Seismic performance of semi-precast composite columns with bolted end-plate connections to footing

To improve manufacturability in factories, constructability on-site, and structural performance at ultimate states, a new method for semi-precast composite columns was developed using corner steel angles and internal moulds. To verify the proposed method, full-scale mockup testing and quasi-static testing were performed for five column specimens with bolted end-plate connections to the footing. Test parameters included joint details and shear connectors. The test results showed that, although a monolithic column specimen exhibited better performance, overall, the semi-precast composite columns with the connections also showed satisfactory behavior in terms of lateral strength, stiffness, displacement capacity, and energy dissipation. The test results were compared with the predictions by numerical analysis and current design codes assuming a fully rigid joint and full composite action. The numerical analysis results and calculated design strength agreed well with the test results, which implies that current design methods are applicable to the design of the proposed column method.