EFFECT OF PARTICLE SIZE RATIO AND MIX RATIO ON MECHANICAL BEHAVIOR OF RUBBER-SAND MIXTURES

Rubber-Sand Mixture(RSM)has recently been demonstrated to be a new type of low cost isolation material with wide application. The mechanics and deformation characteristics of RSM can vary with mix ratio and particle size ratio of the two base materials. In order to promote the engineering application of RSM, a series of biaxial compression tests are conducted numerically on three kinds of particle size ratio and six kinds of mix ratio based on DEM simulation. Influence mechanisms of particle size ratio on macroscopic and mesoscopic characteristics are analyzed. Results indicate that:(1)The stress-strain curves of RSM show a linear growth relationship under small strain. With the increase of rubber content, the deviator stress and its degree decrease with increase of particle size ratio. (2)With the increase of rubber content, the modulus of RSM decreases, and the hardening characteristics of specimen is enhanced. The larger the particle size ratio, the more evident the degree of hardening. (3)With the increase of rubber content, volumetric expansion of RSM is decreased, and the contraction characteristics of specimen is enhanced. The larger the particle size ratio, the more evident the degree of contraction. (4)The stress-strain behavior of RSM can be simulated well with the extended Duncan-Chang hyperbola model, and the influence of particle size ratio and rubber particle content on model parameters is obvious. (5)The mesoscopic mechanism of the effect of particle size ratio on RSM can be described by these factors including particle contact characteristics, particle coordination number, force chain distribution, and energy consumption development.