Project on Concrete Mix Design for various grades of Concrete

Calculate the Concrete Mix Design for M35 grade concrete with fly ash & M50 grade concrete without Fly ash

AIM: To calculate the concrete mix design for M35 grade concrete with flyash

Objectives:

• To achieve desired workability,durability,minimum strength for M35 grade of concrete
• To produse the concrete as ecnomical

Code for concrete mix design

• IS 10262:2009
• IS 456:2000
• IS 8112
• IS 9103

Procedure and Caluculation:

1.TARGET STRENGTH

f’ck =fck + 1.65s

where as

f’ck = target average compressive strength at 28 days

fck = characteristics compressive strength at 28 days

s = standard deviation.

From Table I of IS 10262:2009 Standard Deviation s = 5 N/mm²

Therefore, target strength = 35 + 1.65 x 5 = 43.25 N/mm²

As the super plasticizer is used, the water content can be reduced upto 20% and above.Based on trials with Super plasticizer

water content reduction of 20% has been achieved, Hence the arrived water content = 186*0.80 = 149 litre.

4.CALCULATION OF CEMENT CONTENT

water cement ratio = 0.4

Cement Content = 149/0.4 = 370 kg/m³

From Table 5 of IS 456, Minimum cement content for ‘Extreme’ exposure conditions 360kg/m³

370 kg/m³ > 360 kg/m³ hence ok.

Increased by 10 percentage=370+0.1*370=407 kg/m3

Water cement ratio=149/407=0.366

Fly ash at 30 % total cementious material content=407*0.3=122 kg/m3

cement =407-122=285 kg/m3

Fly ash=122 kg/m3

5.VOLUME OF COARSE AGGREGATE AND FINE AGGREGATE CONTENT

• From Table 3 of (IS 10262:2009) Volume of coarse aggregate corresponding to 20 mm size aggregate and fine aggregate
• (Zone I) for volume of CA=0.60 .
• In the present case water-cement ratio is 0.4. Therefore, volume of coarse aggregate is required to be increased to decrease the fine aggregate content.
• As the water-cement ratio is lower by 0.10. The proportion of volume of coarse aggregate is increased by 0.02 (at the rate of -/+ 0.01 for every ± 0.05 change in water-cement ratio).
• corrected proportion of volume of coarse aggregate for the water-cement ratio = 0.62

6. MIX CALCULATIONS

The mix calculations per unit volume of concrete shall be as follows:
a) Volume of concrete = 1 m³

b) Volume of cement = Mass of cement / (Specific Gravity of Cement*1000)= 385/(3.15 x 1000)=0.090 m3

c) Volume of fly ash =Mass of fly ash /(Specific gravity of fly ash *1000)=122/(2.2*1000)=0.055m3

d) Volume of water = Mass of water/ (Specific Gravity of water x 1000)= 149/(1 x 1000)= 0.149m³

e) Volume of chemical admixture = Mass of chemical admixture /(specific gravity of chemical

admixture*1000)=7.6/(1.145*1000)=0.006 m3

f) Volume of CA&FA aggregate = [a-(b+c+d+e)]= [1-(0.090+0.055+0.149+0.006)]= 0.7m³

g) Mass of coarse aggregate= e x Volume of Coarse Aggregate x Specific Gravity of Fine Aggregate x 1000

= 0.7x 0.62 x2.74 x 1000= 1189.16 kg/m³

g) Mass of fine aggregate= e x Volume of Fine Aggregate x Specific Gravity of Fine Aggregate x 1000

= 0.7x 0.38x 2.74 x 1000= 728 kg/m³

7. MIX PROPORTIONS

Cement = 285 kg/m3

Fly ash =122 kg/m3

Water = 149 Kg/m3

Coarse aggregate = 1189.16 kg/m3

Fine aggregate = 728 kg/m3

Chemical admixture = 7.6 kg/m3

Water-cement ratio = 0.366

Trial Mix Ratio= 1:2.55:4.17(C:FA:CA)

M50 grade concrete without Fly ash

AIM: To calculate the concrete mix design for M50 grade concrete without flyash

Objectives:

• To achieve desired workability,durability,minimum strength for M50 grade of concrete
• To produse the concrete as ecnomical

Code for concrete mix design

• IS 10262:2009
• IS 456:2000
• IS 8112
• IS 9103

Procedure and Caluculation:

1.TARGET STRENGTH

f’ck =fck + 1.65s

where as

f’ck = target average compressive strength at 28 days

fck = characteristics compressive strength at 28 days

s = standard deviation.

From Table I of IS 10262:2009 Standard Deviation s = 5 N/mm²

Therefore, target strength = 50 + 1.65 x 5 = 58.25 N/mm²

As the super plasticizer is used, the water content can be reduced upto 20% and above.Based on trials with Super plasticizer

water content reduction of 20% has been achieved, Hence the arrived water content = 186*0.80 = 149 litre.

4.CALCULATION OF CEMENT CONTENT

water cement ratio = 0.4

Cement Content = 149/0.4 = 373 kg/m³

From Table 5 of IS 456, Minimum cement content for ‘Extreme’ exposure conditions 360kg/m³

373 kg/m³ > 360 kg/m³ hence ok.

5.VOLUME OF COARSE AGGREGATE AND FINE AGGREGATE CONTENT

• From Table 3 of (IS 10262:2009) Volume of coarse aggregate corresponding to 20 mm size aggregate and fine aggregate
• (Zone I) for volume of CA=0.60 .
• In the present case water-cement ratio is 0.4. Therefore, volume of coarse aggregate is required to be increased to decrease the fine aggregate content.
• As the water-cement ratio is lower by 0.10. The proportion of volume of coarse aggregate is increased by 0.02 (at the rate of -/+ 0.01 for every ± 0.05 change in water-cement ratio).
• corrected proportion of volume of coarse aggregate for the water-cement ratio = 0.62

6. MIX CALCULATIONS

The mix calculations per unit volume of concrete shall be as follows:
a) Volume of concrete = 1 m³

b) Volume of cement = Mass of cement / (Specific Gravity of Cement*1000)= 373/(3.15 x 1000)=0.118 m3

c) Volume of water = Mass of water/ (Specific Gravity of water x 1000)= 149/(1 x 1000)= 0.149m³

d) Volume of chemical admixture = Mass of chemical admixture /(specific gravity of chemical

admixture*1000)=7.6/(1.145*1000)=0.006 m3

f) Volume of CA&FA aggregate = [a-(b+c+d)]= [1-(0.118+0.149+0.006)]= 0.727m³

g) Mass of coarse aggregate= e x Volume of Coarse Aggregate x Specific Gravity of Fine Aggregate x 1000

= 0.727x 0.62 x2.74 x 1000= 1235.02 kg/m³

g) Mass of fine aggregate= e x Volume of Fine Aggregate x Specific Gravity of Fine Aggregate x 1000

= 0.727x 0.38x 2.74 x 1000= 756.9 kg/m³

7. MIX PROPORTIONS

Cement = 373 kg/m3

Water = 149 Kg/m3

Coarse aggregate = 1235.02 kg/m3

Fine aggregate = 756.9 kg/m3

Chemical admixture = 7.6 kg/m3

Water-cement ratio = 0.4

Trial Mix Ratio= 1:2.02:3.31(C:FA:CA)