Water reducer

Water reducers are special chemical products added to a concrete mixture before it is poured. They are from the same family of products as retarders. Water reducers offer several advantages in their use, listed below:
 * reduces water content by 5-10%
 * increases concrete strength by up to 25% (as less water is required for the concrete mixture to remain workable)
 * increased workability (assuming the amount of free water remains constant)
 * reduced permeability (due to less water being used)
 * better finish (due to all of the above)