The AASHTO Guide Specification for Service Life Design of Highway Bridges and Guide to Bridge Preservation Actions have made a tremendous impact on the ability to design concrete structures for a service life goal. However, current service life design provisions for structural steel take the form of deemed-to-satisfy provisions. More efficient and economical designs could be achieved by developing a deterioration model based on principles of steel corrosion and coating performance. The model would allow steel to be sized based on the service life demands (e.g., exposure conditions) in addition to the structural loads. Research is necessary to validate the models against in-service performance.

The objective of this research is to develop a credible, useful, and dynamic deterioration model that can be used by all levels of a public transportation agency to make informed decisions regarding corrosion prevention of steel bridges across the range of conditions in the United States. The model would form the basis of a partial factor method for the service life design of steel bridge structures. The model would account for the performance of corrosion prevention strategies, allowing the designer to evaluate the service life implications of alternative materials in different exposure conditions. The model would also inform maintenance and rehabilitation planning by helping to determine the timing and frequency of preservation actions.