Project on Concrete Mix Design for various grades of Concrete

1. Aim: Calculate the Grade of M35 Mix design of concrete with flyash

Steps in concrete mix design as per IS 10262-2019

1. Stipulation for proportioning
2. Test data for materials
3. Target strength for mix proportioning
4. Approximate air content
5. Selection of water cement ratio
6. Selection of water content
7. Calculation of cement and flyash content
8. Proportion of volume of coarse aggregate and fine aggregate content
9. Mix calculation
10. Mix proportion for trial #1

1. stipulation for proportioning

1. Grade design : M35
2. Type of cement : 43 grade OPC confirming to IS 269-2015
3. Types of mineral

admixture : Flyash

1. Maximum nominal size

of coarse aggregate : 20mm

1. Exposure condition : Extreme RCC work
2. Workability : 100 mm slump
3. Method of concrete placing: Pumping
4. Degree of supervision: Good
5. Types of aggregate : Crushed angle aggregate
6. Chemical mixture type: Superplasticiser normal

2. Test data for material

1. Cement used : 43 grade OPC confirming to IS 8112
2. Specific gravity of cement : 15
3. Specific gravity : 145
4. Chemical Admixtures : Super plasticizer conforming to IS 9013-1999)
5. Flyash : Conforming of Is 3812 (Part 1) – 2013
6. Specific gravity of Fly ash : 2
7. Specific gravity of

• Coarse aggregate 20mm : 78
• Fine aggregate : 68 percentage

1. water absorption in right condition to absorb the water of

• Coarse aggregate 20mm : 45 %
• Fine aggregate : 1% (For saturated surface

dry condition)

1. The coarse and fine aggregate are wet and their total moisture content is 2% and 5% respectively therefore the free moisture content in coarse aggregate fine aggregate
2. Coarse aggregate

Free moisture = Total moisture content - water absorption

= (2.0 – 0.45 + 0.55) / 2

= 1.5%

Fine aggregate

Free moisture = Total moisture content – water absorption

= 0.5 – 1.0

= 4.0%

1. Coarse Aggregate : Conforming to table 7 IS 383 – 2016

Fine Aggregate : Conforming to Grading zone II table 9 IS 383 –

2016

3. Target Mean Strength for Proportioning

F’_ck = F_ck + 1.65 S

Or

F’_ck = F_ck + X

Table 1 Value of X (Cl 4.2)

Grade of concrete : M35

Value of X : 6.5

Table 2 Assumed standard deviation (Cl 4.2.1.3)

Grade of concrete : M35

Assumed standard deviation N/mm² : 5.0

F’_ck = F_ck + 1.65 S = 35 + 1.65 x 5 = 43.25N/mm²

F’_ck = F_ck + X = 35 + 6.5 = 41.5N/mm²

4. Approximate Air content:

From Table 3 IS 456 – 2019, Approximate air content (Cl 5.2) of entrapped air to be expected in normal (Non air- entrained) concrete is 1.0 percent for 20mm nominal maximum size of aggregate.

5. Selection of water cement ratio:

From graph 2

Free W/C ration required for the target Strength of 43.25N/mm² is 0.36 may be used for OPC 43 grade / PPC curve 2

W/C ratio = 0.36 (From strength criteria)

Durability = W/C ratio = 0.36<0.45 hence O.K

Conforming table 5 (Cl 6.1.2, 8.2.4.1 and 9.1.2)

Minimum cement content Kg/m³ = 320Kg/m³

Maximum free W/C ratio = 0.38

6. selection of water content

Table 4 of IS 10262 2019 maximum water content for 20mm aggregate = 186 litre (for 25mm to 50mm slump range) but for an increase by about 3% every additional 25mm slump

So here estimated water content for 100 slump

186+ 6/100 x 186

Water required = 197.16 litre

Based on trials with superplasticiser water content reduction of 25 % has been achieved at the rate of 1.0% by weight of cement

net water required is equal to 197.16× 25% = 49.29%

= 197.16 – 49.29 = 147.87 litre

7. Calculation of cement and flash content

As discussed earlier adopted based on trial water cement ratio = 0.36

Cement content 156.24/0.36 = 422.27kg/m³ hence ok

Cementitious content = 422.27 kg/m³

Additional off percentage flyash depends upon project required under quality of flyash. Increase in cementitious material content is also permitted based on trial and experience

