Fundamental study on experiments for torque shear test to evaluate bonding strength of steel-concrete joint

For better design and construction of steel-concrete hybrid structures, it is important to evaluate the strength and behavior of their joints: e.g. headed studs. However, the contribution of the adhesion and friction along the steel-concrete interface are ignored in such mechanical joints. We here try to propose a new torque shear test system by which the shear strength of the friction and adhesion can be evaluated appropriately. The test specimen has a cylindrical interface in mortar block, and it becomes the interface subjected to the torque shear loading. The results showed that cracks initiated on the side of the specimen were due to the boundary conditions rather than strength of steel-mortar interface and they should be prevented, and the maximum shear stress and residual shear stress were insensitive to the additional reaction force on the steel cylinder of the torque shear test system.