Project on Concrete Mix Design for various grades of Concrete
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Calculate the Concrete Mix Design for M35 grade concrete with fly ash & M50 grade concrete without Fly ash |
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M-35 concrete with fly ash: Target strength for M35 is calculated as =fck+1.65s=35+1.65x5=43.25N/mm2. 2.Water cement ratio is calculated from the graph of is 10262 , table 5 of IS 456 and IS 4031, the lowest of which comes around 0.39 Taking minimum cement content as 340kg/cum. 3.Water content is determined from table 2 of is 10262 based on nominal size of aggregate. Water content is corrected for use of admixture. Fromtable 2 , for 20mm nominal size of aggregate , maximum water content comes to 186 litres. This slump is for 25 to 50 mm slump. For 100 mm slump , this slump is corrected , 186+6*100/186=197 litres. Reducing water content by 29 percent for superplacticiser, water content comes to 197*.71=140 litres. Water cement ratio=0.39 Cement+flyash = 140/0.39=358.97 kg which is approximated to 360 kg/cum. Cementitious content is increased by 10% on account of use of flyash, So cementitious content =360*1.1=396 kg/cum Assuming 30% flyash content, Flyash=0.3*396=118.8 kg approximated to 119kg/cum. Cement content =396-119=277kg/cum Saving of cement while using flyash=360-277=83kg/cum 4.Proportion of coarse and fine aggregate is calculated based on table 3 of IS 10262. Volume of coarse aggregate corresponding to 20mm nominal size of aggregate and fine aggregate zone-I, for water cement ratio of 0.5=0.6 Corrected proportion of coarse aggregate come to = 0.6 +(0.5-0.39)*0.01/0.05=0.622 Reducing the value by 10 percent for pumpable concrete Volume of coarse aggregate= 0.622*0.9=0.56 Volume of fine aggregate=1-0.56=0.44 Volume of concrete=1cum Volume of cement=277/(3.15*1000)=0.087cum Volume of flyash=119/(2200)=0.054cum Volume of admixture @ 2% of the weight of cementitious content=7.2/1145=0.006cum Volume of all aggregate=1-(0.087+0.054+0.006+0.140)=0.713 cum Mass of coarse aggregate=0.713*0.56*2.74*1000=1094 kg Mass of fine aggregate=0.713*0.44*2.74*1000=859.59 kg approximated to 860 kg. Summary of mix proportion M-35 with flyash Cement-277kg/cum Flyash-119kg/cum Water-140kg/cum Coarse aggregate-1094kg/cum Fine aggregate-860kg/cum Chemical admixture-7.2kg/cum M-50 concrete without fly ash: Target strength for M50 is calculated as =fck+1.65s=50+1.65x5=58.25N/mm2. 2.Water cement ratio is calculated from the graph of is 10262 , table 5 of IS 456 and IS 4031, the lowest of which comes around 0.36 Taking minimum cement content as 360kg/cum. 3.Water content is determined from table 2 of is 10262 based on nominal size of aggregate. Water content is corrected for use of admixture. Fromtable 2 , for 20mm nominal size of aggregate , maximum water content comes to 186 litres. This slump is for 25 to 50 mm slump. For 100 mm slump , this slump is corrected , 186+6*100/186=197 litres. Reducing water content by 29 percent for superplacticiser, water content comes to 197*.71=140 litres. Water cement ratio=0.39 Cement = 140/0.36=388.88 kg which is approximated to 390 kg/cum. 4.Proportion of coarse and fine aggregate is calculated based on table 3 of IS 10262. Volume of coarse aggregate corresponding to 20mm nominal size of aggregate and fine aggregate zone-I, for water cement ratio of 0.5=0.6 Corrected proportion of coarse aggregate come to = 0.6 +(0.5-0.36)*0.01/0.05=0.628 Reducing the value by 10 percent for pumpable concrete Volume of coarse aggregate= 0.628*0.9=0.56 Volume of fine aggregate=1-0.56=0.44 Volume of concrete=1cum Volume of cement=390/(3.15*1000)=0.124cum Volume of admixture @ 2% of the weight of cementitious content=7.8/1145=0.006cum Volume of all aggregate=1-(0.123+0.006+0.140)=0.731 cum Mass of coarse aggregate=0.731*0.56*2.74*1000=1121 kg Mass of fine aggregate=0.731*0.44*2.74*1000=881.29 kg approximated to 881 kg. Summary of mix proportion of M-50 without flyash Cement-390kg/cum Water-140kg/cum Coarse aggregate-1121kg/cum Fine aggregate-881kg/cum Chemical admixture-7.8kg/cum |