IS 456-2000 (Cl 8.2.4.2 maximum cement content)

Let us increase cementitious material content by 10%

Cementitious material content = 422.27x1.10 = 464.49 kg/m³ = 464kg/m³

New cementitious material = 464 kg/m³

So water cement ratio = 156.24/464 = 0.336

35% will be replaced with flyash

Flyash = 0.35 x 464.97 = 162.73 kg/m³

Cement = 464.49 – 162.73 =301.76kg/m³

From Table 5 off IS 456 minimum cementitious content for severe exposure condition is 320 kg/m³ hence ok.

584 kg/m³ > 320 kg/m³ hands ok

8. Proportion of volume of course aggregate and fine aggregate

As per table 5 of IS 10262-2009 volume of course aggregate 420mm nominal size aggregate and fine aggregate (zone III)

1. 62

In the present case water cement ratio 0.336 therefore volume of course aggregate is required to the increased to decrease the fine aggregate content as the water cement lower by 0.236 the proportion of volume of course aggregate is increased by 0.012 (at the rate of -/+ 0.01 for every ± 0.05 change in water cement ratio

= (0.341/0.05) = 6.82 times of 0.01

0.01 x 6.82 = 0.0682

1. 0.0682

a + b = 0.62 + 0.0.682 = 0.6882 at the grade of -/+ 0.01 for every ± 0.05 changing water cement ratio

as per IS 10262-2009

Therefore corrected proportion of volume of course aggregate for the water cement ratio of 0.341 is 0.6882

For pumpable concrete this value should be reduced up to 10% therefore volume of course aggregate = 0.6882 x 0.9 = 0.61

Volume of fine aggregate content = 1 - 0.61 = 0.39

9. Mix calculation

Mix calculation per unit volume of content is as follow

1. Volume of concrete = 1m³
2. Volume of entrapped air in wet concrete is equal to 0.01 m³
3. Volume of cement = (Mass of cement) / {specific gravity of cement) x 1000}

= 301.76 / {3.15 x1000} = 0.0958m³

2. Based on trial we had kept chemical mixtures one 2.2% by weight of cement

=1x 464 / 100 = 10.21 kg/m³

Volume of admixtures= Mass of admixture) / {specific gravity of admixture x 1000}

=10.21 {1.145x1000}

= 0.0089m³

1. Volume of water = mass of water]/ {specific gravity of water x 1000}

=147.87 / {1x1000} = 0.147m³

1. Volume of all in aggregate [(a + b) + (c + d + e)]

= [(0.09) + (0.0740 + 0.156 + 0.0089)

= 0.328m³

1. Mass of course aggregate = (g) volume of course aggregate x specific

gravity of course aggregate x 1000

= (0.672 x 0.5994) x 2.78 x 1000

= 1087.55 kg/m³

1. mass of fine aggregate = (g) volume of fine aggregate x specific gravity of

fine aggregate x 1000

= 0.672 x 0.40 x 2.68 x 1000

= 701.56 kg/m³

10. Mixed proportion for trial #1

Cement : 301 kg/m³

Flyash : 162.73 kg/m³

Water net mixing : 156.24 kg/m³ (or) 154 litre

Fine aggregate : 701.56 kg/m³

Coarse aggregate : 1167.56 kg/m³

Chemical admixtures : 10.21 kg/m³ (or) 10.21 litre

Free water cementitious material ratio : 0.38

2. Calculate the Grade of M50 Mix design of concrete without flyash

Steps in concrete mix design as per IS 10262-2019

1. Stipulation for proportioning
2. Test data for materials
3. Target strength for mix proportioning
4. Approximate air content
5. Selection of water cement ratio
6. Selection of water content
7. Calculation of cement and flyash content
8. Proportion of volume of coarse aggregate and fine aggregate content
9. Mix calculation

