Project on Concrete Mix Design for various grades of Concrete
1) Concrete Mix Design for M35 grade concrete with fly ash :
AIM :
To calculate the Concrete Mix Design for M35 grade concrete with fly ash.
Introduction:
The Mix design calculation of M35 Grade Concrete with Fly ash admixture and super plasticizer as per Indian Standard Codebook IS10262(2009) – Guidelines for Concrete Mix Proportioning.
Procedure:
Mix proportioning of concrete using fly ash as part of replacement of OPC
1. STIPULATIONS FOR PROPORTIONING OF M35 GRADE CONCRETE :
- Grade Designation : M35
- Type of Cement : OPC 53
- Type of Admixture : Fly ash
- Maximum Nominal Size of Aggregate : 20mm
- Type of aggregate: Crushed granular aggregate
- Minimum Cement Content : 340Kg/m^3 (Table 5-IS456)
- Maximum Cement Content : 450 Kg/m^3 (as per code)
- Maximum W/C ratio : 0.45 (Table 5-IS456)
- Workability : 100mm
- Chemical Admixture : superplasticizer
2. TEST DATA FOR MATERIALS :
1.Cement Used : OPC 53 (Confirming to IS8112)
2.Specific Gravity of Cement : 3.15 (Test – IS: 2720)
3.Mineral Admixture : Fly ash (Confirming to IS12089)
4.Specific Gravity of Fly ash : 2.90
5.Chemical Admixture : @0.6% IS9103
6.Specific Gravity of Test – IS 2386
- Coarse Aggregate : 2.7
- Fine Aggregate : 2.74
- Admixture PCE based : 1.12
Water Absorption Test – IS 2386
- Coarse aggregate : 0.5 %
- Fine aggregate : 1 %
8.Sieve Analysis Test – IS 2386
- Coarse aggregate: Confirming to Table 2-IS383
- Fine aggregate : Zone II (Confirming to Table 4-IS383)
3. TARGET STRENGTH FOR MIX PROPORTIONS OF M35 GRADE CONCRETE :
Fck = fck+1.65*S
From table 1 of IS 10262:2009, Standard deviation S= 5 N/mm^2
fck = 35 N/mm^2
Fck = 35+1.65*5
Target strength = 43.25 N/mm^2
4. Selection of water-cement ratio:
The maximum water-cement ratios for different grades of concrete are given in Table 5-IS456.
The water-cement ratio directly affects the strength of the concrete.
Maximum W/C ratio = 0.45
Adopted W/C ratio = 0.45
5. Selection of water content:
Maximum Water Content = 180 L
The water content above is for a slump of 25 to 50 mm, but according to the specification our concrete requires a slump of 100 mm. Therefore, to get the desired slump, the water content must be increased. Clause 4.2 of IS1026 recommends increasing the water content by 3% to obtain an additional 25 mm slump. Therefore, to obtain a slump of 50 mm in addition to our concrete, the water content must be increased by 6%.
Water-content for 100mm Slump = 186+(6/100)*186
= 197 L
As Superplasticizer is used, the water content can be reduced upto 30%.Based on trails water content reduction of 20% is achieved with plasticiser.
Water content requirement after SP = 198 – (0.20*198)
= 160 L
6. Calculation of cement content:
Water-cement ratio = 0.45
Cementitious material (cement+fly ash) content = 160/0.45 = 355.55 Kg/m^3
From table 5 of IS 456 minimum cement content for 'severe' exposure condition = 320 Kg/m^3
356Kg/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 = 356*1.10 = 391.6 Kg/m^3
Water content = 160 Kg/m^3
Fly ash @ 30% total cementitious material content = 391.6*0.30 = 1117.48 ~ 118 Kg/m^3
Cement (OPC) = 385-117.48 = 274.12 ~ 275 Kg/m^3
Cement saving while using the fly ash = 350-275= 75 Kg/m^3
Fly ash being util = 118Kg/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 20 mm size aggregate and fine aggregate (Zone 2) for water-cement ratio of 0.50 = 0.60
In the present case the w/c ratio is 0.5
Therefore, In the 0.5 w/c ratio will be 0.62 volume aggregates
Coarse aggregate ratio for 0.45 w/c ratio will be 0.63 (adding 0.01 for every decrease 0.5 and vice versa)
Final fine aggregate ratio = (1-0.63) = 0.37
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 = 275/3.15 * 1/1000 = 0.087 m^3
c) Volume of cement = Mass of fly ash/Specific gravity of fly ash * 1/1000 = 118/2.5 * 1/1000 = 0.041m^3
d) Volume of water = Mass of water/Specific gravity of water * 1/1000 = 160/1 * 1/1000 = 0.160 m^3
e) Volume of Superplasticizer @ 6% by the mass of cementitious material = 391.6*(0.6/100) /1.145 * 1/1000
= 0.002 m^3
f) Volume of all in aggregate = a-(b+c+d+e) = 1-(0.087 +0.041+0.160+0.002)= 0.71 m^3
g) Mass of Coarse aggregate = f*Volume of coarse aggregate*Specific gravity of CA*1000 = 0.71*0.63 *2.74 *1000 = 1225.6 Kg/m^3
h) Mass of fine aggregate = f*Volume of fine aggregate*Specific gravity of FA*1000 = 0.71*0.37*2.74 *1000 =719.8 Kg/m^3
9. Mix weight of materials in concrete or result:
| S.No. | Materials | Quantity |
| 1 | Cement | 275Kg/m^3 |
| 2 | Flyash | 118Kg/m^3 |
| 3 | Fine Aggregate | 720Kg/m^3 |
| 4 | Coarse Aggregate (20mm) | 1226Kg/m^3 |
| 5 | WATER | 160 L |
| 6 | PCE based SuperPlasticizer | 2 L |
The Trail mix ratio : 1:1.83:3.11
2) Concrete Mix Design for M50 grade concrete without fly ash :
AIM :
To calculate the Concrete Mix Design for M50 grade concrete without fly ash.
