Question

As regarding the concrete lab, you will be required to fabricate 6 standard concrete
cubes (100 mm) for compression testing.
Mass ratios:
Mix 1 (30 MPa) – 1:2:4 with w/c = 0.6
Specific gravity of materials:
Cement: 3.15
Fine and coarse aggregate: 2.60

Calculate the Quantity of material?

Answer 1

1)First let us calculate the quantity of concrete required.

Volume of 1 concrete cube =0.1 x 0.1 x 0.1

                                       =0.001 Cubic meter

For 6 cubes =0.001 x 6=0.006 Cubic meter

The dry volume will be 54% more than the actual volume required

Hence dry voulme =1.54 X 0.006

                          =0.00924 Cubic meter

Given the ratio =1:2:4

Volume of cement =(0.00924/7) x 1 =0.00132 Cubic meter

Volume of fine aggregate=(0.00924/7) x 2 = 0.00264 Cubic meter

Volume of Coarse aggregate =(0.00924/7) x 4 =0.00528 Cubic meter

Specific gravity of cement = 3.15g/cc =3150kg/cubic meter

weight of cement =0.00132 x 3150 =4.158 Kg

Specific gravity of fine and coarse aggregate =2.6g/cc =2600 Kg/cubic meter

weight of fine aggregate = 0.00264 x 2600 =6.864 kg

Weight of Coarse aggregate = 0.00528 x 2600 =13.728 Kg

weight of water = 0.7 x 4.158 =2.9 kg