Project on Concrete Mix Design for various grades of Concrete
Calculate the concrete mix design for M35 grade concrete with fly ash and M50 grade concrete without fly ash
Calcultion:
Target mean strength
F’ck= Fck +1.65s
F’ck=35 N/mm^2
S=5 N/mm^2
F’ck=35+(1.65)*5
=43.25 N/mm^2
2) selection of water cement ratio
Given,
M35
Table IS 456:2000
w/c =0.40
M35=w/c=0.45
Water cement ratio =0.40
Minimum cement ratio =360 kg/m^3
Table 456:2000
3) selection of water content
IS10262:2009 nominal size of aggregate=20mm
Minimum water content = 186
20% reduced
=186*80/100 =148.8
Water content 149 liters
4) calculation of cement content
( Cement + fly ash)
w/c =0.40
Water content w=149kg
C=149/0.40
=372.5 =370 kg/m^3
Minimum cemnt content =360 kg/m^3
360<370 kg/m^3
Increase 10%
370*0.10 +370=407kg/m^3
W=149kg
Water content ratio =149/407 =0.365
Fly ash at 30%
= 407*30/100= 122 kg/m^3
Cement =407-122 = 285 kg/m
Saving of cement while using fly ash =370-285 =85 kg/m^3
Fly ash =122 kg/^3
5) volume of coarse aggregate and fine aggregate
IS 383
Size of aggregate =20mm
Fine aggregate zone 1
Volume of coarse aggregate =0.60
Warer cement ratio = 0.40
Volume of aggregate =1-0.62 =0.38
6) Mix Calculation
- volume of concrete =1m^3
- volume of cement =285/3.15*1/1000 = 0.090m^3
- volume of Fly Ash = (122/2.2) *1/1000 = 0.055m^3
- volume of water = (149/1) *1/1000 = 0.149m^3
- volume of Admixture = (7.6/1.145) *1/1000 = 0.006m^3
- volume of coarse aggregate and fine aggregate =a(-b+c+d+e)
=1(-0.090+0.055+0.149+0.006) =0.7m^3
- mass of coarse aggregate = 0.7*0.62*2.74*1000 =1189.16 kg/m^3
- mass of fine aggregate =0.7*0.38*2.74*1000 = 728 kg/m^3
Result and conclusion
Trial mix
Cement = 285 kg/m^3
Fly Ash = 122 kg/m^3
Water = 149 kg
Coarse aggregate = 1189 kg/m^3
Fine aggregate = 728 kg/m^3
Chemical Admixture = 7.6 kg/m^3
Water cement ratio = 0.366
Trial mix ratio 285:728:1189 = 1:2.55:4.17 (C: FA:CA)
- This trial mix ratio should match the workability, durability minimum strength of M35 grade concrete.
- If it does not satisfy the above criteria two or more trials for increase of 10% should be done.
* To calculate M50 Grade without Fly Ash
Calcultion:
Target mean strength
F’ck= Fck +1.65s
F’ck=50 N/mm^2
S=5 N/mm^2
F’ck=50+(1.65)*5
=58.25 N/mm^2
2) selection of water cement ratio
Given,
M50
Table IS 456:2000
w/c =0.40
M35=w/c=0.45
Water cement ratio =0.40
Minimum cement ratio =360 kg/m^3
Table 456:2000
3) selection of water content
IS10262:2009 nominal size of aggregate=20mm
Minimum water content = 186
20% reduced
=186*80/100 =148.8
Water content 149 liters
4) calculation of cement content
( Cement + fly ash)
w/c =0.40
Water content w=149kg
C=149/0.40
=372.5 =373 kg/m^3
Minimum cemnt content =360 kg/m^3
360<373 kg/m^3
5) volume of coarse aggregate and fine aggregate
IS 383
Size of aggregate =20mm
Fine aggregate zone 1
Volume of coarse aggregate =0.60
Warer cement ratio = 0.40
Volume of aggregate =1-0.62 =0.38
6) Mix Calculation
- volume of concrete =1m^3
- volume of cement =373/3.15*1/1000 = 0.118m^3
- volume of water = (149/1) *1/1000 = 0.149m^3
- volume of Admixture = (7.6/1.145) *1/1000 = 0.006m^3
- volume of coarse aggregate and fine aggregate =a(-b+c+d+e)
=1(-0.118+0.149+0.006) =0.727m^3
- mass of coarse aggregate = 0.727*0.62*2.74*1000 =1235.02 kg/m^3
- mass of fine aggregate =0.727*0.38*2.74*1000 = 756.9 kg/m^3
Result and conclusion
Trial mix
Cement = 373 kg/m^3
Water = 149 kg
Coarse aggregate = 1235.9 kg/m^3
Fine aggregate = 756 kg/m^3
Chemical Admixture = 7.6 kg/m^3
Water cement ratio = 0.38
Trial mix ratio 373:756:1235.02 = 1: 2.02: 3.31 (C: FA:CA)
- This trial mix ratio should match the workability, durability minimum strength of M50 grade concrete.
- If it does not satisfy the above criteria two or more trials for increase of 10% should be done.