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

Mix design of M 35 grade with fly-ash

Aim- To estimate the concrete mix design for M35 grade concrete with fly ash.

Introduction- The prime purpose is to make concrete as eco-friendly as feasible. To gain the required workability, durability and minimum strength of M35 grade concrete. The following codes for concrete mix design

• IS 10262:2009
• IS 456:2000
• IS 8112
• IS 9103
• IS 3812 (part 1)

The information that we require in this project are-

• Target mean strength : f’ck = fck+1.65s

Where, f’ck = target mean strength

fck = compressive strength at 28 days of concrete

s = standard deviation (IS 10262:2009, Table-1)

• Volume of cement : (mass of cement / specific gravity of cement) × 1/1000
• Volume of water: ( mass of water / specific gravity of water) × 1/1000
• Volume of chemical admixture : mass of chemical admixture/ specific gravity of water) × 1/1000
• Volume of fly ash : ( mass of fly ash / specific gravity of fly ash) × 1/1000
• Volume of concrete : 1m^3
• Volume of aggregates : ( Volume of concrete – ( Volume of cement + Volume of fly ash + Volume of water+ Volume of admixture)
• Mass of coarse aggregates : Volume of aggregate × Volume of coarse aggregates × specific gravity of coarse aggregate × 1000
• Mass of fine aggregate : Volume of aggregate × Volume of fine aggregate × specific gravity of fine aggregate × 1000

Procedure-

Step- 1

Stipulation for proportioning

1. Grade designation: M35
2. Type of cement: OPC 43 grade confirming to IS 8112
3. Type of mineral admixture: Fly ash confirming to IS 3812 (part-1)
4. Maximum nominal size of aggregate : 20 mm
5. Minimum cement content: 320Kg/m^3 (Table:5 IS 456:2000, based on exposure condition)
6. Maximum water cement ratio: 0.45 (Table:5 IS 456:2000, based on exposure condition)
7. Workability: 100mm slump value of pumpable concrete
8. Exposure condition: Severe (Reinforced concrete)
9. Procedure of concrete placing: Pumping
10. Degree of supervision: Good
11. Type of aggregate: Crushed angular aggregate
12. Maximum cement content: 450 Kg/m^3
13. Chemical admixture type: Superplaticizer

Step -2

Test data for materials

1. Cement used: OPC 43 grade confirming to IS 8112
2. Specific gravity of cement: 3.15
3. Fly ash: Confirming to IS 3812 part-1
4. Specific gravity of fly ash: 2.2
5. Chemical admixture: Superplaticizer confirming to IS 9103
6. Specific gravity of

Coarse aggregate: 2.74

Fine aggregate: 2.74

1. Water absorption:

Coarse aggregate: 0.5%

Fine aggregate: 1%

1. Free surface moisture:

Coarse aggregate: Nil

Fine aggregate: Nil

1. Sieve analysis

Coarse aggregates:

IS sieve size (mm)

Fine aggregate: Confirming to grade zone 1 of table 4 IS 383.

Step-3

To find target mean strength of mix proportioning

Target mean strength f’ck = fck+1.65s

= 35+1.65*5 = 43.25 N/m^2

fck = Characteristic compressive strength

s = Standard deviation

Step-4

Selection of water-cement ratio

Maximum water cement ratio = 0.45 (for severe condition, from table 5 of IS 456:2000

On experience water cement ratio = 0.40

0.4<0.45, Hence, ok.

Step-5

Calculation of water content

Maximum water content for 20mm aggregate = 186 litres (Table 2 of IS: 10262:2009) for 25mm to 50mm slump range for 100mm slump = 186+(6/100)*186= 197 litres.

As superplaticizer is utilized, the water content is decreased upto 30%

Depend on trials water content depletion of 29% is gained with plasticizer

Hence, appeared water content = 197*0.71 = 140 litres.

Step-6

Calculation of cement content

Water cement ratio of 0.40

Cementatious material (cement + fly ash) = 140/0.4 = 350 Kg/m^3

In table 5 of IS 456:2000, the cement content for severe exposure = 320 Kg/m^3

350 Kg/m^3 > 320 Kg/m^3

Hence, ok.

To proportion the mix holding fly-ash the following steps are required-

1. The percentage of fly-ash require to be determined depend on project need and quality materials.
2. In some cases raise in cementatious material can be notified. Raise in cementatious material content and its percentage may be depend on experience or trial

In this raise of 10% cementatious material content is examined.

Cementatious material content = 350*1.1 = 385 Kg/m^3

Water content = 140 Kg/m^3

So, water-cement ratio = 140/385 = 0.364

Fly ash at 30% total cementatious material content = 35-30% = 115 Kg/m^3

Cement (OPC) = 385-115 = 270 Kg/m^3

Saving of cement while using fly-ash = 350-270 = 80 Kg/m^3

Fly ash being utilized = 115 Kg/m^3

Step -7

Proportion of volume of coarse aggregate and fine aggregate

From table-3 of IS 10262:2009, Volume of coarse aggregate similar to 20 mm size aggregate and fine aggregate (Zone-1) for water-cement ratio = 0.60

In this case the water-cement ratio is 0.40

Hence, the volume of coarse aggregate requires to be raised to reduce the fine aggregate content.

