Duff A. Abrams stated the water/cement ratio law as: "For a given cement and conventional aggregates in workable mixtures, under similar conditions of placement, curing and test, the strength of concrete is solely a function of the ration of cement to the free water in the plastic mixture." And in comparing concrete made with aggregates, water, and cement that are absolutely uniform and in which aggregate gradation and volume are unvarying, few would challenge the applicability of the water/cement ratio. However, unvarying materials for concrete are practically impossible to achieve in the laboratory, let alone in the field. Even the manner in which concrete ingredients are introduced into the mix, the type of drum used, the mixing time, ambient and materials temperatures will all have a bearing on the important performance characteristics that will be developed by the concrete. Even if the potential strengths of two concrete mixes were exactly the same and they were delivered to two different job sites, it is most unlikely that they would develop the same strengths in place. This is due to variations in transporting, placing and curing of the concrete. Although the water/cement ratio acknowledges the role these factors play in strength development, many practitioners applying the pronouncement fail to take note of them. Much more than in any other phase of construction, quality in concrete depends on intelligent, informed cooperation by all members of the construction team. The architect must know the characteristics of the material; the engineer must use enlightened design practices; the contractor must be informed in the proper concrete construction practices and ready mixed concrete producer must provide concrete of the required strength. Even the owner must do his part by anticipating current and projected needs and by providing adequate maintenance.