Water Cement ratio

 

Introduction :

The compressive strength of concrete is one of the most important properties of concrete which is mainly dependent on mainly on the quality and quantity  of its ingredients. Actually for resisting failure, concrete is dependent on mainly one parameter i.e. water cement ratio (w/c ratio). The morden version of original w/c ratio can be given as :

                For a given cement and acceptable aggregates, the strength that may be developed by workable, properly placed mixture of cement, aggregates and water is influenced by :

a)      Ratio of cement to mixing water;

b)      Ratio of cement to aggregates;

c)       Grading, surface texture, shape, strength and stiffness of aggregates particles ;

d)      Maximum size of aggregates.

 

                In the above it can be further inferred that water/cement ratio primarily affects the strength, whereas other factors indirectly affect the strength of concrete by affecting the water/cement  ratio.

 Water Cement ratio

                It is the ratio of weight of water in the concrete mix to  the weight of cement. The weight of water in concrete mix is does not include the weight of water absorbed by the aggregates.

 

Thus we can write :

 

W/C ratio = Weight of water/ weight of cement

 

For normal concrete W/C ratio lies between 0.35 to 0.6. Thus a water-cement ratio of 0.5 indicate that for one bag of cement (50 kg), we required (0.5 x  50 = 25) 25 liters water.

 

Low water/cement ratio have low concrete quality. That effect the strength of the concrete used for the construction.

 

If a perfect water/cement ratio is used for mixing the concrete its gives the greater strength.

 

durability increases of the structure if water/cement used in perfect mix.

 

The lesser the volume of water in concrete, the higher  will be strength of concrete.

 

Water cement ratio gives the good workability.

 

Water cement ratio is established by the Prof. Abram.