As the water-cement ratio is decreased by 0.10, the portion of volume of coarse aggregate is raised by 0.02 (at the rate of +/- 0.01 for every +/- 0.05 change in water-cement ratio)

Hence, the rectified value of coarse aggregate for the water-cement ratio = 0.64

(If coarse aggregate is not of angular type, then also the volume of coarse aggregate may be needed to be raised properly, depend on experience)

For pumpable concrete, these are decreased by 10%

Volume of coarse aggregate = 0.64*0.90 = 0.576

Volume of fine aggregate = 1-0.576 = 0.424

Step-8

Mix calculations

Mix calculation per unit volume of concrete-

1. Volume of concrete = 1m^3
2. Volume of cement = (Mass of cement / specific gravity of cement)*1/1000

= (270/3.15)*1/1000 = 0.086 m^3

1. Volume of fly ash = (Mass of fly-ash/ specific gravity of fly-ash)*1/1000

= (115/2.2)*1/1000 = 0.052 m^3

1. Volume of water = (Mass of water / specific gravity of water)*1/1000

= (140/1)*1/1000 = 0.140 m^3

1. Volume of chemical admixture = (Mass of admixture/ specific gravity of admixture)*1/1000

= (7.6/1.14)*1/1000= 0.006 m^3

1. Volume of aggregate (Fine and coarse) = a-(b+c+d+e)

= 1-(0.086+0.052+0.140+0.006) = 0.716 m^3

1. Mass of coarse aggregate = f*Volume of coarse aggregate * specific gravity of coarse aggregate*1000

= 0.716*0.576*2.74*1000 = 1130 Kg/m^3

1. Mass of fine aggregate = f*Volume of fine aggregate*specific gravity of fine aggregate*1000

= 0.716*0.424*2.74*1000= 831 Kg/m^3

Step-9

Mix proportion

Cement = 270 Kg/m^3

Fly ash = 115 Kg/m^3

Water = 140 Kg/m^3

Fine aggregate = 831 Kg/m^3

Coarse aggregate = 1130 Kg/m^3

Chemical admixture = 7 Kg/m^3

Water-cement ratio = 0.364

Mix-ratio = 1:2.15:2.94

Step-10

The slump shall be determined and the water content and dosage of admixture shall be rearranged for gaining the needed slump on trial. The mix proportion shall be reworked for the real water content and examined for durability needs.

Step-11

Two or more trials having difference of 10 % water-cement ratio in clause 10 (Step 10) shall be supported out and a graph between three water-cement ratios and similar strengths shall be plotted to work out the mix proportions for the identified target strength for field trials. However, durability shall be reached.

Result-

• The mix design of M35 concrete grade of concrete with fly-ash is 1:2.15:2.94
• This trail mix ratio should match the workability, durability, minimum strength of M35 grade of concrete.
• If it does not assure the above criteria two or more trails for raise of 10% should be done.

Mix design of M 50 grade without fly-ash

Aim- To estimate the concrete mix design for M50 grade concrete without fly-ash.

Introduction- The prime purpose is to make concrete as eco-friendly as feasible. To gain the required workability, durability and minimum strength of M50 grade concrete. The following codes for concrete mix design

• IS 10262:2009
• IS 456:2000
• IS 8112
• IS 9103
• IS 3812 (part 1)

The information that we require in this project are-

• Target mean strength : f’ck = fck+1.65s

Where, f’ck = target mean strength

fck = compressive strength at 28 days of concrete

s = standard deviation (IS 10262:2009, Table-1)

• Volume of cement : (mass of cement / specific gravity of cement) × 1/1000
• Volume of water: ( mass of water / specific gravity of water) × 1/1000
• Volume of chemical admixture : mass of chemical admixture/ specific gravity of water) × 1/1000
• Volume of fly ash : ( mass of fly ash / specific gravity of fly ash) × 1/1000
• Volume of concrete : 1m^3
• Volume of aggregates : ( Volume of concrete – ( Volume of cement + Volume of fly ash + Volume of water+ Volume of admixture)
• Mass of coarse aggregates : Volume of aggregate × Volume of coarse aggregates × specific gravity of coarse aggregate × 1000
• Mass of fine aggregate : Volume of aggregate × Volume of fine aggregate × specific gravity of fine aggregate × 1000

Procedure-

Step- 1

Stipulation for proportioning

1. Grade designation: M50
2. Type of cement: OPC 43 grade confirming to IS 8112
3. Type of mineral admixture: Fly ash confirming to IS 3812 (part-1)
4. Maximum nominal size of aggregate : 20 mm
5. Minimum cement content: 320Kg/m^3 (Table:5 IS 456:2000, based on exposure condition)
6. Maximum water cement ratio: 0.45 (Table:5 IS 456:2000, based on exposure condition)
7. Workability: 100mm slump value of pumpable concrete
8. Exposure condition: Severe (Reinforced concrete)
9. Procedure of concrete placing: Pumping
10. Degree of supervision: Good
11. Type of aggregate: Crushed angular aggregate
12. Maximum cement content: 450 Kg/m^3
13. Chemical admixture type: Superplaticizer

