Hysteretic behavior of precast concrete shear walls with steel sleeve-corrugated metallic duct hybrid connections

In this paper, a hybrid connection that incorporates grouted steel sleeve splices (GSS) and grouted corrugated metallic ducts (GCMD) for precast concrete shear walls (PCSWs) is proposed. This hybrid connection uses GSS in the boundary elements and GCMD for vertical reinforcements in the middle part of the walls, which aims to balance the cost, efficiency of construction and the mechanical performance. In order to investigate the behavior of this hybrid connection, cyclic test with a high axial compression ratio of 0.24 on seven full scale shear wall specimens was conducted, with the consideration of different splicing methods (hybrid, GCMD and GSS) and rows of connections (one-row and two-row). Test results indicated that all PCSWs failed by flexural-shear and their hysteretic loops were relatively plumper than the CIP reference wall. The load carrying capacity of all specimens was very close and their differences were less than 10%. The displacement ductility of the PCSWs with hybrid connections was 2.45 and 3.08, which was lower than the specimens with GSS and GCMD connections, but was still significantly higher than that of the CIP specimen (1.82). The ductility of the PCSW with one-row hybrid connections was found slightly better than that of the specimens with two-row connections. It was also revealed that specimens with hybrid connections had very similar stiffness degradation characteristics to those of the CIP specimen and showed dramatically higher energy dissipation capacity. Moreover, based on the test results, a degraded quadrilinear restoring force model was proposed.