Experimental Study on the Effect of Water Content on the Mechanical Properties of Rock-Like Materials Under Freeze-Thaw Action

Cold region engineering has always been the most challenging problem in civil engineering. To explore the effect of water content on the mechanical characteristics of rock materials under freeze-thaw action, both static and dynamic uniaxial compressive tests were implemented for rock-like specimen with 0, 1, 2, and 3% water contents after cyclic freeze-thaw treatment, then numerical simulation software LS-DYNA was adopted to explore the damage process of rock-like specimens. The dynamic uniaxial compressive tests were carried out at 0.4 MPa impact pressure. Test results indicate that static and dynamic uniaxial compressive strength, absorbed energy, and energy absorption rate all diminish with the freeze-thaw cycles, but the damage of rock-like specimen under impact load gradually increase. Moreover, the mechanical properties of water-containing rock-like specimen suffering cyclic freeze-thaw treatment are much smaller than those of dry state rock-like specimen. SEM images reveals that the micro-structure of rock-like specimen after freeze-thaw action becomes increasingly loose as the water content increases. Due to the periodic frost heaving and heat melting during cyclic freeze-thaw treatment, the deterioration effect of freeze-thaw action is intensified by the water in the specimen. The larger the water content, the worse the deterioration effect.