RC Columns Strengthened with Steel Angles and Battens: Experimental Results and Design Procedure

In this paper, an analytical model for the design of axially loaded strengthened RC columns with steel angles and battens is presented. Cases of directly loaded and not directly loaded steel angles are considered. The model considers the contribution in confinement pressures caused by transverse battens and steel angles and the contribution in terms of the load-carrying capacity of steel angles subjected to axial force and the bending moment. An experimental investigation on the compressive behavior of eight short, confined, RC columns externally strengthened with steel angles and steel battens with various pitches was carried out, and has been utilized as support for the analytical model. The analytical results generated are compared with the experimental data available in the literature and with those obtained by using existing analytical models. The comparison shows the acceptable prediction of the experimental results in both cases of directly loaded and not directly loaded steel angles. Finally, some design rules given by recent codes for the design of this strengthening technique are discussed using the proposed model.