Modelling electrochemical performance of reinforced concrete in natural marine airborne exposure environments: DURACON project-10 years evaluation

This research evaluation consisted of a detailed statistical analysis of the recorded data in 72 reinforced concrete specimens, from 12 natural test sites (in nine countries) located in chloride-laden environments (marine airborne-exposure, test sites located between 50-250 m from seashore), during a natural exposure period of 10 years. The parameters evaluated included the concrete physical-mechanical characteristics; meteorochemical information; natural reinforcing steel´s instantaneous corrosion current density (icorr) and cumulative icorr; concrete chloride concentration; surface crack width and rebar cross section loss correlations. This statistical analysis resulted in empirical instantaneous icorr predictions as a function of the exposure microclimates, through linear multiple regressions. These models showed a high linear dependence of the cumulative icorr with the concrete capillary absorption as well as with the meteorochemical parameters. Results obtained in this investigation showed higher corrosion aggressiveness of tropical environments when compared to the non-tropical ones. The cumulative icorr proved to be an effective tool to indicate the corrosive likelihood and to differentiate the stages of Tuutti´s service life model.