Field and laboratory tests for corrosion assessment of existing concrete bridges

Many existing Reinforced Concrete (RC) structures built around the middle of the last century have now reached the end of service life and require maintenance interventions to repair degradation-induced damage, especially due to steel corrosion. The conservation of existing structures and infrastructural facilities is therefore a relevant and urgent problem, particularly bridges and viaducts in view of their social and economic importance. In order to correctly define the restoration interventions and fulfill safety, robustness, and durability requirements, it is necessary to inspect RC structures and assess the state of degradation of materials and corrosion of embedded steel. This paper is aimed at contributing to effective methods, procedures, and criteria for corrosion assessment of existing RC bridges and viaducts. To this purpose, the results of inspections and diagnostics carried out on structural members of bridges subjected to corrosion and exposed to different environmental conditions and microclimates will be presented by focusing on in-field non-destructive testing as well as on chemical, physical and microstructural analyses.