Abstract
Fracture processes of argillaceous schist and granite subjected to freeze-thaw cycles were investigated based on their deformation behaviors. It was found that argillaceous schist showed apparent anisotropy in deformation. Significant extensile strain was observed in the direction perpendicular to the cleavage plane around -3°C in freezing process on the water-saturated specimen, followed by extensile plastic strain at the end of the cycle. No apparent extension and anisotropy were found on the water-saturated specimen of granite, but decrease in contraction rate was seen at -3°C in freezing process with AE activity. The extensile plastic strain of both rocks gradually increased with the number of freeze-thaw cycles, but magnitude of the plastic strain on argillaceous schist was much greater than that of granite. These results indicate that there might be common mechanism in fracture process between both rocks, but significant differences in deterioration rate. Deterioration of argillaceous schist is much faster because fracture mainly develops by extension of well-developed cleavage in the rock. It was concluded that weak plane such as cleavage strongly affected deterioration of rocks by freeze-thaw cycle.
