Tension-Softening Properties for Concrete-Concrete Interfaces

The tension-softening parameters for different concrete-concrete interfaces are determined using the bimaterial cracked hinge model. Beams of different sizes having a jointed interface between two different strengths of concrete are tested under three-point bending (TPB). The load versus crack mouth opening displacement (CMOD) results are used to obtain the stress-crack opening relation through an inverse analysis. In addition, the fracture energy, tensile strength, and modulus of elasticity are also computed from the inverse analysis. The fracture properties are used in the nonlinear fracture mechanics analysis of a concrete patch-repaired beam to determine its load-carrying capacity when repaired with concrete of different strengths.