Long-term corrosion behavior of carbon steel in carbonated concrete made with different binders|Corrosione a lungo termine di armature di acciaio in calcestruzzi carbonatati con diverse composizioni

To properly predict the service life of a reinforced concrete structure subjected to carbonation-induced corrosion, a correct estimation of the propagation period is needed. The propagation period is related to the rate at which the corrosive attack propagates, and mainly depends on the exposure conditions and the concrete quality. This paper reports the preliminary results of a research aimed at investigating the corrosion conditions of steel in carbonated concrete, made with different compositions and exposed for more than 15 years to an unsheltered outdoor environment. Preliminary results showed the fundamental role of concrete composition in determining the corrosion behavior of steel bars, leading to significant different damage conditions, from the absence of cracking to the complete concrete cover detachment. Moreover, the correlations between the corrosion rate and concrete resistivity as well as corrosion potential were investigated.