Double shearing of rebar steel and cable bolts for effective strata reinforcement
The shearing behaviour of both steel rebar and hollow strand cable bolt across joints and shear planes in concrete blocks is examined experimentally. The steel rebars (bolts) were tested in 20, 40, 50 and 100MPa concrete blocks, subjected to different pretension loads of 0, 5, 10, 20 50 and 80 kN respectively. Shear testing of the cable bolts, was carried out in a 50MP concrete with the cables being tested under two initial axial loading of 50 and 100 kN respectively. It was found that the strength of the concrete has a significant influence on the shear load behaviour and shear deformation of the concrete in the vicinity of the sheared joint planes. Shearing load across the joint planes was less in 20MPa concrete in comparison with higher strength, 40 and 100MPa concrete. Analysis of the failure mode and loads achieved in cable bolt showed that the cable strands bent and the concrete crushed along the shear plane, the shear loading across the concrete and grouted cable then reached the tensile strength of the steel wires.