Uncertainty assessment of concrete electrical resistivity measurements on a coastal bridge

Abstract

During the diagnosis of existing structures, errors can be generated by uncertainty of measurements. The latter is affected by several factors and should be evaluated on-site. In this paper, a large data of resistivity values (1800 measurements) measured on a bridge in a marine environment has been gathered utilising a four electrodes probe under specific procedures. The uncertainty assessment based on measurements repeatability or local material anisotropy and variability were characterised from this database. Moreover, considering the uncertainty results together with the corrosion risk from RILEM TC154 recommendation, probability of wrong assessment (PWA) is evaluated. Finally, the influence of uncertainty and PWA were discussed in order to help the owner of the bridge in taking decision on additional measurements or complementary investigations.

KEYWORDS:

• Resistivity measurements
• reinforced concrete
• marine environment
• uncertainty of measurements
• probabilistic modelling
• probability of corrosion
• diagnosis

Acknowledgments

The French project DéCoF-Ré (Décision Corrosion Fiabilité – Ré) is a cooperative research programme between several partners: IFSTTAR, Université de Nantes & Capacité SAS, Cerema (Ouest and Ile-de-France), SIXENSE Concrete and the Département de la Charente-Maritime. The authors acknowledge the owner of the Ré Bridge, the Département de la Charente-Maritime (A. Audouin-Dubreuil) and the company SIXENSE Concrete (M. Brouxel) for their financial supports. The authors are very grateful to R. Queguiner, S. Pasquiet, F. Landrin and J. Schneider from Cerema, W. Traverst and P. Boujard from IFSTTAR and M. Roche from Université de Nantes for performing the measurements and they also thank M. Barbier and his entire team (Département de la Charente-Maritime) for their help with the vessel.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1 Décision Corrosion Fiabilité – Pont de l'Ile de Ré