Introduction to Fracture Mechanics of Concrete

Abstract

For modeling of fracture process, linear elastic fracture mechanics is applied when the fracture zone is surrounded by an elastic region that can be characterized by stress intensity factors (for linear case) or J integrals (for nonlinear case). The concept of linear elastic fracture mechanics is unable to predict the actual fracture behavior of concrete because the length of the fracture process zone is equal or proportional to the characteristic length (or material length) and may occupy a larger portion of the cross section of the concrete structural members. It was observed from past research and studies that the characterization of unique value of critical stress intensity factors or J integrals and R curves was not successful for cementitious materials because of concrete cracks throughout the entire fracture zone. Subsequently special treatments were developed to model the fracture process zone in concrete using nonlinear fracture models. In this chapter, an introduction of fracture mechanics applications to concrete-like materials is described. The need of evoking fracture mechanics to model the behavior of concrete materials/structures is also discussed. Finally, organization of the book is outlined.