Modelling the fracture of cementitious materials

Abstract

The crack band and the fictitious crack line models of the fracture process zone in cementitious materials are discussed. The two methods are quite similar. However, the fictitious crack model is shown to lend itself to a simple K-superposition method which makes use of known analytical expressions. This method is shown to give very similar results to a finite-element analysis of the fictitious crack model and has the advantage that it can be programmed for a personal computer. The predictive capability of the fictitious crack model is demonstrated by comparison of the experimental load-deflection curve for a small notch bend mortar specimen with a theoretical curve calculated from data obtained from larger beams. It is suggested that the RILEM test method for the determination of the fracture energy should be used also to establish a bilinear stress-displacement relationship for the strain-softening of the fracture process zone. © 1992 RILEM.