Project on Concrete Mix Design for various grades of Concrete
Answer - Basic Details used in design of concrete
Designed Grade =M35
Cement Used =OPC43 Grade
Aggregate size not more than =20mm
Minimum cement content = 320Kg/CBM
Water cement ratio = 0.45
workability =100mm slump
Method of placing concrete = Pumping
Procedure for Mix Design:
1)Target mean strength f'ck=fck+1.65s
= 35+1.65*5 = 43.25N/mm2
fck= Charecterstic strength
s= Standard Deviation
2) Consider W/c = 0.4
3) For 100mm Slump = 186+(6/100)*186 = 197 Liters
As super plastisizer is used 30% water can be reduced hence final Water quantity = 138 Liters = 140Lts Approx
4) W/c = 0.4
=140/C=0.4
i.e c = 350Kgs
As we are using fly ash we can reduce cement upto 30%
I.e 30%*350 = 105Kgs
Totla Cementesious Material
Cement = 245Kgs
Fly Ash = 105 Kgs
5) Calculation of Course & Fine aggregate
From table 3 IS1026
Course aggregate = 0.6 for W/c 0.5
For W/c 0.4 = We can consider 0.64 for corse aggregate
For Pumpable concrete 10% of aggregate can be reduced
Volume of Corse aggregate = 0.64*0.9= 0.576
Volume of fine aggregate = 1-0.576 = 0.424
Final Mix Calculation:
a) Volume Of Concrete = 1M^3
b) Volume of cement = (Mass of cement / Specific Gravity of Cement)*1/1000
= (270/3.15)*1/1000 = 0.085m^3
c) Volume of Fly Ash = (Mass of fly ash / Specific Gravity of Fly Ash)*1/1000
= (105/2.2)*1/1000 = 0.047m^3
d) Volume of water = (Mass of water / Specific Gravity of Water)*1/1000
= (140/1)*1/1000 = 0.14M^3
e) Volume of Admixture = (mass of admixture / SG of admixture)*1/1000
= (7.6/1.145)*1/1000
= 0.006M^3
f) Volume of Aggregate = a-(b-c-d-e)
= 1-0.085-0.047-0.14-0.006
= 0.722
g) Mass of Corse aggregate = f*volume of corse aggregate*SG of corse aggregate
= 0.728*0.576*2.74*1000
= 1148 Kgs
h) Mass of fine aggregate = f*volume of fine aggregate*SG offine aggregate
= 0.728*0.424*2.74*1000
= 845 Kgs
Finally the mix ratio for M35 = 1:2.15:2.94
M50 Grade Mix Design:
Procedure for Mix Design:
1)Target mean strength f'ck=fck+1.65s
= 50+1.65*5 = 58.25N/mm^2
fck= Charecterstic strength
s= Standard Deviation
2) Consider W/c = 0.4
3) For 100mm Slump = 186+(6/100)*186 = 197 Liters
As super plastisizer is used 30% water can be reduced hence final Water quantity = 138 Liters = 140Lts Approx
4) W/c = 0.4
=140/C=0.4
i.e c = 350Kgs
As we are using fly ash we can reduce cement upto 30%
I.e 30%*350 = 105Kgs
Totla Cementesious Material
Cement = 245Kgs
Fly Ash = 105 Kgs
5) Calculation of Course & Fine aggregate
From table 3 IS1026
Course aggregate = 0.6 for W/c 0.5
For W/c 0.4 = We can consider 0.64 for corse aggregate
For Pumpable concrete 10% of aggregate can be reduced
Volume of Corse aggregate = 0.64*0.9= 0.576
Volume of fine aggregate = 1-0.576 = 0.424
Final Mix Calculation:
a) Volume Of Concrete = 1M^3
b) Volume of cement = (Mass of cement / Specific Gravity of Cement)*1/1000
= (350/3.15)*1/1000 = 0.111m^3
c) Volume of water = (Mass of water / Specific Gravity of Water)*1/1000
= (140/1)*1/1000 = 0.14M^3
d) Volume of Admixture = (mass of admixture / SG of admixture)*1/1000
= (7.6/1.145)*1/1000
= 0.006M^3
e) Volume of Aggregate = a-(b+c+d)
= 1-(0.111+0.14+0.006)
= 0.743M^3
f) Mass of Corse aggregate = f*volume of corse aggregate*SG of corse aggregate
= 0.722*0.576*2.74*1000
= 1139 Kgs
g) Mass of fine aggregate = f*volume of fine aggregate*SG offine aggregate
= 0.722*0.424*2.74*1000
= 845 Kgs
Finally the mix ratio for M50 = 1:2.46:3.35