Towards the Determination of Chloride Profiles by means of Resistivity Measurements in Reinforced Concrete

Abstract

Reinforced concrete (RC) structures, such wharfs or floating structures, are submitted to chloride ingress which can lead to rebar corrosion. Before the corrosion initiation, in a preventive point of view, engineers can be interested in non-destructive evaluation and inspection methods. In that way, electrical resistivity tomography is a promising tool to access to resistivity profiles then to chloride profiles in real RC structures in the future. We would like to present herein the advances in the necessary research developments to reach this goal, i.e. the resistivity profiles obtained in reinforced concrete slabs submitted to chloride ingress. The 4 slab dimensions are 90x70x13 cm. The specimens are cured, dried during 9 months then submitted to salted water imbibition during 4 months. Electrical resistivity tomography measurements are performed at short terms during 1 week of imbibition. The monitoring show that several phenomena influence the resistivity profiles such as the penetration of water and chloride ions. Meanwhile, steel rebar effect can be considered thus eliminated from electrical resistivity profiles following the method developed by (Alhajj et al. 2019).

Full document