FRP post-tensioning of laminated timber bridges

In this paper, Glass Reinforced Plastic (GRP) tendons, rather than the commonly employed steel threaded bars, are used to post-tension a laminated wood deck. Monitoring of prestress forces after 260 days shows that properly designed GRP tendons can significantly reduce prestress losses. While initial results are encouraging, long term concerns with GRP tendons include creep-rupture in the E-glass reinforcement and environmental attack on the glass fibers. The paper also reviews some of the literature on creep-rupture of GRP.