Evolution of absorption energy per unit thickness of damaged sandstone

Abstract

This paper experimentally studies the evolution of absorption energy characteristics per unit thickness of Jhiri sandstone at variable temperatures (from 25 to 900 °C), each specimen being heated at the heating rate of 5 °C min−1. Each specimen was kept at its designated temperature which, once reached, is kept constant for 12 h and cools down at 0.364 °C min−1 rate till achieving at room temperature. Laboratory tests including DTA/TGA, thin section, SEM/EDAX, P-wave velocity and Brazilian tensile strength were conducted in this study. Geochemical and thermal analyses were performed to investigate the changes in the physical and chemical properties of the sandstone after high thermal treatment. However, when the temperature exceeds up to 300 °C, it is found that intragranular cracking is highly temperature dependent. Damage thresholds temperature has been found to be 300 °C. The absorption energy caused by high temperature can be better understood by the mass loss rate than P-wave velocity loss rate and tensile strength loss rate. The result obtained in this paper will be useful for predicting the evolution of absorption energy characteristics of sandstone when exposed to the high-temperature environment. © 2018, Akadémiai Kiadó, Budapest, Hungary.