Fracture of Rock-Concrete Interfaces: Laboratory Tests and Applications

The fundamental understanding of the fracture behavior at the rock-concrete interface requires evaluation of the fracture energy, which is an interface material property. As in concrete or rock, fracture at the interface is characterized by a steady degradation of its structure. With increasing degradation of the material (opening of the crack), less stress is transferred across the interface until it is completely separated. The interface undergoes tensile softening. Wedge-splitting tests are performed on the limestone-concrete interface to evaluate the Mode I fracture energy. These experiments are followed by linear and nonlinear fracture mechanics based on numerical analysis to obtain the fracture toughness. The fracture parameters so obtained are used in the fracture mechanics-based analysis of a gravity dam for the determination of crack length between the concrete dam and rock foundation