Degradation of physical and mechanical properties of sandstone subjected to freeze-thaw cycles and chemical erosion

Abstract

Rocks are often exposed to chemical erosion and extreme temperature changes in cold regions. In this study, the deterioration of sandstone is investigated under rapid freeze-thaw (F-T) cycles. To do so, physical and mechanical properties of sandstone specimens immersed in different chemical solutions were studied after 10, 20 and 30 freeze-thaw cycles. It was found that after applying freeze-thaw cycle specimens' mass, tensile strength and point load strength decrease at different extent while porosity increases. Coupled effects of chemical erosion and freeze-thaw cycles were observed to have a destructive damage on physical and mechanical properties. In this regard, the samples experienced deterioration at different extend when immersed in different chemical solutions. The maximum deterioration was observed for samples being immersed in NaOH solution, followed by that of NaCl solution, H₂SO₄ solution and pure water. Finally, a decay function model is used to further investigate the variations of splitting tensile strength and point load index with freeze-thaw cycles and predict deterioration of rock integrity.