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.

Grade designed: M35 with 10% of flyash

Type of cement: OPC 43 grad conforming to IS 8112

Maximum nominal size of aggregat: 20mm

Explosure type: Very Severe

Minimum cement content: 340 kg/m^3

Workability: 100mm slump

Method of concrete placing: Pumping

Type of aggregate: Crushed angular

Maximum cement content : 450 kg/m^3

Chemical admixture: Super plasticizer

Specific gravity of cement: 3.15

Specific gravity of fine aggregate: 2.2

Specific gravity of coarse aggregate: 2.61

Coarse and fine aggregate: Grade1

Target strength:

f'ck = fck + 165s

s = 5 (From table 1 of IS 10262 2009)

fck = 35 + (1.65*5) = 43.25 N/mm^2

Selection of water cement ratio:

From table 5 IS 456:2000, For sever exposure condition maximum w/c = 0.45

From IS 10262 2019, w/c for target strength 43.25 N/mm^2 = 0.41

Selection of water content:

Maximum water content = 186 lit

Suer plastisizer reduces 29% of water content.

Hence new water content = (71/100)*197 = 139.87

Calculating cement content:

w/c = 0.41

cement =139.87/0.41 = 341.14kg/m^3

Therefore cement cntent = 341.14kg/m^3

Here cement is replaced by 20% fly ash, therefore increase the total

Cementitious content = 1.10 * 341.14 = 375.25kg/m^3

New water cement ratio = 139.87/375.25 = 0.37

20% of fly ash of cementitious content

Proportioning of the volume of coarse and fine aggrgate:

As per IS: 10262: 2009 table 3, zone II,

Volume of coarse aggregatebfor zone II = 0.62

For w/c 0.5 = 0.62

For w/c 0.39 = ?

X = [((0.5 - 0.36)*0.01)/0.05]

X = 0.022

Volume of coarse aggregate should be reduced by 10%

New volume of fine aggregate = 1 - 0.578 = 0.422

Mix calculation:

Volume of concrete = 1 m^3

Volume of cement = weight of cement/(specific gravity*1000)

= 339.025/(3.15*1000) = 0.197 m^3

Volume of water = weight of water/(specific gravity*1000)

= 135.61/1*1000 = 0.135 m^3