Recent Developments in Long-Term Performance of FRP Composites and FRP-Concrete Interface

Abstract

This paper presents recent developments in long-term behavior of fiber reinforced polymer (FRP) composites and FRP-strengthened concrete beams with special emphasis on the FRP-concrete interface subjected to creep and fatigue loads. Although short-term behavior of FRP-strengthened structures is intensively reported thus far, their long-term performance has not been thoroughly elucidated yet. This state-of-the-art paper provides a synthesis of recent findings on the long-term performance of FRP composites and their time-dependent bond behavior for strengthening concrete structures, including externally-bonded FRP sheets and near-surface-mounted FRP strips. The review examines the bond-stress slip response, damage accumulation associated with progressive crack propagation, and failure modes, including descriptions of the predictive models. The identified research needs to further advance FRP-strengthening technologies are addressed.