A new bond-type anchorage system for prestressed applications with FRP tendons

Corrosion resistance, high strength and advantageous strength-to-weight ratio enable FRP composites to be potential replacement for steel tendons in prestressed applications. One of the obstacles for FRP tendons to be widely used for post-tensioning structures is regarding the methodology to anchor the FRP tendons and to maintain the post-tensioning force during the service life of the structures. High ratios for tensile to compression and to shear strength make it necessary to develop a new anchorage design concept for FRP tendons. Recently a new bond-type anchorage system has been developed at the University of Sherbrooke for prestressed applications of FRP multirod tendons in bridges, structures, and ground anchors. The system is convenient and economical, and easily fabricated and assembled. The performance and anchoring capacities have been tested and analyzed. The paper presents pullout behaviour of the anchorage systems for CFRP mono- and 9-rod tendons. The strain monitoring results from strain gauges installed on the surface of anchorage and CFRP rods are also given. Test results show that the developed anchorage system is capable of giving at least 95% of the tensile strength of FRP multirod tendons. It is proposed to use bond-type anchorage with sand-cement grout to anchor FRP multirod tendons. It is recommended that the design working load should be less than 45% of the short-term ultimate tensile strength of carbon FRP tendons, taking into account the environmental and sustained load effects during the service life.