Concrete Control

Concrete suitable for use in dam construction must have the following characteristics: Strength sufficient to carry the loads and provide a required factor of safety; weight, in the case of gravity dams, to provide safety against sliding and overturning; durability to insure against weathering and erosion; impermeability to prevent water percolation and solution of cementing material; and continuity in order that the structure may act according to assumptions of design. These essentials are controlled by various factors which may be grouped under two headings: First, materials from which the concrete is made, and second, methods of using the materials. Materials available and methods for using them scarcely can be considered separately since one is often dependent on the other, and the design of concrete therefore requires consideration of materials and construction procedure as well as type of structure in which it is to be used. It follows, then, that problems of selecting materials and determining construction procedures and schedules should be considered as problems of design.