When concrete strength is consistent from batch to batch, suppliers can reduce their cement costs because they can meet the code requirements with a lower average strength concrete. But to take advantage of this opportunity, the suppliers have to document mix performance with records that show average strength and variations in strength. A computer program from the American Concrete Institute (ACI) makes the job easier.
Water is certainly a necessary ingredient in concrete. However, only about 2 gallons are really needed to hydrate one 94-pound bag of cement.