Theoretical and experimental analysis of FRP bridge deck under cold temperatures

The large temperature difference (~120°F) between the top and bottom of a fiber-reinforced polymer (FRP) bridge deck is attributed to low thermal conductivity of FRP materials and low thermal mass because of hollow core FRP decks. In this study, laboratory tests were conducted on glass FRP deck modules under low temperature gradient. A theoretical beam model was used to analyse the FRP deck-steel stringer system while closed form solutions (based on Macro Approach and Navier– Levy method) were derived using the plate bending theory for FRP deck modules. In addition, thermal stress evaluations from field test data were evaluated using theoretical models. The laboratory test data indicated that the FRP decks sag when they were subjected to negative temperature difference. Deflections and expansion of the deck top increased as the difference between the Ttop and Tbottom increased. Partial deck restraint, provided by steel stringers, resulted in partially induced stresses.