Quantification of thermally-induced microcracks in granite using X-ray CT imaging and analysis

Abstract

The influence of heating followed by cooling on the alteration of the microstructural properties of Harcourt granite was comprehensively investigated utilising X-ray computed tomography (CT) imaging and three-dimensional (3-D) image reconstruction and analysis. Two cooling treatments, rapid and slow cooling, were adopted with preheating temperatures ranging from 25 to 1000 °C. The pore spaces of the thermally-treated specimens were analysed to obtain their porosity and pore connectivity and to generate pore network models (PNMs). According to the results, no significant microcracking occurs up to the preheating temperature of 200 °C and regardless of the cooling treatment, microcracks start ..