Experimental study and failure mechanism analysis at the meso-scale of the fatigue performance of a CFRP tendon novel composite anchorage

Abstract

This paper investigates the fatigue performance of CFRP tendon novel composite anchorages. The fatigue mode of the novel composite anchorage was analysed. Furthermore, based on the meso-morphology of the contact surface between tendons and epoxy resin, the fatigue mechanism of composite anchorage was explored. Finally, the effects of fatigue cyclic load on the slippage of tendons at both free end and loaded ends and clamps, the barrel strain and the stiffness of CFRP tendons were investigated. Results revealed that the novel composite anchorage can subject 2 million fatigue cycles load under 0.45 fu fatigue maximum stress and 200 MPa stress range. The failure modes of FS-2, FS-3 and FTD-1 specimens with fatigue failure were the damage of the contact surface between the tendons and the epoxy resin, which leads to the tendons slip out from the epoxy resin. Furthermore, the fatigue performance of the three-tendon specimens with dispersed anchoring was worse than that of the anchorage with parallel anchoring. Steel barrels and clamps can work effectively in all specimens, but the tendons stiffness increases slightly initially and then decreases rapidly. In summary, the novel composite anchorage has good fatigue performance and the potential for practical application.