Added value of monitoring for the maintenance of a reinforced concrete wharf with spatial variability of chloride content: a practical implementation

Abstract

With 80% of European trade exchange and a key role for European defence, harbours play a major socio-economic role. Inspection of wharves is very expensive due to the difficult access to some components. Reinforced Concrete (RC) structures in harbours are designed for a long service life (50 to 70 years). For RC structures exposed to marine environments, chloride-induced corrosion leads to deteriorations. On-site corrosion diagnosis of RC structures typically consists of Non-Destructive (NDT) and Semi-Destructive Testing (SDT) with large uncertainties and sensitivity to environmental conditions (temperature, relative humidity). Moreover, spatial variability of deteriorations explains why weak parts of the component exist, i.e. those to be repaired or monitored. That requires more inspection for detecting the location of these parts. Embedded sensors reduce these drawbacks, but they involve an additional cost for installation and data treatment. This article analyses the added value of Structural Health Monitoring (SHM) by comparing the maintenance of a RC wharf with SHM to an optimized maintenance based on SDT only. Uncertainty of measurements and its effect on decisions are accounted for. It is shown that the savings on inspection and maintenance with SHM can reach more than 30%.

Keywords:

• Structural health monitoring
• value of information
• chloride induced corrosion
• gamma processes
• maintenance
• wharfs
• reinforced concrete

Acknowledgements

The authors would like to thank all the partners of iMAREO2 project: Keops Automation (D. Follut, D. Olivier), Université de Nantes (M. Roche), Nantes—Saint Nazaire Port (P. Lijour, M. Labegorre) and Bouygues Construction (the teams of Bouygues Travaux Publics Régions France). Special thanks are due to Thierry Giorgetti (acquisition unit installation) and Antoine Bassil (sensors installation) for their help in this project. The authors would like to thank the Pays de la Loire region for its financial support and Nicholas Gooding for the editing checking of the article.

Disclosure statement

No potential conflict of interest was reported by the authors.