A novel seismic connector for precast concrete shear walls

A critical aspect of the seismic performance of precast concrete walls is the deformation capacity of their connections, which can be limited by premature bar fracture, reinforcement buckling, or cyclic instability. This paper introduces and experimentally validates a new ultra‐ductile connector (UltraDC) that provides reliable force transfer and inherent ductility. The UltraDC is developed to enhance the displacement capacity and reliability of precast concrete wall connections while remaining compatible with typical precast detailing and construction sequences. The proposed configuration consists of a cruciform yielding element housed within a hollow outer steel sleeve, which provides lateral anti‐buckling restraint to the yielding segment while also serving as the anchorage mechanism to the surrounding concrete. Prototype UltraDC specimens were evaluated through cyclic tension‐compression connection tests and benchmarked against a conventional grouted dowel precast connection. The experimental program included three configurations: a single UltraDC connector, two UltraDC connectors arranged in series, and a headed‐bar specimen with the cruciform yielding element directly embedded in the concrete. The test results showed that the UltraDCs sustained a stable hysteretic response under large displacement demands and achieved at least 82% greater tensile displacement capacity than the conventional grouted dowel connection. Arranging two UltraDC connectors in series further increased the displacement capacity, although the increase was less than proportional to the increase in total yielding length, likely due to small fabrication variations. Overall, the results demonstrate that the UltraDC concept offers a promising and practically compatible approach to enhancing the ductility of precast concrete wall connections.