Experimental investigation of the time-dependent behavior of quartz sandstone and quartzite under the combined effects of chemical erosion and freeze–thaw cycles

Abstract

Rocks in geotechnical engineering in cold regions are susceptible to chemical corrosion and freeze-thaw cycles of groundwater or acid rain. In this study, the time-dependent behavior of quartz sandstone in HCl solution and quartzite immersed in four different chemical solutions (acidic HCl solution, neutral NaCl solution, alkaline NaOH solution and distilled water) and freeze-thaw cycles were studied. The results show that the long-term strength, elastic modulus and viscosity coefficient of quartz sandstone decrease with the increase of freeze-thaw cycles after immersion in HCl solution, while the instantaneous strain and creep strain increase. In addition, the elastic modulus of quartzite is the most damaged after HCl solution corrosion, followed by NaOH, and NaCl and pure water in turn. Finally, the damage of micro-structures of quartz sandstone and quartzite under the coupling of chemical corrosion and freeze-thaw cycles was analyzed by means of scanning electron microscope (SEM). The image was basically consistent with the corrosion-freeze-thaw phenomenon of the rock sample. The research results can provide reference for the construction and development of rock structures in cold regions.