Visual parameters of chloride-induced corrosion of reinforced concrete structures

Abstract : Corrosion is the major cause of reinforced concrete structures degradation: the pressure generated by oxides formation together with section loss can eventually lead to cracking and the fall in the structure bearing capacity and then jeopardize its service life. The first method for the corrosion state characterisation of concrete structures is to check periodically for visual signs of corrosion on the concrete facing (rust stains and cracks). The goal of this study is to assess the ability of visual inspection to detect and quantify reinforcement corrosion in concrete structures. The data acquired in the framework of the “Poutres de la Rance” benchmark were re-analysed to link the visual signs of corrosion to its real internal consequences (section loss, corroded length… etc.). The results show that, in our case (marine environment), visual inspection does not yield efficient assessment of the real corrosion state and that other non-destructive techniques must be used in order to gain confidence in the diagnosis.