Variable Angle Shear Test and Finite Element Simulation of Polyurethane – Bentonite Composite Structure

Polyurethane grouting is more and more widely used in projects. In this paper, the variable angle shear test (VAST) was carried out on polyurethane – bentonite (PU-B) composite specimens using a set of angle adjustable shear test devices. The failure process of specimens was studied by digital image correlation (DIC) technology. The finite element model was established to simulate the shear failure process of PU-B specimens. The results show that, within the range of angles set in the test, the greater the shear angle, the greater the shear strength of the specimen. The normal component can improve the shear strength of the PU-B specimen to a certain extent. The relationship between the normal stress and the tangential stress in cases of specimen failure conforms to the linear law, from which the cohesion and internal friction angle of the PU-B composite specimen can be obtained. The finite element simulation results are basically consistent with the VAST results. The conclusions may play a role in the study of the shear properties of the interface between polyurethane and bentonite to some extent.