Experimental Study On Shear Performance of Steel–Concrete Composite Bolted Connectors in Precast Concrete Shear Walls

To explore the shear performance of steel-concrete composite bolted (SCCB) connectors used in precast reinforced concrete (RC) shear walls, 16 specimens were designed and tested under monotonic loading, taking the bolt diameter, bolt pretension force, bolt hole diameter, concrete compressive strength, sandwich concrete thickness, thickness of inner plate and cap plate into consideration. The failure modes, load-slip curves, bolt force, shear bearing capacity as well as the shear stiffness of the tested specimens were obtained accordingly. Test results demonstrated that two failure modes involved bolt shear failure and bearing failure were observed in all specimens, the failure mode that was experienced mainly depended on bolt diameter, inner plate thickness and cap plate thickness. The peak load for specimen with bolt diameters of 16 mm showed an improvement of over 52% than that with bolt diameters of 24 mm, but the variation of shear stiffness was less than 8.1%. About 16.6% and 23.5% increase in peak load and shear stiffness for specimen with C50 concrete was observed than specimen with C30 concrete. Compared to specimen with cap plate thickness of 6 mm, the peak load and shear stiffness of specimen with cap plate thickness of 14 mm are increased by 9.8% and 56.2%, respectively. In addition, the sandwich concrete thickness, bolt pretension force, bolt hole diameter and inner plate thickness had only a minor influence on the peak load and shear stiffness of the SCCB connectors.