Fracture process zone analysis of concrete using moiré interferometry

The fracture process zone (FPZ) ahead of a crack tip in concrete and mortar beams subjected to threepoint bending was studied using moiré interferometry. A large FPZ can occur in concrete before the external load reaches its maximum value. Comparing the experimental results between concrete and mortar suggests that the aggregate contributes to the formation of the large FPZ in concrete. The formation of this large FPZ makes concrete less brittle than mortar. The effect of the FPZ on the fracture property, such as stress intensity factor, is investigated by combining moiré interferometry measured displacements with the smoothing FEM method. The study shows that a large FPZ significantly affects the value of the stress intensity factor.