The corrosion initiation process dynamics of reinforcement steel coated with mortar is studied using a non-linear signal analysis technique named “recurrence plot”. Electrochemical noise current-time series with an open circuit are analyzed to determine the magnitude of the interaction of corrosion microcells in presence and in absence of a corrosion inhibitor. The corrosion dynamic shows a complex nature. The interaction among corrosion micro-cells changes depends on a localization index (LI). A higher L_I implies a more discrete distribution of corrosion micro-cells along with a significant interaction, and a corrosion system auto-organization.

In this work, a series of durability requirements are proposed for the construction of long-service-life reinforced concrete (RC) structures in a coastal environment with extreme atmospheric corrosivity. RC specimens were exposed in a coastal outdoor site in Cuba for three years. Carbon steel corrosion evaluation revealed an annual average atmospheric corrosion rate over the maximum limit established (ISO 9223:2012) for extreme (CX) atmospheric corrosivity. The service life of the RC structures, considered as the sum of the time-to-corrosion-initiation and time-to-corrosion-induced concrete cracking, was determined as a function of durability requirements. The most important durability requirements to achieve a long service life (>70 years) in RC structures subjected to a CX corrosivity category were defined as follows: water/cement ratio, compressive strength, percentage of effective capillary porosity, and concrete cover thickness. Under these hostile environments, the expansion of the corrosion products formed on the reinforcement steel and the induced cracking of the concrete could be attributed partially to the formation of the akaganeite phase in reinforcement steel, which revealed a different morphology compared to the akaganeite typically formed in bare carbon steels.