• Mix proportion for trial #1

1. stipulation for proportioning

1. Grade design : M50
2. Type of cement : 43 grade OPC confirming to IS 269-2015
3. Types of mineral

admixture : nil

1. Maximum nominal size

of coarse aggregate : 20mm

1. Exposure condition : Severe RCC work
2. Workability : 125 mm slump
3. Method of concrete placing: Pumping
4. Degree of supervision: Good
5. Types of aggregate : Crushed angle aggregate
6. Chemical mixture type: Superplasticiser normal

2. Test data for material

1. Cement used : 43 grade OPC confirming to IS8112
2. Specific gravity of cement : 15
3. Specific gravity : 145
4. Chemical Admixtures : Sika (Sikament 170 (H) Super

plasticizer conforming to IS 9013-1999)

1. Specific gravity of

• Coarse aggregate 20mm : 78
• Coarse aggregate 10mm : 78
• (Combined the specific gravity of aggregate (20mm 60% and 10mm 40%) : 78 percentage confirming 2

Table 2 IS 383

• Fine aggregate : 68 percentage

1. water absorption in right condition to absorb the water of

• Coarse aggregate 20mm : 45 %
• Coarse aggregate 10mm : 55 %
• Fine aggregate : 1% (For saturated surface

dry condition)

1. The coarse and fine aggregate are wet and their total moisture content is 2% and 5% respectively therefore the free moisture content in coarse aggregate fine aggregate
2. Coarse aggregate

Free moisture = Total moisture content - water absorption

= (2.0 – 0.45 + 0.55) / 2

= 1.5%

Fine aggregate

Free moisture = Total moisture content – water absorption

= 0.5 – 1.0

= 4.0%

1. Coarse Aggregate : Conforming to table 7 IS 383 – 2016

Fine Aggregate : Conforming to Grading zone II table 9 IS 383 –

2016

3. Target Mean Strength for Proportioning

F’_ck = F_ck + 1.65 S

Or

F’_ck = F_ck + X

Table 1 Value of X (Cl 4.2)

Grade of concrete : M50

Value of X : 6.5

Table 2 Assumed standard deviation (Cl 4.2.1.3)

Grade of concrete : M50

Assumed standard deviation N/mm² : 5.0

F’_ck = F_ck + 1.65 S = 50 + 1.65 x 5 = 58.25N/mm²

F’_ck = F_ck + X = 50 + 6.5 = 56.5N/mm²

4. Approximate Air content:

From Table 3 IS 456 – 2019, Approximate air content (Cl 5.2) of entrapped air to be expected in normal (Non air- entrained) concrete is 1.0 percent for 20mm nominal maximum size of aggregate.

5. Selection of water cement ratio:

From graph 2

Free W/C ration required for the target Strength of 58.25N/mm² is 0.29 may be used for OPC 43 grade / PPC curve 2

W/C ratio = 0.29 (From strength criteria)

Durability = W/C ratio = 0.29<0.45 hence O.K

Conforming table 5 (Cl 6.1.2, 8.2.4.1 and 9.1.2)

Minimum cement content Kg/m³ = 320Kg/m³

Maximum free W/C ratio = 0.45

6. selection of water content

Table 4 of IS 10262 2019 maximum water content for 20mm aggregate = 186 litre (for 25mm to 50mm slump range) but for an increase by about 3% every additional 25mm slump

So here estimated water content for 125 slump

186+ 9/100 x 186

Water required = 202 litre

Based on trials with superplasticiser water content reduction of 23.76 % has been achieved at the rate of 1.0% by weight of cement

net water required is equal to 202× 23.76% = 48%

= 202 – 48 = 154 litre

7. Calculation of cement and flash content

As discussed earlier adopted based on trial water cement ratio = 0.29

Cement content 154/0.29 = 531 kg/m³ hence ok

Cementitious content a polymer531

Additional off percentage flyash depends upon project required under quality of flyash. Increase in cementitious material content is also permitted based on trial and experience

Let us increase cementitious material content by 10%

Cementitious material content = 531x1.10 = 584.1 kg/m³ = 584kg/m³

New cementitious material = 583 kg/m³

So water cement ratio = 154/584 = 0.264

From Table 5 off IS 456 minimum cementitious content for severe exposure condition is 320 kg/m³ hence ok.

