Load Testing of an FRP Bridge Deck on a Truss Bridge

New York State has constructed a fiber reinforced polymer (FRP) bridge deck as an experimental project. The goal of the project was to improve the load rating of a 50-yr old truss bridge located in Wellsburg, New York. The FRP deck weighs approximately 80-percent less than the deteriorated concrete bridge deck it replaced. Reducing the dead load increased the allowable live load capacity of the bridge without significant repair work to the existing superstructure, thus lengthening its service life. Load testing was conducted after installation of the FRP deck to study the conservativeness of the design, ascertain the assumptions made on composite action between the deck and the superstructure, and examine the effectiveness of joints in load transfer. This report describes the testing and discusses the results. The results indicate that the design was conservative. The design assumed no composite action between the deck and the superstructure, and the experimental data confirms that assumption. The study also shows that the joints are only partially-effective in load transfer between panels. Peak strains under the test loads were only a very small fraction of the ultimate strength of the FRP deck.