Influence of plate length and anchor position on FRP-to-concrete joints anchored with FRP anchors

This paper presents the details of an experimental and analytical study that addresses the influence of fibre-reinforced polymer (FRP) anchors upon the strength and behaviour of FRP-to-concrete bonded interfaces. Single-shear joints are utilised to represent the bonded interface. The primary variables under consideration are (i) the influence of anchor position in relation to the loaded end of the joint, l_anc, (ii) the length of plate between the anchor and the unloaded plate end, l_end, and (iii) total length of plate, l_frp. These variables, which have received limited direct attention to date by the research community, are important parameters for understanding the influence of concrete cracking upon the behaviour of the FRP strengthening systems containing anchorage devices. The results of forty-one anchored joints and two unanchored control joints are presented and it is shown that l_end is more influential than l_anc. Details of a partial interaction model are also presented and the model is shown to adequately replicate the load, slip and strain distribution responses of a selected test joint.