$ 7 the mass of coarse aggregate

to use in the design is:

Coarse aggregate mass=98.6 lb / ft 3

×0.55×27 ft 3/ yd

3=1464.21 lb per yd3

+. 4he fine aggregate content is determined as the difference ,etween the tota" vo"ume of 

the concrete minus the nown components of the mix )cement7 water7 air and coarse

aggregate*7 therefore7 first the vo"ume of these components must ,e ca"cu"ated:

Water=  365 lb

1.0×62.42796 lb / ft 3

×27 ft 3/ yd

3=0.22 yd

3

Cement =  664 lb

3.15×62.42796 lb /ft 3

×27 ft 3/ yd

3 =0.13 yd

3

 Air=2.5

100=0.025 yd

3

Coarseaggregate=  1464 lb

2.78×62.42796 lb / ft 3 ×27 ft 3 / yd3

 =0.31 yd3

 Fine aggregate=1.0−0.22−0.13−0.31−0.025=0.32 yd3

4herefore the mass of the fine aggregate is:

2.64×0.32×62.42796 lb / ft 3

×27 ft 3/ yd

3=1424 lb per yd3

8. %ince the aggregates wi"" ,e used in the wet condition7 their proportions shou"d ,e

adusted as fo""ows:

Coarseaggregate (1.20 MC )=1.012×1464=1482 lb

 Fineaggregate (1.71 MC )=1.017×1424=1448lb

-. 4he water content shou"d a"so ,e adusted:

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¿−[1424 lb x (1.7−1.7 )]=365 lb

Water=365 lb−¿

10. 4he mass of ever component to mix 1 d3 of concrete is therefore the fo""owing:

9ater )to ,e added*: 3(' ",Cement (($ ",Coarse aggregate )2 C*: 1$82 ",

ine aggregate )0.' C*: 1$$8 ",

Tota- -.

11. 4he "ast step is to ca"cu"ate weights for a tria" ,atch of a tota" vo"ume of 1 ft3.

12. 4he "ast step is to ca"cu"ate weights for a tria" ,atch of a tota" vo"ume of 0.1 m3:

9ater )to ,e added*: 3(' ", x 12+ ; 13.'2 ",

Cement (($ ", x 12+ ; 2$.(0 ",

Coarse aggregate )2 C*: 1$82 ", x 12+ ; '$.-0 ",ine aggregate )0.' C*: 1$$8 ", x 12+ ; '3.(3 ",

Tota- -. 4 12+ 5 -.