Water is the cheapest and most important ingredient of concrete. When water and concrete are mixed, a chemical reaction takes place named hydration. Hydration reaction produces a sticky and thick gel which has a binding property and which bind all aggregate in form of tough and strong material. Thus, cement and water both are responsible for binding all elements of concrete together.
Cement and water are used as per their ratio called Water-Cement Ratio. Water-Cement Ratio is defined as the ratio of the weight of water to the weight of cement. Water/cement ratio as per IS 10262 (2009) for the concrete mix varies from 0.4 to 0.6. 0.7 w/c ratio is also used for pumped concrete. 0.5 w/c ratio indicates, that for every 100 kg of cement, 50 lit. of water is added. With an increase of w/c ratio amount of water is increased.
Water in the ingredient in the concrete that mixes with cement to form what is called a binder. It establishes/increases the bond between the cement, the aggregate and the admixture. Water is also responsible for the process of hydration that leads to the hardening of concrete to form different structures.
This is the ease of ferrying and mixing concrete. It can also be regarded as the fluidity of the concrete. Thanks to Water, concrete can be easily mixed to form the desired mixture. The role of water is to reduce external friction between the concrete and whichever equipment being used to mix it. It will also reduce internal friction between the aggregate and the cement. It is because of the workability facilitated by water that concrete.
Following reasons why high water-cement ratio is not recommended:
Following major reasons why the low water-cement ratio is recommended: