Use of electromagnetic non‐destructive techniques for monitoring water and chloride ingress into concrete

Abstract

ABSTRACT This paper deals with the use of three electromagnetic non‐destructive in situ techniques to assess concrete conditions: electrical resistivity, capacimetry, and ground‐penetrating radar. It shows the potential of these methods to monitor the ingress of water and chlorides into concrete. The electromagnetic properties that are studied here are dielectric permittivity and electrical resistivity, both sensitive to volumetric water content and chloride content. Results are presented from an experimental study conducted on concrete slabs (and corresponding core cylinders) in a controlled laboratory environment. Then, the discussion is focused on the ability of three electromagnetic techniques to assess the depth of the ingress front of different salt solutions and to discern between the 3 NaCl concentrations (0, 15 and 30 g/L).