Introduction: How the Theory Evolved and How It Impacts Practice
Complex physical phenomena usually have a long history, must draw on many fields of science, and have a multifaceted practical impact. The creep, shrinkage, moisture diffusion, and thermal effects in concrete are an excellent example. This brief chapter highlights the main historical advances, beginning in 1887. It introduces the reader to the general problematics and breadth of the present complex phenomenon and points out diverse creep, moisture, and thermal effects on practical concrete structures, not only negative but also positive. Additionally, recognizing that various concrete structures have very different levels of sensitivity to these effects, the present chapter discerns five different structure types requiring different levels of sophistication in design calculations, depending on the practical impact. They range from simple and crude quasi-elastic estimates to computations based on experimentally verified theory of greater, though inevitable, complexity.