Moisture and corrosion monitoring in concrete: On site electrochemistry Vs Evanescent field dielectrometry

Marie-Victoire, Elisabeth; LRMH; France

Victoire, E.M.; Laboratory of research on historical monuments; France
Bouischou, M.; Laboratory of research on historical monuments; France
Olmi, R.; IFAC-CNR; Italy
Riminesi, C.; ICVBV-CNR; Italy
Bouteiller, V.; Université Paris-Est; France

ID: ECNDT-0626-2018
Download: PDF
Session: Structural Health Monitoring 2
Room: H1
Date: 2018-06-12
Time: 15:20 - 15:40

In the field of historic concrete, the most deleterious decay mechanism is rebars corrosion. Therefore, it is crucial to be able to detect corrosion, or conditions necessary to generate corrosion, such as moisture content. As the main non-destructive onsite diagnosis tools for reinforced concrete, which are based on electrochemistry, can be disturbed either by intrinsic (salts content…) or extrinsic parameters (environmental conditions), it appeared interesting to explore alternative methods. In that aim for a few years, a new technique, based on evanescent field dielectrometry (SUSI©), is being developed to monitor water and salt presence in concrete.
The aim of this study was to compare the performances of the SUSI© system to that of standard electrochemical ones (resistitvity, potential and linear polarization resistance, performed with a Gecor©10 and Wenner probe), for the detection of the risk of corrosion in concrete exhibiting different types of pollution. In that purpose both types of techniques were tested on reinforced concrete slabs of the same concrete, either artificially carbonated, or polluted by chlorides (introduced in the mix of by wet-dry cycles). Tests were performed outdoors, in similar environmental conditions for all the slabs.
The first results confirmed the added value of the EFD technique as it was able to produce information both on moisture and salt contents.