Long-Term Durability of FRP Bond in the Midwest United States for Externally Strengthened Bridge Components

AbstractIn this study, the bond strength of a typical FRP system subjected to long-term natural weathering in the midwest United States is experimentally investigated, and the rate of degradation is estimated. To do this, the bond strength of a fiber-reinforced polymer (FRP) system exposed to over 15 years of weathering is determined with pull-off testing, and a relationship between strength reduction and exposure time is developed using regression analysis. For unweathered specimens, it was found that the attachment strength of the FRP system was governed by the concrete substrate, while for weathered specimens, the FRP system could detach by either a failure of the substrate, at the FRP/concrete interface, or FRP failure. It was found that a logarithmic curve best matches bond deterioration.