FRP-Concrete Bond Behavior: A Parametric Study Through Pull-Off Testing

Synopsis: The sensitivity of the FRP-concrete bond failure load to changes in geometric and material parameters is described, and initial comparisons to predictions from existing bond models are made. To accomplish this, load and strain data from a series of single-lap pull-off tests is analyzed, in which carbon fiber reinforced polymer (CFRP) strips of varying width, thickness, and bonded length were pulled from concrete blocks of varying concrete strength. It was found that the concrete compressive strength had limited effects on the bond failure load, and longer bonded lengths increased the time up to failure load. Changes to the bonded width and FRP thickness had a significant impact on the bond failure load. Failure load predictions produced by three studied bond models were found to be strongly influenced by the material properties used as input, and were occasionally insensitive to the parameters varied.