Seismic performance of a ductile rod exterior connection system for precast concrete industrial buildings

The seismic performance of a ductile rod system for exterior precast concrete beam-to-column connections was experimentally evaluated. Five full-scale precast concrete beam-to-column subassemblies connected with ductile rods were fabricated, considering various aspects (ductile rod size, prestressing, and flexural/shear capacities). Lateral cyclic loading tests were conducted for the precast concrete connections along with two monolithic reinforced concrete connections. Despite their relatively lower lateral stiffness, most precast concrete connections showed sufficient moment capacities with peak moments at approximately 3% to 4% interstory drifts. The prestressing tendons were effective at enhancing moment and shear strengths of the precast concrete connections, as well as in reducing slip of the ductile rods. The precast concrete specimens generally showed satisfactory seismic performance, fulfilling acceptance criteria specified by the American Concrete Institute. The test results demonstrated that careful considerations are required in the design of ductile rods and high-strength threaded bars to induce stable flexural responses of the precast concrete connections.