Civil Engineering - Estimating and Costing - Discussion

Wet volume of concrete.

Area = 100 m^2.
Thickness = 4 cm = 0.04 m.
Wet volume = 100 × 0.04 = 4.00 m^3
Allowance for uneven surface/base.
Add 10% extra = 4.00 × 1.10 = 4.40 m^3.

Dry volume of concrete.

For concrete work, increase wet volume by 50% (or a factor of 1.5) to account for bulking/voids in dry materials.
Dry volume = 4.40 × 1.5 = 6.60 m^3.

(Some references use 1.54 factor directly on wet volume without the 10% step, giving ≈6.16 m^3, but the 10% + 50% combination is common in many exam/estimation contexts and yields 6.6 m^3.)
Proportion of cement in 1:2:4 mix.
Total parts = 1 + 2 + 4 = 7 parts.
Cement proportion = 1/7.

Volume of cement.
Cement quantity = Dry volume × (1/7) = 6.60 × (1/7) ≈ 0.942 m^3 ≈ 0.94 m^3.

Area = 100 sq.m.
Thk= 4 cm = 0.04 m.
V=A*Thickness = 100 * 0.04 = 4 cu.m.
Extra increase for dry volume = 1.55 * 4 = 6.20 cu.m.
Qty of cement in(1:2:4) = 6.20* 1/(1+2+4) = 0.88 cu.m.

Area =100 m^2.

Thickness = 4cm
= 0.04M
Volume = 100 * 0.04
= 4M^3
The Volume of cement = dry volume/sum of the ratio.
= 1.54/1+2+4
= 0.22 M^3
For 4 m^3 = 0.22*4.
= 0.88M^3.
So ,0.90m^3 is the right answer.

Area = 100 M2.
Thickness = 4 cm = 0.04m.
Volume = 100*0.04 = 4 M3.
Add 54% of Dry vol = 4+ 54/100 * 4 = 6.16 m3.
Cement = 1/7 *6.16 = 0.88 m3.

As per my knowledge, the Correct answer is 0.888 cum.

0.88 m^3 is the correct answer.

Yes, correct. Thanks everyone.

Qc = (1.65 * 100* 0.04)*1/7.
Qc = 0.94m^3.

@Raj.

Very well analysis. Thanks.

The volume of concrete= 100 * .04 = 4.
10% increase for the unevenness + 50% increase for dry volume =4*1.1*1.5 = 6.6cum,
Cement=6.6/(1+2+4).