An Experimental Investigation on the Mechanical Behavior Between Cemented Granules

An experimental investigation of the mechanical behavior of cemented granules is presented in order to verify and further clarify the bond contact model used in numerical simulations of cemented sands. The cemented granules were idealized by a pair of aluminum rods glued together by means of calcium aluminate cement. A series of cemented rods was prepared using a specially designed sample preparation device. Then, the mechanical relationships between the cemented rods (i.e., force-displacement relationships and failure conditions) were examined in both simple loading and complex loading tests using newly developed auxiliary loading devices. The results show that the tensile force increases linearly up to its peak strength and then drops suddenly to zero, whereas the compressive force increases bilinearly up to its peak strength and then decreases to the residual strength gradually. Similarly, the shear force increases almost linearly up to its peak strength and then drops to the residual strength rapidly, whereas the torque increases up to its peak strength and then decreases to the residual strength gradually. In addition, both the peak shear strength and the peak torsional strength increase at first and then decrease with increasing normal force. The strength envelope of the cemented rods is observed to be an olive-shaped shell in the shear force-normal force-torque space.