Project on Concrete Mix Design for various grades of Concrete
1) Calculate the Concrete Mix Design for M35 grade concrete with fly ash
Aim:
To calculate the concrete mix design proportioning for M35 grade concrete with fly ash replacing of cement.
Introduction:
The concrete mix design of M35 graded concrete with replacing the fly ash designate with using of several code books in IS standards for taking the grade and quantity of cement, exposure condition, water-cement ratio, workability of concrete and the properties of fly ash etc. Datas collected from the given IS code books. The design mix for the concrete will be good strength, workability and the quality of the concrete will improves. Design mixes using to the large construction sites i.e., Bridges, Dams etc. and the quality of construction also improves.
Procedure:
Mix proportioning of concrete using fly ash as part of replacement of OPC.
1. Stipulation for proportioning:
- Grade designation: M35
- Type of cement: OPC 43 grade conforming to IS 8112.
- Type of mineral admixture: Fly ash conforming to IS 3812 (Part-1)
- Maximum nominal size of aggregate: 20mm
- Minimum cement content: 320Kg/m^3 (From table 5 of IS 456:2000 - Exposure condition)
- Maximum water-cement ratio: 0.45 (From table 5 of IS 456:2000 - Exposure condition)
- Workability: 100mm (Slump value of pumpable concrete)
- Exposure condition: Severe (For reinforced concrete)
- Method of concrete placing: Pumping
- Degree of supervision: Good
- Type of aggregate: Crushed granular aggregate
- Manimum cement content: 450Kg/m^3
- Chemical admixture: Superpalsticizer
2. Test data for materials:
- Cement used: OPC 43 grade conforming to IS 8112.
- Specific gravity of cement: 3.15
- Fly ash: conforming to IS 3812 (Part-1)
- Specific gravity of fly ash: 2.2
- Chemical admixture: Superpalsticizer conforming to IS 9103
Specific gravity of:
CA: 2.74
FA: 2.74
Water absorption:
CA: 0.5%
FA: 1.0%
Sieve analysis:
CA: Conforming to table 2 of IS 383
FA: Conforming to grading Zone 1 of table 4 of IS 383
3. Target mean strength for mix proportioning:
f'ck = fck+1.65*S
From table 1 of IS 10262:2009, Standard deviation S= 5 N/mm^2
fck = 35 N/mm^2
Therefore, Target strength = 35+1.65*5 = 43.25 N/mm^2
4. Selection of water-cement ratio:
From, Table 5 of IS 456:2000 for severe exposure, maximum water-cement ratio = 0.45
By the based on experience, adopt water-cement ratio as 0.40 0.40 < 0.45 Hence OK
5. Selection of water content:
From, Table 2 of IS 10262:2009, maximum water-content for 20mm aggregate = 186 litres (for 25mm to 50mm slump range)
Estimated water content for 100mm slump = 186+(6/100)*186 = 197 litres
As Superplasticizer is used, the water content can be reduced upto 30%
Based on trails water content reduction of 29% is achieved with plasticizer.
