The precast shear wall behavior in the serviceability and ultimate limit states depends on the shear and shear-flexural behavior of the joints between the precast components or between the precast component and footing. This study presents a series of tests on the shear strength of joints, which were applied to the interface of precast shear walls. The tested parameters included the joint types, the numbers of shear keys, the existence of high strength steel bars inserted at the joints, and the levels of confining stress. The shear capacity, stiffness, and shear transfer mechanisms of these joints were investigated. It could be concluded that the epoxied and high strength reinforcing joints had consistently higher shear strength than that of dry and plain joints. For the specimens with an inclined angle at the end of the keys of less than 60 degrees, the width of the dry joint opening may be excessively large, resulting in large shear slip and the key not shearing-off under confining stress of less than 1.0 MPa. The tested results were compared with AASHTO and other design criteria. Several formulas regarding the joint shear capacities were also proposed according to the specifications and the tested results.

The behavior of precast concrete structures at the limit states of ultimate bearing capacity depends on the shear and shear-flexural behavior of the joints between precast components, such as shear wall and beam-column joints, or between the precast component and footing. This study presented a series of tests on the shear-flexural behavior of precast concrete joints applied in precast structures with high strength reinforcement. The tested parameters of the specimens included the joint type, shear-span ratio, longitudinal reinforcement ratio, reinforcement type, and prestress. The tested results indicated that, for the precast joint specimens controlled by shear failure, the prestress by the high strength reinforcement can significantly improve the crack behavior, shear bearing capacity and stiffness of the precast structure. So it can emulate the monolithic cast-in-place specimen. For the precast joint specimens dominated by bending failure, the local deformation was mainly concentrated on the precast joint region, which affected the distribution of the plastic hinge region. To reduce the adverse effects by the precast joints, a grouting material with better performance should be used to improve the bond behavior of the reinforcement.

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A new type of prefabricated reinforced concrete-Y-shaped eccentrically steel brace structure (PRC-Y-ESBS) is developed by combining the mechanical property of prefabricated reinforced concrete frame and Y-shaped eccentrically steel brace, so the seismic performance and seismic resilience capacity of prefabricated reinforced concrete frame can be effectively improved. In the PRC-Y-ESBS, the precast concrete beam-to-shear link composite connection should have enough bearing capacity and resilience capacity under the shear force and bending moment, so the damage can be restricted in shear links. In this paper, an innovative precast concrete beam-to-shear link composite connection (PCB-SLCC) with bending moment and shear force separate method is proposed. Four different types of shear connectors are analyzed in detail by using the verified numerical method, and the shear capacity and failure mode of shear connectors can be obtained. Then, the innovative PCB-SLCCs with the reasonable shear connector considering different influencing parameters are also studied in detail. The results indicate that the shear connectors and high-strength bolts are still in elastic state at ultimate load, and little damage has occurred in the concrete between the embedded plate and precast concrete frame, while the PCB-SLCC has enough bearing capacity at the ultimate stage. In addition, this study also clearly identifies that high-strength bolts can only bear the bending moment, and the shear force is only carried by shear connectors, so the bending moment and shear force of the innovative PCB-SLCC with high bearing capacity, ease of installation, and seismic resilience capacity can be apparently separated.