Introduction:
The Mix design calculation of M50 Grade Concrete without Fly ash admixture and super plasticizer as per Indian Standard Codebook IS10262(2009) – Guidelines for Concrete Mix Proportioning.
Procedure:
Mix proportioning of concrete using fly ash as part of replacement of OPC
1. STIPULATIONS FOR PROPORTIONING OF M35 GRADE CONCRETE :
- Grade Designation : M35
- Type of Cement : OPC 53
- Maximum Nominal Size of Aggregate : 20mm
- Type of aggregate: Crushed granular aggregate
- Minimum Cement Content : 340Kg/m^3 (Table 5-IS456)
- Maximum Cement Content : 450 Kg/m^3 (as per code)
- Maximum W/C ratio : 0.45 (Table 5-IS456)
- Workability : 100mm
- Chemical Admixture : superplasticizer
2. TEST DATA FOR MATERIALS :
1.Cement Used : OPC 53 (Confirming to IS8112)
2.Specific Gravity of Cement : 3.15 (Test – IS: 2720)
3.Chemical Admixture : @0.6% IS9103
4.Specific Gravity of Test – IS 2386
- Coarse Aggregate : 2.7
- Fine Aggregate : 2.74
- Admixture PCE based : 1.12
Water Absorption Test – IS 2386
- Coarse aggregate : 0.5 %
- Fine aggregate : 1 %
8.Sieve Analysis Test – IS 2386
- Coarse aggregate: Confirming to Table 2-IS383
- Fine aggregate : Zone II (Confirming to Table 4-IS383)
3. TARGET STRENGTH FOR MIX PROPORTIONS OF M35 GRADE CONCRETE :
Fck = fck+1.65*S
From table 1 of IS 10262:2009, Standard deviation S= 5 N/mm^2
fck = 50N/mm^2
Fck = 50+1.65*5
Target strength = 58.25 N/mm^2
4. Selection of water-cement ratio:
The maximum water-cement ratios for different grades of concrete are given in Table 5-IS456.
The water-cement ratio directly affects the strength of the concrete.
Maximum W/C ratio = 0.45
Adopted W/C ratio = 0.45
5. Selection of water content:
Maximum Water Content = 180 L
The water content above is for a slump of 25 to 50 mm, but according to the specification our concrete requires a slump of 100 mm. Therefore, to get the desired slump, the water content must be increased. Clause 4.2 of IS1026 recommends increasing the water content by 3% to obtain an additional 25 mm slump. Therefore, to obtain a slump of 50 mm in addition to our concrete, the water content must be increased by 6%.
Water-content for 100mm Slump = 186+(6/100)*186
= 197 L
As Superplasticizer is used, the water content can be reduced upto 30%.Based on trails water content reduction of 20% is achieved with plasticiser.
Water content requirement after SP = 198 – (0.20*198)
= 160 L
6. Calculation of cement content:
Water-cement ratio = 0.45
Cementitious material (cement+fly ash) content = 160/0.45 = 355.55 Kg/m^3
From table 5 of IS 456 minimum cement content for 'severe' exposure condition = 320 Kg/m^3
356Kg/m^3 > 320Kg/m^3, Hence OK
Cementitious material content = 356 Kg/m^3
Water content = 160 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 20 mm size aggregate and fine aggregate (Zone 2) for water-cement ratio of 0.50 = 0.60
In the present case the w/c ratio is 0.5
Therefore, In the 0.5 w/c ratio will be 0.62 volume aggregates
Coarse aggregate ratio for 0.45 w/c ratio will be 0.63 (adding 0.01 for every decrease 0.5 and vice versa)
Final fine aggregate ratio = (1-0.63) = 0.37
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 = 356/3.15 * 1/1000 = 0.113 m^3
c) Volume of water = Mass of water/Specific gravity of water * 1/1000 = 160/1 * 1/1000 = 0.160 m^3
d) Volume of Superplasticizer @ 6% by the mass of cementitious material = 356*(0.6/100) /1.145 * 1/1000
= 0.002 m^3
e) Volume of all in aggregate = a-(b+c+d) = 1-(0.113+0.160+0.002)= 0.725 m^3
f) Mass of Coarse aggregate = e*Volume of coarse aggregate*Specific gravity of CA*1000 = 0.725*0.63 *2.74 *1000 = 1251.4 Kg/m^3
g) Mass of fine aggregate = e*Volume of fine aggregate*Specific gravity of FA*1000 = 0.725*0.37*2.74 *1000 =735 Kg/m^3
9. Mix weight of materials in concrete or result:
|
S.No. |
Materials |
Quantity |
|
1 |
Cement |
356Kg/m^3 |
|
2 |
Fine Aggregate |
735Kg/m^3 |
|
3 |
Coarse Aggregate (20mm) |
1251Kg/m^3 |
|
4 |
WATER |
160 L |
|
5 |
PCE based SuperPlasticizer |
2 L |
The Trail mix ratio : 1:2.06:3.51