Investigation of the microstructural characteristics of heated sandstone by micro-computed tomography technique

Abstract Heritage buildings always pose challenges due to experiencing high temperatures and pressure over time. Sandstone is one of the common sedimentary rock types used for these buildings. Therefore, it very important understand microstructural variations rocks associated with constructions along mechanical variations. In this study, alteration selected sandstones investigated after heated from room temperature 800 °C. Micro X-ray computed tomography (µXCT), diffraction (XRD), scanning electron microscopy (SEM), thermogravimetry (TG) derivative (DTG) techniques were identify physical, chemical, mineralogical changes sandstone different heat treatments. The specimens was also studied using point load index (PLI). main in microstructure observed when sandstone’s greater than 400 total porosity measured by µXCT increased more 70% at °C compared its temperature. When increases, open increases while closed decreases. Noticeable mineralogy identified exceeding °C, which can be attributed phase transition quartz, decomposition feldspar dehydroxylation kaolinite. TG DTG analyses good agreement concerning mineralogy. Microstructural variation reasons discrepancy threshold values between sandstones.