Assessment of the seismic behaviour of RC columns

Current codes for earthquake resistant design of RC structures include several provisions that ensure satisfactory behaviour of columns. In order to check the efficiency of relevant code provisions, the behaviour exhibited by tested RC columns is assessed. For this purpose, experimental results on more than 450 RC columns were collected. Their behaviour has been evaluated on the basis of several parameters, namely: the in-section arrangement of hoops, the effective confinement ratio, the spacing of hoops normalized to the longitudinal bar diameter, etc. The main findings of this comparison between experimental results and code provisions are presented in this paper. The present work confirms the beneficial role of multiple hoops, low axial load, high confinement ratios and low values of the spacing of hoops normalized to the diameter of longitudinal bars on limiting the force response degradation due to cycling, as well as on enhancing the ductility of RC columns. In general, code provisions seem to ensure the targeted behaviour.