Corrosion level estimation by means of the surface crack width

Since the concrete cover cracking is the earliest visible manifestation of corrosion, a relationship between crack opening and corrosion level can be a useful non-destructive tool to estimate the degradation level of an existing RC member. In the present paper, the predictive formulations available in the scientific literature estimating the crack width due to a given corrosion level are accurately described and their reliability is evaluated by a statistical analysis of the error in the predictions. At this aim, an extensive dataset on crack openings of artificially corroded RC specimen reinforced with a single bar, or more bars with large spacing, has been collected. Finally, a novel relationship for the assessment of the corrosion degradation from the surface cracking is presented and validated.