Written By : Engr Sami Ullah (www.civilglobal.com)
what is water cement ratio :
Water cement ratio is the ratio of water and cement by weigh and also by volume used in the preparation of concrete mix.
Water Cement Ratio means the ratio between the weight of water to the weight of cement used in concrete mix. And normally water cement ratio is falls under from 0.4 to 0.6 for normal mix like M10 , M15 to M 25. and we know that water cement is directly affect strength of concrete. Therefore it increase the strength if we used the correct proportion of or decrease it, so it depend on the water cement ratio.
Quantity of water is very necessary for the mixing of concrete.
If the percentage of water use is less then there will not be sufficient quantity of water to cement. It should result in porous and weak concrete. So the good result of concrete mix depends on the water cement ratio.
The water which gives as more workable mix , but it does not vie sound of concrete. In Concrete the use of too much water gives us the results in segregation of aggregates and vies us porous concrete and also low strength and low density of concrete.
When we want to make concrete workable to be place in position for that water is more needed.
If we use a lot of water so it makes concrete workable but the strength can become less , so there for we have to use sufficient water for the concrete. Because quantity of more water can make a concrete weak and also its make segregation during the placement of concrete.
Water cement ration is directly propositional to strength of concrete. When water ratio Is maximum the strength of concrete become decrease. If the water ration is minimum the strength will be increase in Concrete.
Strength of concrete is depends on the strength of cement paste and also in other way, the strength of Concrete increases with cement content and decreases with water content.
There for we have to use limit water which are sufficient for the concrete or cement paste.
In also in concrete too much water result become segregation of the sand, Cement and Aggregate in placing.
Water Cement Ratio Amount
We should take the ratio of water in concrete from 0.45% to 0.60% between this ration we will use the water quantity for the concrete.
Example Of Water Cement Ratio
The batching of concrete has gallons of water for the 900 lbs of cement and the water cement ratio can be calculating by this formula.
R = 8.33 x 45 (gallons) / 900 (lbs)
R = 0.42.
There for the we can put any %age In this formula and you can find out the quantity of water in concrete.
Note: with the above cement ratio formula you can use for concrete mix design, when we keep to adding water to increase the workability. Because the concrete has a lot of fluid materials where the aggregate will be settle down.the water cement ration is directly proportional to the concrete. when we increase the water so it increase workability of concrete. but when we do not use more water so it does not increase the workability of concrete.
A person behind this website and Article writer : Engr Sami Ullah (www.civilglobal.com)