Fracture and Slip of Interfaces in Cementitious Composites. I: Characteristics

Abstract

A new and relatively simple constitutive theory that describes fracture and slip of an interface in cementitious composites such as concrete is presented. The constitutive model is developed and formulated in analogy to the theory of incremental plasticity. Adhesion, debonding and mobilized friction mechanisms are considered in the characterization of the interface behavior. The debonding mechanism in the presence of a combination of normal and shear stress, i.e., the degradation of tensile and shear strengths, is monitored via a work‐softening rule that entails tensile crack opening as well as tangential slip. As a result, a fracture energy release‐based plasticity model is obtained. The material parameters are physically transparent and are conveniently calibrated from characteristic response functions that can be observed experimentally in pure tension and in pure shear. Analytical predictions are compared with experimental results for the case when constant normal traction is applied while the slip displacement is monitored.