Use of electromagnetic non-destructive techniques for monitoring the chloride ingress into concrete

This paper deals with the use of electromagnetic nondestructive in-situ techniques to assess concrete condition. It shows the potential of these methods to monitor the ingress of water and chlorides into cover concrete. The electromagnetic properties that are studied here are electrical resistivity and dielectric permittivity, both sensitive to volumetric water content and chloride content. Results from an experimental study conducted on concrete slabs (and corresponding core cylinders) in a controlled laboratory environment are presented. Then, the discussion is focused on the ability of three EM techniques to assess the depth of the ingress front of the different salt solutions and discern between their salt concentrations (0, 15 and 30 g/L).