Step -2

Test data for materials

1. Cement utilized: OPC 43 grade confirming to IS 8112
2. Specific gravity of cement: 3.15
3. Chemical admixture: Superplaticizer confirming to IS 9103
4. Specific gravity of

Coarse aggregate: 2.74

Fine aggregate: 2.74

1. Water absorption:

Coarse aggregate: 0.5%

Fine aggregate: 1%

1. Free surface moisture:

Coarse aggregate: Nil

Fine aggregate: Nil

1. Sieve analysis

Coarse aggregates:

IS sieve size (mm)

Fine aggregate: Confirming to grade zone 1 of table 4 IS 383.

Step-3

To find target mean strength of mix proportioning

Target mean strength, f’ck = fck+1.65s

= 50+1.65*5 = 58.25 N/m^2

fck = Characteristic compressive strength

s = Standard deviation

Step-4

Selection of water-cement ratio

Maximum water cement ratio = 0.45 (for severe condition, from table 5 of IS 456:2000

On experience water cement ratio = 0.40

0.4<0.45, Hence, ok.

Step-5

Calculation of water content

Maximum water content for 20mm aggregate = 186 litres (Table 2 of IS: 10262:2009) for 25mm to 50mm slump vary for 100mm slump = 186+ (6/100)*186= 197 litres.

As superplaticizer is utilized, the water content is decreased upto 30%

Depend on trials water content depletion of 29% is gained with plasticizer

Hence, appeared water content = 197*0.71 = 140 litres.

Step-6

Calculation of cement content

Water cement ratio of 0.40

Cementatious material (cement + fly ash) = 140/0.4 = 350 Kg/m^3

In table 5 of IS 456:2000, the cement content for severe exposure = 320 Kg/m^3

350 Kg/m^3 > 320 Kg/m^3

Hence, ok.

Step -7

Proportion of volume of coarse aggregate and fine aggregate

From table-3 of IS 10262:2009, Volume of coarse aggregate corresponding to 20 mm size aggregate and fine aggregate (Zone-1) for water-cement ratio = 0.60

In this case the water-cement ratio is 0.40

Hence, the volume of coarse aggregate requires to be raised to reduce the fine aggregate content.

As the water-cement ratio is reduced by 0.10, the portion of volume of coarse aggregate is raised by 0.02 (at the rate of +/- 0.01 for every +/- 0.05 change in water-cement ratio)

Hence, the rectified value of coarse aggregate for the water-cement ratio = 0.64

(If coarse aggregate is not of angular type, then also the volume of coarse aggregate may be needed to be raised properly, depend on experience)

For pumpable concrete, these are decreased by 10%

Volume of coarse aggregate = 0.64*0.90 = 0.576

Volume of fine aggregate = 1-0.576 = 0.424

Step-8

Mix calculations

Mix calculation per unit volume of concrete-

1. Volume of concrete = 1m^3
2. Volume of cement = (Mass of cement / specific gravity of cement)*1/1000

= (350/3.15)*1/1000 = 0.111 m^3

1. Volume of water = (Mass of water / specific gravity of water)*1/1000

= (140/1)*1/1000 = 0.140 m^3

1. Volume of chemical admixture = (Mass of admixture/ specific gravity of admixture)*1/1000

= (7.6/1.145)*1/1000= 0.006 m^3

1. Volume of aggregate (Fine and coarse) = a-(b+c+d)

= 1-(0.111+0.140+0.006) = 0.743 m^3

1. Mass of coarse aggregate = f*Volume of coarse aggregate * specific gravity of coarse aggregate*1000

= 0.743*0.576*2.74*1000 = 1173 Kg/m^3

1. Mass of fine aggregate = e*Volume of fine aggregate*specific gravity of fine aggregate*1000

= 0.743*0.424*2.74*1000= 863 Kg/m^3

Step-9

Mix proportion

Cement = 350 Kg/m^3

Water = 140 Kg/m^3

Fine aggregate = 863 Kg/m^3

Coarse aggregate = 1173 Kg/m^3

Chemical admixture = 7 Kg/m^3

Water-cement ratio = 0.4

Mix-ratio = 1:2.46:3.35

Step-10

The slump shall be determined and the water content and dosage of admixture shall be rearranged for gaining the needed slump on trial. The mix proportion shall be reworked for the real water content and examined for durability needs.

Step-11

Two or more trials having difference of 10 % water-cement ratio in clause 10 (Step 10) shall be supported out and a graph between three water-cement ratios and similar strengths shall be plotted to work out the mix proportions for the identified target strength for field trials. However, durability shall be reached.

Result-

• The mix design of M50 concrete grade of concrete with fly-ash is 1:2.46:3.35.
• This trail mix ratio should match the workability, durability, minimum strength of M50 grade of concrete.
• If it does not assure the above criteria two or more trails for raise of 10% should be done.