What is water cement ratio?
The ratio between the weight of water to the weight of cement in the concrete mix is called Water Cement (W/C) ratio.
How to calculate the quantity of water for Concrete?
Normally, the water cement ratio being between 0.4 to 0.6 as per IS standard.
We take 0.42 as a ratio of W/C.
Quantity of water = 0.42 x 50 = 21 Liters (1 bag cement = 50 Kg)
So the required quantity of water is 21 Liters per cement bag.
M15 Ratio 1:2:4
cement = 317 Kg (unit weight = 1440 kg/cum)
Sand = 638 Kg (unit weight = 1450 Kg/cum)
Blue Metal = 1478 Kg (unit weight = 1680 Kg/Cum)
Total = 316.8+638+1478 = 2433 Kg
unit weight of Water = 1000 Kg
Water ratio = 1000/2433 = 0.41
By this method you can calculate the water-cement ratio for concrete.