Project on Concrete Mix Design for various grades of Concrete

Aim:

The calculation for design mix M35 grade concrete with flyash.

Introduction:

In this Mix design M35 we can see concrete mix proportion.to determine the cement, fine aggregate ,coarse aggregate ,water & admixtures calculation for concrete.

Selection of materials:

• Grade -M35 (Reinforced concrete)
• type of cement -OPC53 grade
• Min size of aggregate - 20mm
• min cement content - 340kg/m3 (from table 5 IS456:2000 ,very severe )
• min W/C ratio - 0.45
• Workability - 110mm
• Exposure condition - Very servere
• method of concrete - Pumping
• Degree of superesion - good
• type of agg - crushed angular agg
• chemical admixture - superplasticizer
• Cement used - OPC 53 grade

Specific gravity of material:

• S.P of cement - 3.15
• Flyash - 2.2
• Coarse agg - 2.74
• fine agg - 2.74
• water - 1
• Admixture - 1.145

Procedure:

Target strength f'ck= fck+1.65 S (fck- compressive strength of concrete , s- standard deviation from table-2 IS10262:2019) f'ck = 35+1.65X5.0

= 43.25 N/mm2

Selection of water/cement ratio: from table5 IS456:2000 for very severe conduction

W/C = 0.45 , 0.40<0.45 ok

Selection of waterr content: from table 2 IS 10262:2019 for 20mm size agg - 186 lit consider for slump -25 to 50mm.so in over mix slump value is 110. each 25mm 3% is added.

=186 X 6% =186+11.16 = 197 literes

As superplasticizer water content is reduce upto 29% = 29-100 = 71%

= 197 X 0.71 =140 lit.

Calculation of cement :

W/C =0.45 Cementitious material (cement+flyash) =140/0.45 = 312 Kg/m3

from table 5 IS 456:2000 340 Kg/m3 for very severe conduction

=312 to 340 kg/m3

Mix containing flyash:

In some case cementitious material cane be increase 10%

Cementitious material = 340 x 1.10 = 374kg/m3

water content =140kg/m3

w/c = 140/374 = 0.37

flyash 30% = 374 x0.30 = 112 kg/m3(flyash used)

cement OPC = 374 - 112 = 262 kg/m3

saving cement = 374- 262 = 112 kg/m3

To find volume of CA & FA agg:

Table 3 of IS 10262:2019 Agg 20mm = 0.50 = 0.60 zone-1 =- 0.01 for every +- 0.05 change in w/c ratio

0.45 = 0.61

pumpable concrete values reduce 10% =100-10 = 90%

volu of CA agg = 0.61x0.90 = 0.55

volu of FA agg = 1-0.55 = 0.45

Mix calculation:

Volume of cement =1m3

volume of cement = mass of cement/s.p of cement X 1/1000

= 262/3.15 x 1/1000 = 0.083m3

Volume of flyash = mass of flyash/s.p of flyash X 1/1000

= 112/2.2 x 1/1000 = 0.050m3

Volume of water = mass 0f water/s.p of water X 1/1000

= 140 /1 x 1/1000 = 0.140m3

Volume of chemical admixture (1% from cementitious material ) = mass of adm/s.p of adm X 1/1000

= 3.74/1.145 X 1/1000 = 0.0032m3

volume of agg = (a-(b+c+d+e))

= (1-(0.083+0.050+0.140+0.0032))

= 0.80m3

mass of fine agg = vol of agg x vol of fine agg x s.p of fine agg x 1000

=0.80 x 0.45 x 2.74 x 1000

= 986kg/m3

mass of coarse agg = vol of agg x vol of coarse agg x s.p of fine agg x 1000

=0.80 x 0.55 x 2.74 x 1000

= 1205kg/m3

mass of chemical = 0.003 x 1.145 x 1000

= 3.44k/m3

Trial mix proportion:

Cement - 262 kg/m3

flyash - 112 kg/m3

water - 140 kg/m3

fine aggregate - 986kg/m3

coarse aggregate - 1205kg/m3

chemical add - 3.44kg/m3

water cement ratio - 0.37

MIX RATIO :- 1:2.64:3.22

2. Design mix - M50

Aim:

The calculation for design mix M50 grade concrete.

Introduction:

In this Mix design M50 we can see concrete mix proportion.to determine the cement, fine aggregate ,coarse aggregate ,water & admixtures calculation for concrete.

Selection of materials:

• Grade -M50 (Reinforced concrete)
• type of cement -OPC53 grade
• Min size of aggregate - 20mm
• min cement content - 360kg/m3 (from table 5 IS456:2000 , Extreme)
• min W/C ratio - 0.40
• Workability - 75mm
• Exposure condition - Extreme
• method of concrete - tailgating
• Degree of superesion - good
• type of agg - crushed angular agg
• chemical admixture - superplasticizer
• Cement used - OPC 53 grade

Specific gravity of material:

• S.P of cement - 3.15
• Coarse agg - 2.74
• fine agg - 2.74
• water - 1
• Admixture - 1.145

Procedure:

Target strength f'ck= fck+1.65 S (fck- compressive strength of concrete , s- standard deviation from table-2 IS10262:2019) f'ck = 50+1.65X5.0

= 58.25 N/mm2

Selection of water/cement ratio: from table5 IS456:2000 for very severe conduction

W/C = 0.40 , 0.40<0.45 ok

Selection of waterr content: from table 2 IS 10262:2019 for 20mm size agg - 186 lit consider for slump -25 to 50mm.so in over mix slump value is 75. each 25mm 3% is added.

=186 X 3% =186+5.58 = 191 literes

As superplasticizer water content is reduce upto 29% = 29-100 = 71%

= 191 X 0.71 =135 lit.

Calculation of cement :

W/C =0.45 Cementitious material (cement+flyash) =135/0.40 = 337Kg/m3

from table 5 IS 456:2000 340 Kg/m3 for very severe conduction

=337 to 360 kg/m3

To find volume of CA & FA agg:

Table 3 of IS 10262:2019 Agg 20mm = 0.50 = 0.60 zone-1 =- 0.01 for every +- 0.05 change in w/c ratio

0.40 = 0.62

volu of CA agg = 0.62

volu of FA agg = 1-0.62 = 0.38

Mix calculation:

Volume of cement =1m3

volume of cement = mass of cement/s.p of cement X 1/1000

= 360/3.15 x 1/1000 = 0.011m3

Volume of water = mass 0f water/s.p of water X 1/1000

= 135 /1 x 1/1000 = 0.135m3

Volume of chemical admixture (1% from cement) = mass of adm/s.p of adm X 1/1000

= 3.60/1.145 X 1/1000 = 0.003m3

volume of agg = (a-(b+c+d))

= (1-(0.011+0.135+0.003))

= 0.85m3

mass of fine agg = vol of agg x vol of fine agg x s.p of fine agg x 1000

=0.85 x 0.38 x 2.74 x 1000

= 885kg/m3

mass of coarse agg = vol of agg x vol of coarse agg x s.p of fine agg x 1000

=0.85 x 0.62 x 2.74 x 1000

= 1443kg/m3

mass of chemical = 0.003 x 1.145 x 1000

= 3.44k/m3

Trial mix proportion:

Cement - 360 kg/m3

water - 135 kg/m3

fine aggregate - 885kg/m3

coarse aggregate - 1443kg/m3

chemical add - 3.44kg/m3

water cement ratio - 0.40

MIX RATIO :- 1:2.45:4.00