A Three-Parameter Bond Strength Model for FRP-Concrete Interface

The success of most strengthening or retrofitting technologies for concrete structures by using external bonded FRP sheets depends highly on the interface bond between FRP sheets and concrete substrates. This article presents a simplified, but more rational and accurate three-parameter bond strength model for FRP-concrete interface based on statistical analysis, in which main parameters of bond strength behavior are considered. An extensive database consisting of 311 experimental data of simple FRP-to-concrete bonded joints has been assembled to calibrate the parameters of the proposed model and examine its validity. Then, the performance of the proposed model has been compared with the performance of other existing bond strength models using the assembled database. Results have confirmed the validity of the proposed model and shown its superiority over other existing models.