Experimental study and failure criterion analysis on combined compression-shear performance of rubber concrete (RC) with different rubber replacement ratio

Abstract

In order to study the combined compression-shear mechanical properties of rubber concrete (RC), the compression-shear tests of RC under varying axial compression ratios and rubber content were carried out using compression-shear hydraulic servo machine. The shear failure modes and shear load–displacement curves of RC were generated. The characteristics points of load–displacement curves, peak shear strength, residual strength, shear failure displacement, for instance, were also extracted under different loading conditions. The effect of the axial compression ratios and replacement level of rubber particles on the shear mechanical properties of concrete was evaluated. It was reported that shear failure of RC developed slowly while shear failure plane was relatively flat by an increase in axial compression ratio. The friction traces on shear failure plane got more evident when the law of change was not associated to the replacement ratio of rubber particles. Research results also indicated that with successive increase in replacement ratio, the shear strength of concrete gradually decreases while the shear displacement gradually increases. Simultaneously, the increase coefficient of shear load of RC shows a decreasing trend, influenced by the axial compression ratio. The shear strength, residual load and shear displacement were enhanced as the axial compression ratio increased. While the reduction degree of shear load is larger due to the rubber replacement ratio. The cohesion and internal friction angle of concrete decrease by an increase in the rubber replacement ratio while the friction coefficient of the shear failure plane is relatively stable. The failure criterion models of concrete associated with the rubber replacement ratio under combined compression-shear stress are derived from the theory of plane stress space and octahedral stress space. Model results show favorable consistence with experimental data. The manuscript discussed and analyzed the mechanism of concrete under combined compression-shear. The research of this paper is of great significance for scientific research and engineering applications of RC.