Project on Concrete Mix Design for various grades of Concrete
- concrete mix design for M50 grade concrete without flyash
a)target mean strength = 50+1.65x5 (table 8 of IS 456:2000)=58.25 N/mm2
b)W/C ratio =0.5 ( table 5 IS 456:2000) for Reinforced concret of moderate exposure
W/C ratio according to fig.1 of IS 10262:2009=0.34
c)water content for 20mm size of nominal aggregate = 186kg (Table 2, IS 10262:2009)
d)calculation of cement content , C=W/(W/C)=186/0.5=372 kg
e) The volume of CA corresponding to 20mm size of aggregate (zone 1) of W/C ratio 0.5 =0.6
w/c ratio is 0.34 , hence we have to increase the volume of CA as to reduce the volume of FA.
The w/c ratio is lower by 0.16, hence the vol of CA is increased by 0.031.( at the rate of +/- 0.01 for every +/- 0.05 change in w/c ratio)
volume of CA=0.631 =0.63
for pumpable concrete this value is reduced by 10%=0.63*0.9=0.567=0.57
volume of FA=1-0.57=0.43
f)mix calculation
volume of concrete =1m3
volume of cement= (mass of cement/sp. gravity of cement)*(1/1000)=(372/1.35)*(1/1000)=0.2778 m3
volume of water= (mass of water /sp.gravity of water)*(1/1000)=(186/1)*(1/1000)=0.186 m3
volume of admixture=mass of admixture /sp gravity of admixture )*(1/1000)=(2%*372/1.145)*(1/1000)=0.0065 m3
volume of total aggregate=1-(0.2778+0.186+0.0065)=0.5297 m3
mass of CA =0.5297*0.63*2.74*1000 =914.36kg/m3
mass of FA=0.5297*0.43*2.74*1000 = 624.092 kg/m3
trial mix ratio = 1:1.68:2.46
- concrete mix design for M35 grade concrete with flyash
a)target mean strength = 35+1.65x5 (table 8 of IS 456:2000)=43.25 N/mm2
b)W/C ratio =0.5 ( table 5 IS 456:2000) for Reinforced concret of moderate exposure
W/C ratio according to fig.1 of IS 10262:2009=0.35
c)water content for 20mm size of nominal aggregate = 186kg (Table 2, IS 10262:2009)
d)calculation of cement content , C=W/(W/C)=186/0.5=372 kg
e) calculation of fly ash content
increase in 10% of cementitious material = 372x1.10=409.2 kg
water content =186kg
w/c ratio = 186/409.2=0.45
fly ash content (30% of cementatious material )=409.2x30%=122.72kg
cement content =249.24 kg
f) The volume of CA corresponding to 20mm size of aggregate (zone 1) of W/C ratio 0.5 =0.6
w/c ratio is 0.35 , hence we have to increase the volume of CA as to reduce the volume of FA.
The w/c ratio is lower by 0.15, hence the vol of CA is increased by 0.03.( at the rate of +/- 0.01 for every +/- 0.05 change in w/c ratio)
volume of CA=0.63
for pumpable concrete this value is reduced by 10%=0.63*0.9=0.567=0.57
volume of FA=1-0.57=0.43
g)mix calculation
volume of concrete =1m3
volume of cement= (mass of cement/sp. gravity of cement)*(1/1000)=(249.2/1.35)*(1/1000)=0.185 m3
volume of water= (mass of water /sp.gravity of water)*(1/1000)=(186/1)*(1/1000)=0.186 m3
volum eof fly ash = (mass of fly ash /sp. gravity of fly ash)*(1/1000)=(122.72/2.2)*(1/1000)=0.056
volume of admixture=mass of admixture /sp gravity of admixture )*(1/1000)=(2%*249.2/1.145)*(1/1000)=0.00435 m3
volume of total aggregate=1-(0.185+0.186+0.056+0.00435)=0.56865 m3
mass of CA =0.56865*0.63*2.74*1000 =981.603 kg/m3
mass of FA=0.56865*0.43*2.74*1000 = 669.98 kg/m3
trial mix ratio = 1:2.68:3.94