Mechanical properties and energy features of high-water material under cyclic loading and unloading

Abstract

The mechanical properties and energy features of high-water material under cyclic loading and unloading were studied. Results show that: cyclic loading and unloading has a weakening effect on the peak strength and has a strengthening effect on the residual strength of high-water material. During cyclic loading and unloading process, the stress-strain hysteresis effect is obvious. In the cyclic loading and unloading test with gradual increase of stress level, elastic modulus increases first and then decreases, total work, elastic energy, dissipation energy and energy dissipation rate of specimens increase as cycle number increases. In the cyclic loading and unloading test with constant stress level, elastic modulus decreases gradually, total work, elastic energy and dissipated energy of specimens remain stable overall as cycle number increases. Comparing with cyclic loading and unloading test with constant stress level, mass loss rate and energy dissipation rate of the same water to cement ratios specimen are greater in the cyclic loading and unloading test with gradual increase of stress level, it is easier to promote the accumulation and development of internal damage of high-water material. [Received: October 27, 2017; Accepted: July 31, 2018]