Project on Concrete Mix Design for various grades of Concrete
M35 grade concrete design mix with fly ash
Target mean strength
f'ck= fck+1.65S
f'ck= 35+(1.65x5)
F'ck= 43.25 N/mm2
w/c ratio
Table 5 of IS 456 2000 bsed on severe exposure 0.45
Based on 0.37<0.45
Water content
table of IS 10262 2009 water content for 20mm aggregate is 186 lit for 25mm to 50mm slump
for every 25mm slump 3% of water is added
=186+ ((6/100)x186)
=197 lit
As super plasticizer added 30% of water reduced and for trials take 29%
=197x 0.71
= 140 lit
Calculation of cement content
0.37=140/cement
cement= 140/0.37
cement= 378kg
as per is 456 2000 based on severe exposure condition min cement content 320kg/m3
378kg/m3 < 350kg/m3
proportion of fly ash content in mix
10% of cementitious material content= 378x 1.10= 416 kg
water content= 140/416= 0.336
30% of fly ash content in the cement= 416x 30%= 125kg/m3
cement content= 416-125= 291kg/m3
saving of cement= 378- 291= 87 kg/m3
proportion of coarse aggregate and fine aggregate
for 2omm aggregate with water cement ratio 0.5 the max vol of coarse aggregate to fine aggregate is 0.6
for 0.37= 0.63
for pumpable concrete reduce 10% of coarse aggregate
= 0.37x 90%= 0.558
= 1-0.558= 0.442
Mix proportion
a) vol of concrete= 1m3
b) Vol of cement= (mass of cement/ specific gravity of cement) x (1/1000)
= (291/3.15) x (1/1000)
= 0.09m3
c) vol of fly ash= (mass of fly ash/specific gravity of fly ash) x (1/1000)
= (125/2.2)x(1/1000)
= 0.057m3
d) vol of water content= ( Mass of water/ specific gravity of water) x(1/1000)
= ( 140/1) x (1/1000)
= 0.14m3
e) Vol of chemical admixture= (mass of chemical admixture/specific gravity of chemical admixture)x(1/1000)
2% of cementitious material= 416x2%
= (8.32/1.145) x (1/1000)
= 0.007m3
f) Vol of aggregate= a- (b+c+d+e)
= 1- (0.09+0.057+0.14+.007)
=0.706
g) Mass of coarse aggregate= f x vol of aggregate x specific gravity of coarse aggregatex 1000
= 0.706 x 0.558x 2.74x 1000
= 1079 kg/m3
h) Mass of Fine aggregate= f x vol of aggregate x specific gravity of coarse aggregatex 1000
= 0.706 x 0.442x 2.74x 1000
= 855 kg/m3
Mix proportion
cement= 291kg/m3
fly ash= 127kg/m3
coarse aggregate= 1079kg/m3
fine aggregate= 855kg/m3
chemical admixture= 8.32kg/m3
water content= 140
w/c ratio= 0.37
proportion= 1:2.94:3.70
M50 grade without fly ash
Target mean strength
f'ck= fck+1.65S
f'ck= 50+(1.65x5)
F'ck= 58.25
w/c ratio
Table 5 of IS 456 2000 bsed on severe exposure 0.45
Based on experience w/c ratio is 0.30<0.45
Water content
table of IS 10262 2009 water content for 20mm aggregate is 186 lit for 25mm to 50mm slump
for every 25mm slump 3% of water is added
=186+ ((6/100)x186)
=197 lit
As super plasticizer added 30% of water reduced and for trials take 29%
=197x 0.71
= 140 lit
Vol of cement
0.30= 140/c
cement = 140/0.30
=467 kg/m3
As per IS 456 2000 table 5 min cement content for severe exposure is 320kg/m3
350kg/m3 < 467 kg/m3
Vol of aggregate
As per IS 10262 2009 table for zone 1 fine aggregate for w/c ratio of 0.5 is 0.6
0.001 is added for every 0.05 w/c decreases
then, for 0.3 w/c = 0.6+0.04
= 0.64
for pumpable for concrete 10% aggregate is reduced
= 0.64 x 0.90
=0.576
vol of fine aggregate
= 1 - 0.0576
=0.424
Mix calculation
a) Vol of concrete= 1m3
b) Vol of cement= (mass of cement/ specific gravity of cement) x (1/1000)
= (467/3.15) x (1/1000)
= 0.148m3
c) vol of water content= ( Mass of water/ specific gravity of water) x(1/1000)
= ( 140/1) x (1/1000)
= 0.14m3
d) Vol of chemical admixture= (mass of chemical admixture/specific gravity of chemical admixture)x(1/1000)
2% of cementitious material= 467x2%
= (9.34/1.145) x (1/1000)
= 0.008m3
e) Vol of coarse aggregate and fine aggregate
= a - ( b+c+d)
= 1 - ( 0.148 + 0.14 + 0.008)
= 0.704
f) Mass of coarse aggregate
= e x vol of aggregate x specific gravity of coarse aggregatex 1000
= 0.704 x 0.576 x 2.74 x 1000
= 1111 kg/m3
Mass of Fine aggregate= e x vol of aggregate x specific gravity of coarse aggregatex 1000
= 0.704 x 0.424x 2.74x 1000
= 817 kg/m3
Mix proportion
cement= 467kg/m3
coarse aggregate= 1111kg/m3
fine aggregate= 817kg/m3
chemical admixture= 9.34kg/m3
water content= 140
w/c ratio= 0.3
proportion= 1:1.75:2.38