Lateral strength model for preloaded rectangular RC columns strengthened with precambered steel plates

Abstract

Rectangular short reinforced concrete (RC) columns with non-ductile details subjected to high axial loads exist in many buildings, especially for those built before 1970s without consideration of the seismic design. When subjected to a rare earthquake load attack, those columns are prone to brittle axial failure with limited deformability, which could lead to partial or total collapse of the building. To address this issue, this study adopted precambered steel plate to reduce the axial load level and hence increase the deformability of the strengthened column. A theoretical model is derived for estimating the ultimate lateral load capacity of the strengthened column. In this model, the effect of pre-existing gravity loads in the RC column is taken into account. Furthermore, a coefficient is introduced to account for the partial interaction between the concrete column and steel plates. Finally, the predicted results are compared with the available experimental results to validate the theoretical model.