Preliminary results on corrosion products characterization in reinforced concrete subject to chloride-induced corrosion over more than 20 years

For reinforced concrete structures subject to chloride-induced corrosion, the assessment of service life at the design stage is often limited to the corrosion initiation phase, whereas in practice many structures are in the corrosion propagation phase. In these cases, for a proper assessment of the residual service life, it is necessary to better understand the processes leading to the detachment of the concrete cover, usually associated with the end of the service life, by studying the development of corrosion at the microscopic level over time. This note reports some preliminary results obtained during a research program aimed at characterising corrosion in reinforced concrete specimens cast in 1998, subjected to accelerated penetration of chlorides, and subjected to natural corrosion propagation over more than 20 years. Corrosion products and the steel-concrete interface were characterised through a combination of optical microscopy, SEM, Raman spectroscopy and computed tomography.