In the construction cement, sand and aggregate quantity calculation.
Length of slab – 1m
Width of slab – 1m
Thickness of slab – 0.125 m
Grade of concrete – M15 (1 cement: 2 sand: 4 aggregate)
Step:1 – Calculate volume of slab
Volume of slab = L x B x Thickness = 1 x 1x 0.125 = 0.125 cumt
This is wet volume = 0.125 cumt
Step:2 – Calculate Dry volume
Dry volume – Dry volume is total volume of dry materials (cement, sand, aggregate) without added water.
When dry volume is calculated typically adds certain percentage to nominal volume to account for void spaces between the particles of the concrete materials.
To calculate dry volume add 52 to 54 percentage added.
Wet volume – Wet volume is the volume of the material after added water into concrete materials.
The wet volume is the less than dry volume because after added water some voids are fills.
Dry volume of concrete – 1.54 x wet volume (Here we considered 54% of wet volume)
= 1.54 * 0.125 = 0.1925 cumt
Step:3 – Calculate volume of cement:
Volume of cement – Ratio of cement / Total Ratio X Dry Volume
= 1/(1+2+4)X 0.1925
= 1/7 x 0.1925
= 0.0275 cumt
No of cement bags = Volume of cement / Volume of 1 Kg cement bag
Volume of 1 cement bag = 0.0353 cumt
No of cement bags = 0.275 / 0.0353
= 7.79 ~ 8 bags
Step:4 – Calculate volume of Sand:
Volume of sand – Ratio of sand / Total Ratio X Dry Volume
= 2/(1+2+4)X 0.1925
= 2/7 x 0.1925
= 0.055 cumt
Step:5 – Calculate volume of Aggregate:
Volume of sand – Ratio of Aggregate / Total Ratio X Dry Volume
= 4/(1+2+4)X 0.1925
= 4/7 x 0.1925
= 0.11 cumt
So, Final Cement, sand, aggregate quantity required for slab:
Cement = 8 bags
Sand = 0.055 cumt
Aggregate = 0.11 cumt
