Push-off strength of steel girder to fiber-reinforced polymer deck connections

Abstract

This study investigates the connection behavior between a steel girder and a fiber-reinforced polymer (FRP) bridge deck by conducting push-off tests on four specimens with the FRP deck. The FRP deck consists of a mechanically fastened pultruded FRP top plate to a bottom panel that includes four T sections and a flat bottom plate pultruded as one piece. The FRP deck panel was grouted to the steel girder using shear studs, which were welded on top of the girder at locations corresponding to every closed cell of the deck. For comparison, two additional deck specimens were made using grout with shear studs connected to the steel girder. Test parameters included the type of decks, number of studs, and diameter of studs. Specimens in tests exhibited a roughly 10-mm slip between the steel girder and deck before failure; failure modes were fracture of shear studs. Ultimate shear strength of the FRP deck-to-girder connection was overestimated per AASHTO LRFD bridge design specifications (2004) due to gout cell flexibility and bedding layer damage. A correlation study was performed using a nonlinear finite element analysis program. Based on experimental and analysis results, design recommendations were made for the FRP deck-to-steel girder connection.