Composite-Wedge Anchorage for Fiber-Reinforced Polymer Tendons

A novel composite-wedge anchorage is proposed here for prestressing fiber-reinforced polymer (FRP) tendons. The composite wedge was designed and optimized in terms of the length and elastic modulus of the wedge segments via finite-element analysis. The manufacturing technologies for the composite wedge involving a molding process, are presented in detail. Static, creep, and fatigue tests on basalt FRP (BFRP) tendons with the proposed anchorages were conducted. The tensile capacity, long-term deformation, and fatigue life of the tendon-anchor assemblies were analyzed. The experimental results show that the proposed anchorage exhibits an anchor efficiency factor of up to 91%; the corresponding value for a conventional steel-wedge anchorage is only 80%. The tendon-anchor assembly displays a creep behavior similar to that of BFRP tendons. Furthermore, the system survives 200 million cycles of fatigue load at a maximum fatigue load of 0.5 F-u (F-u is the tensile capacity of the tendon-anchor assembly) and a load range of 0.05 F-u. Wedge-sleeve and tendon-wedge sliding under a sustained load or cyclic load cannot cause considerable prestress loss in practical engineering. The results validate the effectiveness of the proposed anchorage under service loads and demonstrate the application prospects of this anchorage.