Derivation and verification of a constitutive model for FRP anchors

Premature debonding failure limits the effectiveness of fibre-reinforced polymer (FRP) composites when bonded onto the surfaces of concrete members as a repair or strengthening measure. The FRP can debond at strains considerably lower (e.g. 20 %) of the strain capacity of the FRP. The addition of anchorage devices made from FRP (herein FRP anchors) has been shown to significantly increase the utilisation of the FRP strengthening and the ductility of the FRP-strengthened element. No constitutive models currently exist though with which to quantify the strength and behaviour of FRP anchors. This paper therefore reports the development of a load-slip model for FRP anchors based on a series of tests on single-shear FRP-to-concrete joints anchored with FRP anchors that have been undertaken by the authors and reported in other studies. The FRP anchor model is then incorporated into a partial interaction model upon which the response of a selected test joint is simulated.