Behavior of Reinforced Concrete Columns Confined by New Steel-Jacketing Method

Jacketing can be an effective way to improve the performance of the lap-spliced region of reinforced concrete (RC) columns. This paper introduces a new steel-jacketing method for RC columns that uses external pressure to attach the steel jackets to the column surface. The advantage of this method is that it does not require the application of grout between the steel jackets and the concrete surface to attach them together. Experimental tests of twelve concrete cylinders and four RC columns are performed to assess the effectiveness of the proposed method. Both single-layered and double-layered jackets are tested. The newly jacketed cylinders show good results in terms of increasing the compressive strength and ductility compared to plain cylinders. The double-layered jackets are estimated to show equal performance to that of a single steel jacket with the same thickness. The proposed steel-jacketing method increased the ductility of lap-spliced RC columns. The double-layered jacket appeared to perform better in terms of increasing ductility and energy dissipation capacity than the single-layered jacket.