About the research
The main objective of this research project was to develop a cost-effective life-cycle treatment plan for the preservation of Wisconsin bridge decks. The research team identified a comprehensive list of strategies through a review of current practice and department of transportation (DOT) policies and provided data-driven estimates of the performance and ideal timing of treatments with respect to condition by analyzing historic bridge condition data from the Wisconsin DOT (WisDOT) and other state DOTs and by considering engineering economics principles.
The scope of work included, in part,a literature review and a survey of Midwest states on the selection, implementation, and performance of deck preservation treatments. Initial email surveys were followed up by phone interviews. Detailed findings from these efforts are presented in Appendix A of this report and earlier intermediary reports to WisDOT. The major task for this project was to gather an archive of deck overlay and sealant history for Wisconsin decks and analyze these data in conjunction with historic deck conditions. Similar but limited data sets from South Dakota and Minnesota were also analyzed for the same purpose. The most common deck treatment plans that were observed in the data set were contrasted both for performance and cost-effectiveness in order to identify the most cost-effective treatment options for different deck conditions and at different points throughout a deck’s life cycle. To the authors’ knowledge, the work presented is the most comprehensive data analysis on deck preservation treatment performance by a state agency.
Regardless of the treatment, treated decks have consistently lower life-cycle costs than untreated decks. Sealing and overlaying decks as early as possible in the life cycle lead to lower life-cycle costs. Multiple applications of deck seals are cost-effective, particularly on high-traffic corridors. The treatment plans with simulated life-cycle costs can be considered by state agencies as they develop deck preservation plans.