Concrete construction involves two phases which correspond to the areas of responsibility of the producer and contractor. The production phase belongs to the ready mixed producer. He is to be responsible for securing satisfactory ingredient materials, combining them in proper proportions, mixing them in to a homogeneous product and delivering the mixture into the hands of the contractor in such a condition that it can be satisfactorily placed. The contractor is responsible for the second phase. This includes the movement of the concrete into the forms, its proper placement and consolidation, the finishing operations, and adequate protection and curing to assure developing the quality potential. Transfer of the concrete from the producer's delivery truck into the handling equipment of the contractor marks the division between the two areas of responsibility. However, there is some overlap. One example is the practice of adding extra water at the job site. The contractor should inform his work force that this is not a good practice and firmly discipline workers who are trying to avoid high slump. On the same hand, the ready mix producer should insist that water over the amount needed in obtaining a desired slump be signed for.