PPT ON MASS CONCRETE MIX PROPORTIONING

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1.MASS CONCRETE MIX PROPORTIONING

2.Generally,lower grade of concrete
                   M10,M15
Bigger size of aggregate:75mm,150mm             maximum size of aggregate(MSA).
Water-reducing admixtures(Plasticizers)
     & air-entraining admixture to improve
     cohesiveness of concrete mix.

3.Grading Requirement for 150mm MSA

4.Grading Requirement for 75 mm MSA

5.CRUSHED STONE FINE AGGREGATE

6.Table 1 W/C RATIO VS 28-DAY COMPRESSIVE STRENGTH OF AIR-ENTRAINED CONCRETE(ACI 211.1)

7.MIXING WATER REQUIREMENT(kg/m3 of concrete)in NON-AIR ENTRAINED CONCRETE

8.Max. w/c ratio for Mass Concrete(ACI 211.1)

9.Minimum cement content, maximum W/C and minimum grade of concrete for different exposures

10.ADJUSTMENTS

11.VOL. OF COARSE AGGREGATE

12.MORTAR & AIR CONTENT

13.SUGGESTED STANDARD DEVIATION VALUES

14.Worked out Example
DESIGN STIPULATIONS
Grade of Concrete :M15 (Water front structure)
   Cement             :PSC(with 55% g.g.b.s)
Workability of Concrete: 40mm slump
Max. size of crushed rock aggregate:150mm
Exposure Condition : Moderate
Quality control expected to be exercized
                  at site  : Good

15.TEST DATA ON MATERIALS

16.FINE AGGREGATE

17.Concrete Mix Proportions

18. The cement content=125/0.50=250Kg/m3.
This cement content is to be increased by
   10%,because it is PSC.
  .: Cement content=250x1.1=275kg/m3.
     The proportion of C.A(from Table5)
       =77% of total aggregate by absolute
            volume.(For the F.M of FA of 2.6).
 .: % of fine aggregate=23%(having the
     same sp.gr as that of C.A).

19.CALCULATION OF QUANTITIES OF MATERIALS(Absolute

20.Absolute Vol.of Mortar

21.QUANTITIES OF ALL INGREDIENTS