Shrinkage of concrete occurs mainly in the cement paste. To limit shrinkage, both the water and the cement content should be kept as low as possible without compromising its placing and finishing ability, strength or durability. The water reduction using these admixtures should also allow cement content to be reduced while still achieving the required concrete strength class.
Dispertion of the admixture throughout the concrete is key to the performance of the concrete. Incorrect use and inadequate mixing can lead to variable concrete setting characteristics and poor performance.
Water reducing admixtures are typically dosed at 0.30 to 0.7 litres per 100kg of cement and give water reductions of up to 30% without reducing consistence.
It is recommended that the water reducing admixture is specifically designed for floor application.