MainCONCRETE MIX DESIGN (as per IS10262-1982)Data for Mix designM15Maximum size of aggregate (MSA)=20mm(only 10mm, 20mm and 40mm allowed)Nature of Coarse aggregate=1(Enter 1 for crushed(angular), 2 for rounded)Fine aggregate conforms to3(Enter 1 for Zone I, 2 for Zone II, 3 for Zone III, 4 for Zone IV)Specific Gravity ofCement3.13Fine aggregate2.63Coarse aggregate2.82Type of exposure5(Enter 1 for Mild, 2 for Moderate, 3 for Severe, 4 for Very severe, 5 for Extreme)Degree of Quality controlWorkabilityCompacting factor=0.8Target mean strength of concreteTarget mean strength of concrete for M15 grade concrete assuming accepted proportion of low results as 1 in 20fck=fck+t*s=15 + 1.65*3.5=20.775N/mm2Selection of water cement ratioFrom Fig.1 of IS 10262-1982 for 28 days target mean strength of 20.775N/mm2after interpolation W/C ratio=0.6544(rounded off to4decimals)Selection of Water Content and Fine to Total aggregate ratioFrom table 4 of IS 10262-1982 for max. size of aggregate as 20mm for one cum of M15 absolute vol. of concreteWater content (assuming ssd agg.)=186These values are as per standard conditionskgSand to Total aggregate ratio=35%After correction is appliedWater content (assuming ssd agg.)=186Kg(W)Sand to Total agg. ratio (p x 100)=34.588%Calculation of Cement contentCement Content (C )=186 / 0.6544=284.2298288509KgMin. Cement content required as per table 5 of IS 456-2000 assuming RCC is 360KgCalculation of Aggregate contentAs per the formula given vide 3.5.1 of IS 10262-1982with usual notationsV = [ W + C/Sc + 1/p. fa/Sfa ] x 1/1000(for calculating fine aggregate content)Absolute Volume of fresh concrete=0.98Sand content (fa)=639.668499503KgV = [ W + C/Sc + 1/(p-1). Ca/Sca ] x 1/1000(for calculating Coarse aggregate content)Coarse aggregate content (Ca)=1297.1204370354KgThe mix proportion as worked out as per IS 10262-1982 isWt/cum1kg of cem50kg of cemWater1860.654432.72Cement360150Fine aggregate639.6684995031.776856943188.8428471532Coarse aggregate1297.12043703543.6031123251180.1556162549

CalculationsApproximate air contentNominal MSAEntrapped airWater contentFA/TA10320840s in fck+t * s expression=3.5202186354011653028 day strength verses water cement ratio510.3430.35400.3736.50.4310.45300.46260.5250.51522.50.55200.59190.616.50.65fck bar=20.775upper lmt2.50.55300.4lower lmt200.65200.59intrapolation for w/c ratio0.6544285714zone of sandComp.factW/C ratioroundedTot Corrwater content186correction00000FA/TA ratio35-1.501.0880-0.412Min cement content as per exposure conditions (assuming RCC)360