Concrete is a composite material of cement, fine sand, coarse aggregate, and water
In this article, we learn how to calculate the quantity of cement, sand, and coarse aggregates of a design mix. Below is the examples, which explain the procedure:
Manual Calculation
Calculate the approximate quantity of cement, fine sand, and coarse aggregates to prepare 1 cum of “1:1.5:3Concrete”
Data
Concrete ratio = 1:1.5:3
Concrete volume = 1 cum
As we know the Volume of dry Concrete = is 1.55 to 1.57 times the volume of wet concrete
So total volume of required concrete will be= 1 x 1.56=1.56 cum (Assume factor as 1.56)
Calculation
Concrete Ratio = 1: 1.5: 3 Means;
Cement is in ratio 1
Fine sand is in a ratio 1.5
And coarse aggregate is in ratio 3
So total ratio will be = 1+1.5+3 = 5.5
Quantity of Cement
Quantity of Cement = Ratio of cement x volume of dry concrete / Total ratio
= 1 x 1.56 / 5.5
=0.284 cum
Unit weight of cement = 1400 ~ 1500 kg/cum (Assume 1450kg/cum)
1cum of cement = 1450kg
Quantity of cement= 0.284 x 1450 = 412kg
1 cement beg = 50 kg
No of cement begs required = 412 / 50 =8.24 ~ 8 begs
Quantity of Fine sand
Quantity of fine sand = Ratio of fine sand x volume of dry concrete / Total ratio
= 1.5 x 1.56 / 5.5
=0.425 cum
Unit weight of Fine sand = 1600 ~ 1800 kg/cum (Assume 1700 kg/cum)
Quantity of Fine sand= 0.425 x 1700 =722.5 kg
Quantity of Coarse aggregates
Quantity of coarse aggregate = Ratio of coarse aggregates x volume of dry concrete / Total ratio
= 3 x 1.56 / 5.5
=0.851 cum
Unit weight of coarse aggregate = 1500 ~ 1800 kg/cum (Assume 1650 kg/cum)
Quantity of coarse aggregates= 0.851 x 1650 =1404 kg
Amount of Water Required
The water-cement ratio depends upon the strength, climatic factors, and workability requirement of concrete.
Cement required for 1 cum of concrete = 412Kg
Assume w/c ratio = 0.50 Water required for 1 cum of concrete. = 412 x 0.5
Amount of Water Required for 1 cum of concrete = 206 kg = 206 liters
Summary
So, for a 1:1.5:3 concrete, we would need approximately:
- 8 bags of cement
- 0.425 cum of fine sand
- 0.851 cum of coarse aggregate
- 206 liters of water
Note: Please note that this calculation is approximate and can vary depending on the properties of the used materials and applicable standards in the specific region.
Automatic Calculation
Below, you can find the automatic calculator for quantity estimation, simply input values and get the result. Here a:b: c is the design concrete ratio input as 1:1.5:3 or 1:2:4 etc.
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