584 kg/m³ > 320 kg/m³ hands ok

8. Proportion of volume of course aggregate and fine aggregate

As per table 5 of IS 10262-2009 volume of course aggregate 420mm nominal size aggregate and fine aggregate (zone II) for having water cement ratio of 0.50 is 0.60

1. 60

In the present case water cement ratio 0.264 therefore volume of course aggregate is required to the increased to decrease the fine aggregate content as the water cement lower by 0.236 the proportion of volume of course aggregate is increased by 0.012 (at the rate of -/+ 0.01 for every ± 0.05 change in water cement ratio

= (0.236/0.05) = 4.72 times of 0.01

0.01 x 4.72 = 0.0472

1. 0.0472

a + b = 0.62 + 0.0472 = 0.6672 at the grade of -/+ 0.01 for every ± 0.05 changing water cement ratio

as per IS 10262-2009

Therefore corrected proportion of volume of course aggregate for the water cement ratio of 0.264 is 0.6672

For pumpable concrete this value should be reduced up to 10% therefore volume of course aggregate = 0.6672 x 0.9 = 0.60

Volume of fine aggregate content = 1 - 0.60 = 0.46

9. Mix calculation

Mix calculation per unit volume of content is as follow

1. Volume of concrete = 1m³
2. Volume of entrapped air in wet concrete is equal to 0.01 m³
3. Volume of cement = (Mass of cement) / {specific gravity of cement) x 1000}

= 409 / {3.15 x1000} = 0.1298m³

1. Based on trial we had kept chemical mixtures one 1% by weight of cement

=1x 584 / 100 = 5.84 kg/m³

Volume of admixtures= Mass of admixture) / {specific gravity of admixture x 1000}

=5.84 {1.145x1000}

= 0.0051m³

1. Volume of water = mass of water]/ {specific gravity of water x 1000}

=154 / {1x1000} = 0.154m³

1. Volume of all in aggregate [(a - b) - (c + d + e + f)]

= [(1-0.01) – (0.129 + 0.795 + 0.0051 + 0.154)

= 0.99 – 3.3684

= 0.6216m³

1. Mass of course aggregate = (g) volume of course aggregate x specific

gravity of course aggregate x 1000

= (0.6216 x 0.60) x 2.78 x 1000

= 1167.56 kg/m³

1. mass of fine aggregate = (g) volume of fine aggregate x specific gravity of

fine aggregate x 1000

= 0.6216 x 0.40 x 2.68 x 1000

= 666.36 kg/m³

10. Mixed proportion for trial #1

Cement : 409 kg/m³

Water net mixing : 154 kg/m³ (or) 154 litre

Fine aggregate SSD : 666.36 kg/m³

Coarse aggregate SSD : 1167.56 kg/m³

Chemical admixtures : 5.84 kg/m³ (or) 5.1 litre

Free water cementitious material ratio : 0.264

adjustment of water fine aggregate and coarse aggregate (if the coarse aggregate and fine aggregate is in wet condition)

1. fine aggregate (wet)

Mass of wet fine aggregate

= Mass of fine aggregate in SSD condition x ( 1 + free (surface) moisture/100)

= 666.36 x (1 + 4/100) = 693.014 kg/m³

= 693 kg/m³

1. coarse aggregate (wet)

mass of wet coarse aggregate

= mass of course aggregate in SSD condition x (1 + free (surface) moisture/100)

=116.56 x (1+1.5/100)

= 1185.07 kg/m³

=1185 kg/m³

The quality of this water is required to be subtracted from the calculated water content

1. Water content contributed by wet fine aggregate

= mass of wet fine aggregate - mass of SSD condition fine aggregate

= 693 – 666.36 = 26.64 kg

2. Water content contributed by wet coarse aggregate

= Mass of wet coarse aggregate mass of SSD condition course aggregate = 1185 - 1167.56 = 17.44 kg

The requirement for added water becomes:

= 154 – 26.64 – 17.44 kg

= 109.92 kg

= 110 kg

Mixed proportion after adjustment wet aggregates:

Cement : 409 kg/m³

Water to be added : 110 kg/m³ (or) 110 litre

Fine aggregate wet : 693 kg/m³

Coarse aggregate wet : 1185 kg/m³

Chemical admixtures : 5.84 kg/m³ (or) 5.1 litre

Free water cementitious material ratio : 0.264