Galvanic corrosion is one of the most prevalent corrosion problems of modern times, and this paper presents tools and guides that enable bridge engineers to conduct better assessments of the corrosion risk in bridge design and management.
Based on a comprehensive experimental program, a galvanic series was developed that provides a systematic collection and comparison of the corrosion tendencies of bridge alloys. It has demonstrated that a significant galvanic corrosion tendency warrants attention but also revealed that a seemingly low tendency could lead to substantial galvanic corrosion between two actively corroding metals. These findings support the need for a method for further evaluation: a measurement of galvanic corrosion rate that assesses how fast the anodic alloy loses its mass. A set of criteria to interpret the magnitude of galvanic corrosion risk was established by considering both the galvanic corrosion rate, and a new concept of a ratio that takes account of the galvanic corrosion rate in the context of a general corrosion rate (gal/corr), providing a consistent assessment for the alloys studied in this project. These advancements subsequently enabled the development of a three-step guiding procedure for assessing galvanic corrosion. The experimental results also demonstrated the occurrence of galvanic corrosion to be materials-environment-configuration specific. In the future, it is recommended to develop a better understanding of the corrosion performance of bridge metals and alloys and systematically examine them in the way their mechanical properties are studied.