What is the minimum water cement ratio required to complete chemical reaction in a concrete mix ?

Minimum water cement ratio's necessary for hydration of cement range is from 0.19 to the mid-twenties (i.e.0.26). The additional water added to cement, sand and rock beyond that needed for hydration of the cement is water added for convenience. This means we need a certain amount of extra water in the mix to get the workability needed for placement and finishing. This extra water in the mix that is not used in hydration remains throughout the cement paste to evaporate at some later time. Higher water-Cement ratios cause the cement paste to become more porous. The more porous the cement paste, the weaker and less durable the concrete.

about0.24