Hence, the arrived water content, 100-29 = 71%
= 197*(71/100) = 140 litre or kg
6. Calculation of cement content:
Water-cement ratio = 0.40
Cementitious material (cement+fly ash) content = 140/0.40 = 350 Kg/m^3
From table 5 of IS 456 minimum cement content for 'severe' exposure condition = 320 Kg/m^3
350Kg/m^3 > 320Kg/m^3, Hence OK
Assume the percentage of fly ash to be needed in the project 30%
Increase the cementitious material content is 10% for trail and experience basis
cementitious material content = 350*1.10 = 385 Kg/m^3
Water content = 140 Kg/m^3
So, water-cement ratio = 385/140 = 0.364
Fly ash @ 30% total cementitious material content = 385*0.30 = 115 Kg/m^3
Cement (OPC) = 385-115 = 270 Kg/m^3
Cement saving while using the fly ash = 350-270 = 80 Kg/m^3
Fly ash being utilized = 115 Kg/m^3
7. Proportion of volume of coarse aggregate and fine aggregate content:
From table 3 of IS 10262:2009, volume coarse aggregate corresponding to 20mm size aggegate and fine aggregate (Zone 1) for water-cement ratio of 0.50 = 0.60
In the present case the w/c ratio is 0.40
If reduce the w/c ratio 0.1 is equals to the increase in volume of aggregates can be take 0.02
Therefore, In the 0.40 w/c ratio will be 0.62 volume aggregates
If the pumpable concrete is taken means, it will reduce the 10% volume of aggregates
The volume of coarse aggregate = 0.62*0.90 = 0.56
The volume of fine aggregate = 1-0.56 = 0.44
8. Mix calculation:
The mix calculations per unit volume of concrete shall be as follows:
a) Volume of concrete = 1 m^3
b) Volume of cement = Mass of cement/Specific gravity of cement * 1/1000 = 270/3.15 * 1/1000 = 0.086 m^3
c) Volume of cement = Mass of fly ash/Specific gravity of fly ash * 1/1000 = 115/2.2 * 1/1000 = 0.052 m^3
d) Volume of water = Mass of water/Specific gravity of water * 1/1000 = 140/1 * 1/1000 = 0.140 m^3
e) Volume of chemical admixture (Superplasticizer) @ 2% by the mass of cementitious maetrial = 350*0.02/1.145 * 1/1000 = 0.006 m^3
f) Volume of all in aggregate = a-(b+c+d+e) = 1-(0.086+0.052+0.140+0.006) = 0.716 m^3
g) Mass of Coarse aggregate = f*Volume of coarse aggregate*Specific gravity of CA*1000 = 0.716*0.56*2.74*1000 = 1098 Kg/m^3
h) Mass of fine aggregate = f*Volume of fine aggregate*Specific gravity of FA*1000 = 0.716*0.44*2.74*1000 =863 Kg/m^3
9. Mix weight of materials in concrete or result:
Mass of cement = 270 Kg/m^3
Mass of water = 140 Kg/m^3
Mass of fly ash = 115 Kg/m^3
Mass of fine aggregate = 863 Kg/m^3
Mass of coarse aggregate = 1098 Kg/m^3
Mass of fly ash = 115 Kg/m^3
Mass of chemical admixture = 7 Kg/m^3
Water-cement ratio = 0.364
Trail mix ratio: 1:2.24:2.85
2) Calculate the Concrete Mix Design for M50 grade concrete without fly ash
Aim:
To calculate the concrete mix design proportioning for M50 grade concrete without fly ash replacing of cement.
Introduction:
The concrete mix design of M50 graded concrete without replacing the fly ash designate with using of several code books in IS standards for taking the grade and quantity of cement, exposure condition, water-cement ratio, workability of concrete and the properties of fly ash etc. Datas collected from the given IS code books. The design mix for the concrete will be good strength, workability and the quality of the concrete will improves. Design mixes using to the large construction sites i.e., Bridges, Dams etc. and the quality of construction also improves.
Procedure:
Mix proportioning of concrete without fly ash as part of replacement of OPC.
1. Stipulation for proportioning:
- Grade designation: M50
- Type of cement: OPC 43 grade conforming to IS 8112.
- Maximum nominal size of aggregate: 20mm
- Minimum cement content: 320Kg/m^3 (From table 5 of IS 456:2000 - Exposure condition)
- Maximum water-cement ratio: 0.45 (From table 5 of IS 456:2000 - Exposure condition)
- Workability: 100mm (Slump value of pumpable concrete)
- Exposure condition: Severe (For reinforced concrete)
- Method of concrete placing: Pumping
- Degree of supervision: Good
- Type of aggregate: Crushed granular aggregate
- Manimum cement content: 450Kg/m^3
- Chemical admixture: Superpalsticizer
2. Test data for materials:
- Cement used: OPC 43 grade conforming to IS 8112.
