Experimental study on the effect of water content on the mechanical properties of rock-like materials under freeze-thaw action

In order to study the effect of water content on the mechanical properties of rock-like materials under freeze-thaw action. Static uniaxial compression test and dynamic SHPB test were carried out on dry rock-like and rock-like with water content of 1%, 2% and 3% under different freeze-thaw cycles. The static and dynamic mechanical properties were analyzed, and the damage and deterioration mechanism of rocks with different water contents was analyzed by SEM test. The results show that the static compressive strength of four groups of rock samples with different water content decreases with the increase of freeze-thaw cycles. With the increase of water content, the static compressive strength also decreases gradually. Under the condition of the same impact pressure, the dynamic stress-strain curves of samples with different water contents all experienced elastic stage, nonlinear deformation stage and failure stage. The dynamic energy absorption rate decreases with the increase of freeze-thaw cycles, and the degree of fragmentation of the specimens is also increasing. With the increase of water content, the energy absorption rate showed a decreasing trend, and the fragments of the specimens gradually changed from block to granular or even powder. It can be seen from the SEM image that the internal structure of the dry rock is closely arranged, and the number of cracks and pores is relatively small, which has excellent resistance to impact power. With the increase of water content, the internal structure becomes more and more loose.