Abstract

At microscopic level, natural flaws act as stress concentrators in rock, favoring brittle fracture. Acoustic emission (AE) monitoring was applied for the qualitative and quantitative assessment of the fracturing process in two types of rocks subjected to diametral compression tests. The process was based on AE parameters, petrographic analysis, signal processing in the time-frequency domain, and three-dimensional localization. It was observed that the fracturing pattern in both rock types depends on the rock fabric. However, regardless of the rock type, crack propagation is characterized by wide-band emissions. The modes of cracking showed dependency not on the rock fabric but on the softening process.