Water

Water is an important ingredient of concrete as it actively participates in the chemical reaction with cement. This hydration of cement results in strength giving cement gel. While a lot of emphasis is laid on quantity of water to be added, the quality of water is  taken for granted, most of the times. 

A popular yard stick is that water fit for  drinking i.e. potable water is fit for making concrete. As a site engineer see that : 

• A proper storage is provided for  water for construction 
• The water used by workers for  their cleaning, washing etc. should not be mixed with water for construction. 
• Water should be got tested for its chemical impurities and checked with specifications laid down in IS: 456. 
• In case of doubt, make concrete cubes with water  under examination and test them and compare results with similar cubes prepared with water known to be suitable. 
• Avoid use of sea water for construction, specially in case of prestressed concrete.