A New Bond-Slip Model of Hybrid Bonded FRP-to-Concrete Joints

The dowel effect in hybrid bonded fiber reinforced plastic (HB-FRP) to concrete joints is difficult to quantify and make the anchoring joint instability. A new HB-FRP joint was built, which eliminates bonding between steel and FRP plates. Based on an empirical model of external bonding FRP (EB-FRP) to concrete joints and the new model of slip at debonding, the new unified bond-slip model of the HB-FRP joints is proposed. The parameters that affect the bond-slip model are analyzed. Pull-off tests are conducted for eight specimens with different numbers of mechanical fasteners, which has verified the proposed model. The load-slip relationship at the loaded end of the FRP plate was well predicted by the partial interaction numerical calculation and further verify the theoretical model.