What is water cement ratio ?

Water Cement Ratio (w/c ratio) :-
 water cement ratio is the ratio of the weight of water to weight of cement. it is very neccesary to achive the desired WORKABILITY of concrete.
workability means how ease we use the concrete and it should be easy placed in structure.
Water cement ratio is the impotent factor of durability of concrete. it should be minimum as possible.
Generally Maximum water cement ratio is taken between 0.35 to 0.45 according to IS code 456-2000

 For Nominal Weight aggregate of 20mm, Minimum Cement content, Maximum Water cement ratio and Minimum Grade of concrete for different Exposer are given below :-

According to Environmental conditions water cement ratio is given below :-

Environmental condition                     Max. water cement ratio

(1). Mild                                                        0.45
(2). Moderate                                                0.40
(3). Sever                                                      0.40
(4). Very Sever                                             0.38                    
(5). Extreme                                                  0.35