Project on Concrete Mix Design for various grades of Concrete

Mix design for m35 grade concrete - 

1)Grade - M35

Max size of aggregate  = 20mm

Min cement content - 340 kg/m^3 (table 5 IS 456:2000)

Max water cement ratio - 0.45 (Table 5 IS 456:2000)

Workability - 100-120 mm slump 

Method of concrete placing = Pumping

Degree of supervision = good

type of aggregate - crushed angular aggregate 

max cement content - 390 kg/m^3 

Chemical admixture - superplasticizer

Sp. gravity of cement - 3.15

Sp. gravity of fine aggregate - 2.64

Sp. gravity of coarse aggregate - 2.84

1) Determining the target mean strength 

ft = fck + 1.65 x S 

ft = 35 + 1.65 x 5 = 43.25 N/mm^2

2) Selection of water cement ratio - 

max water cement ratio = 0.45 

based on experience, adopted water cement ratio = 0.40

0.40<0.45. Hence, ok

3) selection of water content -

for 20mm size aggregate, 186 litres of water is used 

for 100mm slump, estimated water content = 186 + (6/100) x 186 = 197 litres

for every 25 mm slump, 3% can be added to the value . therefor 6% for 100 mm slump

based on trials, 20% water reduction can be achieved by superplasticizer

therefore arrived water content = 197 - (197 x (20/100)) = 157 litres.

4) Selection of cement content

adopted water cement ratio is 0.40 

cement content = 157/0.40 = 395 kg/m^3

395>340kg/m^3 (from table 5 IS 456)