Effect of position of non-contact lap splices on in-plane force transmission performance of horizontal joints in precast concrete double-face superposed shear wall structures

In this study, the three-point bending beam test was used to investigate the in-plane force transmission performance of precast double-face superposed shear walls (DPCW) with horizontal joints. The effects of the net distance between the dowel steel bars and the inner side of the prefabricated wall panel (s = 0, 20, and 40 mm) and span-to-depth ratio (lambda= 1.0, 1.6 and 2.2) on the failure modes, load-deflection curve, load-strain response, bearing capacity deformation performance, stiffness degradation, and relative displacement at the joints were evaluated. The results indicate that the post-cast and precast concrete interfaces influence the in-plane force transmission performance of the non-contact lap splices. The force transmission performance with a net distance of 20 mm is the best, compared to the net distances of 0 and 40 mm. Therefore, it is recommended to control the net distance between 15 and 30 mm in the actual engineering design and construction of the DPCW system. Considering the effect of lambda, the results show that when the lambda(1) is relatively small, the shear force at the joints is mainly borne by the dowel steel bars, and its in -plane force transmission performance is close to that of the specimens without horizontal joints. However, with an increase in lambda(1), the bending moment dominates at the joints. At this time, a non-contact lap splice can be simulated as a plane truss on the tensile side of the shear wall joint. The concrete between the dowel steel bar and distributed steel bar acts as an inclined strut to achieve non-contact force transmission of the lap splice.

Automated summary

This study investigated the in-plane force transmission performance of precast double-face superposed shear walls with horizontal joints using the three-point bending beam test. The effects of the net distance between dowel steel bars and the inner side of the prefabricated wall panel, as well as the span-to-depth ratio, were evaluated. The results showed that the force transmission performance was influenced by the concrete interfaces and the optimal net distance was found to be 20 mm. The study provides recommendations for the engineering design and construction of the DPCW system.