Experimental study of precambered steel plate strengthened reinforced concrete columns

Abstract

Steel jacketing has been extensively used for strengthening reinforced concrete (RC) columns. A large number of experiments have been conducted to evaluate the ductility and shear performance of steel jacketed columns. However, in practice, the RC columns to be strengthened are usually subjected to pre-compressed axial loads. The stress lagging effect between the original column and the new jacket due to the preloading has not been addressed. In this paper, a simple and innovative post-compression approach is proposed to strengthen preloaded RC columns, in which slightly precambered steel plates are bolted to the RC column. This paper presents the results obtained from the tests on five RC columns, of which four are strengthened by precambered steel plates and the rest without strengthening acts as a control specimen. All the composite columns are subjected to pre-compressed loading before strengthening. The experimental results show that this approach is effective in improving the axial load capacity of plate strengthened RC columns. Furthermore, the improvement to deformation of the precambered plate strengthened columns is reported.