Experimental Study on Damage Deterioration and Tensile Characteristics of Rock under Freeze-thaw Environment

The basic mechanical problem facing of environmental geotechnical engineering in cold regions is the physical and mechanical properties of rocks under freeze-thaw conditions. The freeze-thaw cycling experiment was conducted first for two types of rock which are red sandstone and shale, then the splitting tensile experiment on different freeze-thaw cycles. The damage deterioration and breaking behavior under freeze-thaw conditions was investigated, and the influence of lithology and freeze-thaw cycle on anti-tensile characteristics of rock was studied. It is shown that three freeze-thaw damage deterioration modes of two kinds of rock are spalling mode, fracture mode and crack mode. The freeze-thaw cycle leads to irreversible deterioration on physical and mechanical properties for rock, but the damage of red sandstone is more serious than that of shale by the number of freeze-thaw cycles. The regularity of freeze-thaw effects of compression and tensile characteristics for two rocks are identical, but the tensile characteristic is more sensitive to freeze-thaw cycle.