EXPERIMENTAL STUDY ON SEISMIC PERFORMANCE OF FULL-SCALE REINFORCED CONCRETE FRAME HOLLOW COLUMNS

A new type of reinforced concrete frame hollow column with spiral hoops at section corners is proposed in this paper. To investigate the seismic performance of this hollow column, 3 full-scale specimens with hollow section and 1 full-scale solid column are designed and tested under pseudo-static load. The failure mode, load-bearing, deformation and energy dissipation capacities of hollow columns and solid column are compared and analyzed. The influence of hollow ratio and axial load on the seismic performance of hollow column are investigated. The results indicate that the spiral hoops provide strong confinement for the concrete. Hence, under an identical axial load, the ductility of hollow column is better than that of the solid column and the load-bearing capacities are approximately identical. Hollow ratio has significant influence on the failure mode and seismic performance of hollow columns. In comparison with the solid column, the hollow column with lower hollow ratio exhibits better ductility and flexural failure mode is also observed on it. In contrast, the hollow column with a higher hollow ratio exhibits worse ductility and flexure-shear failure occurs. The axial load also has some influence on the failure mode and seismic performance of hollow columns. The hollow column with a lower axial load shows better ductility. The research results provide useful reference for further development of the RC hollow column.