Investigations on fracture properties and analytical solutions of fracture parameters at rock-concrete interface

To investigate fracture properties and find analytical solutions of parameters at rock-concrete interface, three-point bending tests were performed on the composite specimens with different degrees interface roughness. Numerical simulations conducted to analyse crack propagation process zone evolution interface. For convenient applications in practice, a series derived or curve-fitted calculate The results indicate that roughness degree has significant effects With increase degree, energy, critical length double-K exhibit obvious increasing tendencies. Meanwhile, ratio unstable toughness concrete is much less than initial toughness, indicating weaker cohesive effect compared concrete. In addition, fully formed FPZ corresponding ligament decrease. characteristic proved decrease larger brittle behaviour degree. Finally, expressions under loading, including mode-I stress intensity factor,