Three dimensional Experimental Study on Mechanical Behavior of Cemented Granules by Different Bond Agents

Abstract:

The distinct element method had been widely used to study the macro & micro mechanical behaviors of granular materials, and hence it became more and more important to introduce a reasonable and accurate contact model, which can be applied in a 3D simulation of structured soils. The micro model test method was adopted to analyze the interparticle bond contact responses. Two types of bonded granules glued together with epoxy adhesive or aluminous cement were firstly prepared by a novel selfdesigned apparatus, and then a series of tests, including tension, compression, shear, bending and torsion tests, were subsequently carried out using a rock rheological testing machine and some specific auxiliary loading devices. Test results show that the intergranular bond mechanics and strength envelopes are closely related to the cement agents. The forcedisplacement and the moment/torquerotational angle relationships are approximately linearly in the prefailure stage, while they are different in the postfailure stage for different cement agents, as plastic for epoxy and brittle for cement. Normal force performs a significant influence on the mechanical behaviors of interhemisphere bond; both the critical normal force and stress ratio vary with the cement agent. Under different load space, the shapes of the strength envelopes, where the peak shear strength (shear strength, moment and torque versus normal force) appear nearparabolic.