Theoretical and experimental study of plate-strengthened concrete columns under eccentric compression loading

Steel jacketing has been widely used for strengthening RC columns in the last four decades. In practice, the RC columns to be strengthened are usually subjected to eccentric precompressed axial loads. Until now, there have been only limited studies conducted that address the stress-lagging effects between the original column and the new jacket due to the preexisting load. In this paper, the precambered steel plate-strengthening approach, which can alleviate the stress-lagging effects, was adopted to improve the axial strength and moment capacity of the preloaded RC columns subjected to eccentric compression loading. An experimental study that involved eight specimens with different eccentricities, plate thicknesses, and initial precamber displacements was conducted to examine the ductility and moment-curvature response of strengthened columns and to validate the effectiveness of this approach. A theoretical model was developed to predict the axial load capacity of the plate-strengthened columns. A comparison of the theoretical and experimental results showed that the theoretical model accurately predicted the axial load-carrying capacities of the plate-strengthened columns under eccentric compression loading.