Generation and visualization of microfractures in Carrara marble for estimating fracture toughness, fracture shear and fracture normal stiffness

A procedure to generate and visualize microfractures in Carrara marble by triaxially loading of cylindrical specimen to desired stress levels is presented. The visualization of the microstructures was achieved by cutting continuously perpendicular sections off the specimen and staining the surfaces with drawing ink. The surfaces were digitized by a scanner and the microfractures were recorded by length, orientation, width and the coordinates of crack ends, respectively. From back-analysis applying the BEMF code, fracture toughness, shear and normal fracture stiffness were calculated.