Construction Building Envelope and Interior Finishes Databook

Concrete is an ancient material of construction, first used during the Roman Empire, which extended from about 20 B.C. to 200 A.D. The word concrete is derived from the Roman concretus, meaning to grow together. Although this early mixture was made with lime, cement, and a volcanic ash material called pozzolana, concrete today is a sophisticated material to which exotic constitutents can be added and, with computer-controlled batching, can produce a product capable of achieving 50,000 psi compressive strength.
The factors contributing to a successful batch of concrete are
Precise measurement of water content;
Type, size, and amount of cement and aggregate;
Type, size, and location of reinforcement within the concrete pour to compensate for the lack of tensile strength basic in concrete;
Proper curing procedures during normal hot or cold weather conditions.