Mechanical and fracture behaviors of compacted gold mine tailings by semi-circular bending tests and digital image correlation

摘要

The storage and handling of mine tailings (MTs) pose significant economic and environmental problems and finding suitable recycling or re-use alternatives for MTs is an on-going process. One of those alternatives is creating MTs-based adobes or compacted MTs, which then can be used in construction materials and ground stabilization applications Therefore, the fully understanding of the mechanical and fracture behaviors for the compacted MTs are significant for the applications. However, no study on such behaviors of the compacted MTs was documented in the literature. In this study, the investigations of the mechanical and fracture behaviors of the compacted MTs were carried out experimentally by using semi-circular bending tests (SCB) and digital image correlation (DIC). The SCB tests were conducted by using three-point bending instruments. Mode I fracture behaviors were therefore obtained by manually setting different notch depths with various loading span distances. The influences of notch depths and span distances on the Mode I fracture toughness, KI, were obtained by testing the notched SCB specimens. Additionally, the influences of notch depths and span distances on the fracture process zone (FPZ) and fracture energy were evaluated. Results showed that the measured Mode I fracture toughness was not evidently influenced by the notch depths and span distances. The fracture energy decreased with the increase of notch depth and span distance. Finally, the maximum major principal strains were found to increase with the increase of notch depths.