- Specific gravity of cement: 3.15
- Chemical admixture: Superpalsticizer conforming to IS 9103
Specific gravity of:
CA: 2.74
FA: 2.74
Water absorption:
CA: 0.5%
FA: 1.0%
Sieve analysis:
CA: Conforming to table 2 of IS 383
FA: Conforming to grading Zone 1 of table 4 of IS 383
3. Target mean strength for mix proportioning:
f'ck = fck+1.65*S
From table 1 of IS 10262:2009, Standard deviation S= 5 N/mm^2
fck = 50 N/mm^2
Therefore, Target strength = 50+1.65*5 = 58.25 N/mm^2
4. Selection of water-cement ratio:
From, Table 5 of IS 456:2000 for severe exposure, maximum water-cement ratio = 0.45
By the based on experience, adopt water-cement ratio as 0.40 0.40 < 0.45 Hence OK
5. Selection of water content:
From, Table 2 of IS 10262:2009, maximum water-content for 20mm aggregate = 186 litres (for 25mm to 50mm slump range)
Estimated water content for 100mm slump = 186+(6/100)*186 = 197 litres
As Superplasticizer is used, the water content can be reduced upto 30%
Based on trails water content reduction of 29% is achieved with plasticizer.
Hence, the arrived water content, 100-29 = 71%
= 197*(71/100) = 140 litre or kg
6. Calculation of cement content:
Water-cement ratio = 0.40
Cementitious material (cement+fly ash) content = 140/0.40 = 350 Kg/m^3
From table 5 of IS 456 minimum cement content for severe exposure condition = 320 Kg/m^3
350Kg/m^3 > 320Kg/m^3, Hence OK
cementitious material content = 350 Kg/m^3
Water content = 140 Kg/m^3
7. Proportion of volume of coarse aggregate and fine aggregate content:
From table 3 of IS 10262:2009, volume coarse aggregate corresponding to 20mm size aggegate and fine aggregate (Zone 1) for water-cement ratio of 0.50 = 0.60
In the present case the w/c ratio is 0.40
If reduce the w/c ratio 0.1 is equals to the increase in volume of aggregates can be take 0.02
Therefore, In the 0.40 w/c ratio will be 0.62 volume aggregates
If the pumpable concrete is taken means, it will reduce the 10%, It means 90% of volume of aggregates to be used in the concrete. 100-10 = 90%
The volume of coarse aggregate = 0.62*0.90 = 0.56
The volume of fine aggregate = 1-0.56 = 0.44
8. Mix calculation:
The mix calculations per unit volume of concrete shall be as follows:
a) Volume of concrete = 1 m^3
b) Volume of cement = Mass of cement/Specific gravity of cement * 1/1000 = 350/3.15 * 1/1000 = 0.111 m^3
c) Volume of water = Mass of water/Specific gravity of water * 1/1000 = 140/1 * 1/1000 = 0.140 m^3
d) Volume of chemical admixture (Superplasticizer) @ 2% by the mass of cementitious maetrial = 350*0.02/1.145 * 1/1000 = 0.006 m^3
e) Volume of all in aggregate = a-(b+c+d+e) = 1-(0.111+0.140+0.006) = 0.743 m^3
f) Mass of Coarse aggregate = e*Volume of coarse aggregate*Specific gravity of CA*1000 = 0.743*0.56*2.74*1000 = 1140 Kg/m^3
g) Mass of fine aggregate = e*Volume of fine aggregate*Specific gravity of FA*1000 = 0.743*0.44*2.74*1000 =896 Kg/m^3
9. Mix weight of materials in concrete or result:
Mass of cement = 350 Kg/m^3
Mass of water = 140 Kg/m^3
Mass of fine aggregate = 896 Kg/m^3
Mass of coarse aggregate = 1140 Kg/m^3
Mass of chemical admixture = 7 Kg/m^3
Water-cement ratio = 0.40
Trail mix ratio: 1:2.56:3.26