QUANTITY OF CEMENT, SAND, & AGGREGATES FOR 1000 SQ FT SLAB

QUANTITY OF CEMENT, SAND, & AGGREGATES FOR 1000 SQ FT SLAB?

To calculate the quantity of cement, sand, and aggregates required for a flat slab first we need to calculate the volume.

Area of flat slab = 1000 sq.ft =93 sq. m.

The minimum thickness provided for slab is 150mm .( According to IS 456)

150 mm = 0.15 metres

Hence Wet volume = Area of slab x Thickness of slab

Wet volume = 93 x 0.15 = 13.95 cu. m.

To calculate the quantities of materials we need dry volume

Dry volume = Wet volume x 1.54

Check why 1.54 is multiplied with wet volume to get dry volume.

∴ Dry volume = 13.95 x 1.54 = 21.48 cu.m (approximately).

Generally, M20 grade concrete is predominantly used for construction purposes.

M20 = 1: 1.5: 3 (Cement:Sand:Aggregates) = (a:b:c)

QUANTITY OF CEMENT:

Quantity of cement = Dry volume x (a/{a+b+c}

Quantity of cement = Dry volume x (1/{1+1.5+3}) for M20 grade concrete.

= 21.48 x (1/5.5}) = 3.90 cu.m = 3.90 cu.m

We need the quantity of cement in terms of bags.

So by multiplying the quantity of cement with the density of cement, we will the get quantity of cement in terms of kilograms.

Unit weight or Density of cement = 1440 kg/cu.m.

Quantity of cement in kg(s) = 1440 x 3.90 = 5616 kg

We know that 1 cement bag = 50 kgs

∴ No. of cement bags required = 5616/50 kg = 112.32 bags =112 bags.

QUANTITY OF SAND:

Quantity of sand = Dry volume x (b/{a+b+c}

∴ Quantity of sand = Dry volume x (1.5/{1+1.5+3}) for M20 grade concrete.

= 21.48 x (1.5/5.5})  = 5.85 cu.m

QUANTITY OF AGGREGATES:

Quantity of aggregates = Dry volume x (c/{a+b+c}

∴ Quantity of aggregates = Dry volume x (3/{1+1.5+3}) for M20 grade concrete.

= 21.48 x (3/5.5}) = 11.71 cu.m

SUMMARY:

Cement = 112 bags.

Sand = 5.85 cu.m

Aggregates = 11.71 cu.m

Note: ConsiderYield of concrete  as 67% &

Wastages of materials = 2%

You can use the same formula for different mix proportions such as 1:2:4 etc.

Here, we have calculated in cubic meter unit but you can calculate in cubic feet unit.