Role of Water in Concrete
Water is the most important & least expensive ingredient of concrete.
It plays an important role in mixing, laying, compaction, setting & hardening of concrete.
The strength of concrete depends on the quality & quantity of water used in the mix. The functions of water in the concrete mix are given below:
1. It acts as a lubricant for the fine and coarse aggregate & makes the mixture workable.
2. It acts chemically with cement to form the binding paste.
3. It is employed to damp the aggregate surface in order to prevent them from absorbing water vitally necessary for chemical action.
4. It facilitates the spreading of aggregate.
5. It helps to flux the cementing material over the surface of the aggregate.
6. It enables the concrete mix to flow into moulds.
Quality Of Mixing Water In Concrete
The water to be used for preparing the concrete should fulfil the following requirement.
1. It should be fresh & clean.
2. It should be free from organic impurities injurious amounts of acids or alkalies, hygroscopic, greasy & oily substance.
3. It should be free from iron, vegetable matter, or any other substance which is likely to have an adverse effect on concrete or reinforcement.
4. It should be fit for drinking purpose.
5. The PH value shall generally be between 6 and 8.