Project on Concrete Mix Design for various grades of Concrete
Aim : To calculate the concrete mix design for M50 grade concrete with out fly ash
Introduction : to know C/ W ratio and. Cement :FA : CA. Ratio as per Is -code
Procedure in detail :
Grade designation: M50
Type of cement: OPC 43 grade conforming to IS 8112
Maximum nominal size of aggregate: 20mm
Exposure type: Severe
Minimum cement content: 320 kg/m^3
Workability: 75mm slump
Method of concrete placing: pumping
Type of aggregate: Crushed angular
Maximum cement content: 450 kg/m^3
Chemical admixture : Super plasticizer
Specific gravity of cement: 3.15
Specific gravity of fine aggregate: 2.61
Specific gravity of coarse aggregate: 2.73
Coarse and fine aggregate: Grade 1
Target strength:
f'ck = fck + 1.65s
s = 5 (From table 1 of IS 10262 2009)
f'ck = 50 + (1.65 x 5) = 58.25 N/mm^2
Selection of water cement ratio:
From table 5 IS 456:2000, For severe exposure condition maximum w/c = 0.45
From IS 10262 2019, w/c for target strength 58.25 N/mm^2 = 0.4
Selection of water content:
Maximum water content = 186lit
For 75mm slump, water content = 186 + ((3/100)x186) = 191
Super plasticizer reduces 29% of water content.
Hence new water content = (71/100)x191 = 135.61
Calculating cement content:
Water/cement = 0.4
cement = 135.61/0.4 = 339.025 > 360 kg/m^3
so ,
Therefore cement content = 360 kg/m^3
Proportioning of volume of coarse and fine aggregate:
volume of coarse aggregate for w/c 0.38 = 0.624
Since the concrete is pumpable the volume of coarse aggregate is reduced by 10% = 0.624 x 0.9 = 0.56
volume of fine aggregate = 1-0.56 = 0.44
- Volume of concrete = 1m^3
- Volume of cement = (Mass of cement/specific gravity)x(1/1000)
(360/3.15)x(1/1000) = 0.114 m^3
- Volume of water = (Mass of water/specific gravity)x(1/1000)
= (135.61/1)x(1/1000) = 0.135 m^3
- Super plasticizer is upto 2% of mass of total cementitious content
= (6.78/1.15)x(1/1000) = 0.006 m^3
- Volume of aggregate = a - (b+c+d) = 1- (0.114+0.135+0.006) = 0.745m^3
- Mass of coarse aggregate = e x volume of coarse aggregate x specific gravity of coarse aggregate
= 0.745x0.56x2.73x1000 = 1139 kg
- Mass of fine aggregate = 0.745x 0.44 x 2.61*1000
= 855 kg
Mix Proportioning:
Cement = 360 kg/m^3
Fine aggregate = 855 kg/m^3
Coarse aggregate = 1139 kg/m^3
W/C = 0.4
Admixture = 7 kg/m^3
Aim : To calculate the concrete mix design for 35 grade concrete with fly ash
Introduction : to know C/ W ratio and. Cement :FA : CA. Ratio as per Is -code
Procedure in detail :
Grade designation: M35
Type of cement: OPC 43 grade conforming to IS 8112
Maximum nominal size of aggregate: 20mm
Exposure type: Severe
Minimum cement content: 320 kg/m^3
Workability: 75mm slump
Method of concrete placing: pumping
Type of aggregate: Crushed angular
Maximum cement content: 450 kg/m^3
Chemical admixture : Super plasticizer
Specific gravity of cement: 3.15
Specific gravity of fine aggregate: 2.61
Specific gravity of coarse aggregate: 2.73
Coarse and fine aggregate: Grade 1
Target strength:
f'ck = fck + 1.65s
s = 5 (From table 1 of IS 10262 2009)
f'ck = 35+ (1.65 x 5) = 43.25 N/mm^2
Selection of water cement ratio:
From table 5 IS 456:2000, For severe exposure condition maximum w/c = 0.45
From IS 10262 2019, w/c for target strength 38.25 N/mm^2 = 0.40
Selection of water content:
Maximum water content = 186lit
For 75mm slump, water content = 186 + ((3/100)x186) = 191
Super plasticizer reduces 29% of water content.
Hence new water content = (71/100)x191 = 135.61
Calculating cement content:
Water/cement = 0.4
cement = 135.61/0.4 = 339.025 > 320 kg/m^3
Therefore cement content = 339 kg/m^3
Proportioning of volume of coarse and fine aggregate:
volume of coarse aggregate for w/c 0.38 = 0.624
Since the concrete is pumpable the volume of coarse aggregate is reduced by 10% = 0.624 x 0.9 = 0.56
volume of fine aggregate = 1-0.56 = 0.44
[11:56 pm, 16/09/2022] Amogh: Mix calculations:
- Volume of concrete = 1m^3
- Volume of cement = (Mass of cement/specific gravity)x(1/1000)
(339/3.15)x(1/1000) = 0.107 m^3
- Volume of flash 30% of cement 0.0321 m^3
- Volume of water = (Mass of water/specific gravity)x(1/1000)
= (135.61/1)x(1/1000) = 0.135 m^3
- Super plasticizer is upto 2% of mass of total cementitious content
= (6.78/1.15)x(1/1000) = 0.006 m^3
- Volume of aggregate = a - (b+c+d) = 1- (0.107+0.135+0.006) = 0.752 m^3
- Mass of coarse aggregate = e x volume of coarse aggregate x specific gravity of coarse aggregate
= 0.752x0.56x2.73x1000 = 1150 kg
- Mass of fine aggregate = 0.752 x 0.44 x 2.61*1000
= 863 kg
Mix Proportioning:
Cement = 237.3 kg/m^3
Fly ash = 101.7 kg/m^3
Fine aggregate = 863 kg/m^3
Coarse aggregate = 1150 kg/m^3
W/C = 0.4
Admixture = 7 kg/m^3