Flexural behavior of prestressed FRP tubular bridge deck

An experimental and analytical study was undertaken to assess the flexural behavior of a new fiber reinforced polymer (FRP) deck system. The deck consists of a series of pultruted FRP tubes, post-tensioned in between each two stringers. Seven pure compression tests and eleven flexural tests were carried out to investigate the effect of tube size, bonding condition, post-tensioning, and supporting conditions. Finite element modeling of compression and flexural specimens was carried out to determine the effect of tube interface friction, bond and geometry restraints. The study showed feasibility of the new deck system for bridges with closely spaced stringers, where lack of two-way panel action is not a primary concern. Failure modes were also identified for these types of deck systems. Longer span decks generally failed in bending, whereas shorter span decks suffered from local shear failure at the corner of the tubes. Prestressing provided redundancy and reserved strength to the deck system.