A North American Perspective on Service Life and Durability of Concrete Bridges

This paper describes the author’s views on durability and service life of concrete bridges in North America, considering the past, present and future. Historical materials and practices have resulted in disappointing durability and service life that does not meet modern expectations. In recent years formal service life analysis and prediction has been implemented as part of the design process for major projects, typically involving numerical modelling of time to corrosion, and mitigation or avoidance of other forms of deterioration by empirical methodology. These efforts are, however, hampered by a lack of an accepted service life design standard which is adapted to North American practice and materials. Work is under way to answer this need. In the future, further development is needed to provide a better match between expectations and reality, a more practical definition of “service life”, validation of design features implemented to mitigate or avoid deterioration for which there are no available time-based models, and improved validation of numerical modelling parameters that describe exposure conditions and material resistances.