How to Calculate Cement, Sand, Aggregate Quantity of Concrete

 CONCRETE CALCULATION

Cement, Sand, and Aggregate Quantity

 

 

Slab on grade

 

Floor slab size: 10'-0" x 10'-0" x 0'-6"

 

Volume → 50 cft

 

Wet volume of concrete: 50 cft

 

Dry volume of concrete = ?

 

The dry volume of concrete = 1.54 x The wet volume of concrete.

 

Wet concrete is composed of cement, fine aggregate, coarse aggregate, and water.

 

 

 

 

 

 

Dry volume of concrete

Dry concrete is composed of cement, fine aggregate, and coarse aggregate.

 

Void Ratio Compressibility of materials used in 1 m3 of concrete

Coarse Aggregate = 32%

Fine Aggregate =20%

Cement is neglected (due to fine particles).

Wastage = 2–10% (we take 2%)

Total void ratio = 32 + 20 + 2 = 54%

 

 

The percentage of voids caused by cement is 10%.

The percentage of voids caused by fine aggregate is 12%.

The percentage of voids caused by coarse aggregate is 32%.

The total percentage of voids is 54%.

 

So, we  need 100%

= (100/100)+(54/100) =1+0.54 =1.54

 

 

 

Dry volume of concrete = 50 X 1.54

                                       =77 cft

M20 -  1 : 1.5 : 3  →  1+1.5+3 = 5.5

 

 

 

Cement:

 

 1 bag cement (50 kg)    = 1.25 cft

 

Cement    =  1 / 5.5 x 77  =  14 cft

 

                 = 14/1.25      = 11.2 Bag

 

 

Fine Aggregate:

 

100 cft = 1 Unit

 

Sand         =  1.5 / 5.5 x 77  =  21 cft

 

                 = 21/100           = 0.21 unit      ¼ unit

 

 

 

Coarse Aggregate:

 

100 cft = 1 Unit

 

         =  3 / 5.5 x 77  =  42 cft

 

                 = 42/100           = 0.42 unit      ½ unit

 

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Calculate Cement, Sand, Aggregate Quantity of Concrete