Evaluation of chloride ion penetration through concrete surface electrical resistivity of field naturally degraded structures present in marine environment

Abstract

As reinforcement corrosion due to chlorides action is the main cause degradation of reinforced concrete structures in marine environment, concrete electrical resistivity has been used as a non-destructive methodology in order to evaluate the service life of these structures, since it is a simple and fast field methodology that presents confiable results. At this point, many works have been carried out in order to stablish a correlation between concrete electrical resistivity and chlorides penetration. However, observing the literature and standards about this issue it was noted significant differeces between the values presented for stablish this correlation. Furthermore, a significant part of the literature studies were conducted under controlled laboratory conditions, which can differ from the real aggressiveness that a structure is exposed. Thus, this paper presents a new proposal of range values and classes between the chlorides penetration and the concrete surface electrical resistivity, based on the analysis of real chloride profiles from structures present for more than 40 years in different marine aggressive zones under natural degradation. The results shown that standard parameters were close from the values proposed in this work; however a refinement in the range values and the insertion of new parameter classes are necessary for better evaluation of chlorides penetration in concrete structures present in marine environment.