Influence of Further Corrosion on Structural Behavior of Corroded Reinforced-Concrete Beam Strengthened with Steel Plate Using Different Strengthening Schemes

Abstract

This paper presents the results of an experimental study investigating the mechanical behavior of corroded beams strengthened by three different strengthening schemes, and the influence of further corrosion on the structural performance of strengthened corroded beams. Eight rectangular reinforced-concrete (RC) beams were tested through a three-point bending system. The experimental results showed that the failure modes of the strengthened corroded beams were diagonal tensile failure, flexural failure, and support crush failure, respectively. The increases in ultimate load capacity and rigidity of the corroded beams strengthened with combined strengthening were up to 39.44% and 127.57%, respectively, compared with those of the corroded beams. The ductility of the tested beams strengthened with a single U-shaped steel strip was 16.97% greater than that of the corroded beams, while the ductility of the corroded beams strengthened with flexure strengthening and combined strengthening was, respectively, 4.6% and 28.8% lower than that of the corroded beams due to brittle failure. Compared with the strengthened corroded beams, the ductility and ultimate load capacity of all strengthened beams subjected to further corrosion (5% average corrosion loss of the cross section of the tensile steel bar) increased from 53.14% to 73.39% and from 37.37% to 53.13%, respectively. It was found that further corrosion had a small influence on the rigidity of tested beams strengthened by flexure strengthening and combined strengthening as opposed to the beams strengthened by shear strengthening.