Relationship between Fracture Surface Roughness and Fracture Behavior of Cement Paste and Mortar

Abstract

Fracture surfaces of cement and mortar specimens were characterized using a confocal microscope to create three‐dimensional computer‐based topographic maps. The texture of the fracture surfaces was quantified using image analysis techniques to compute a roughness parameter and fractal dimension. Total porosity, pore‐size distribution, compressive strength, and fracture properties of the specimens were determined and compared with the roughness parameter. Fracture properties were determined by notched‐beam tests and the results were analyzed both by using conventional linear elastic fracture mechanics as well as a compliance‐based approach that incorporated R ‐curve type of behavior. A positive correlation between fracture surface roughness and fracture toughness was demonstrated.