Design and evaluation of a new bond-type anchorage system for fiber reinforced polymer tendons

Abstract

Corrosion resistance, high strength, and advantageous strength-to-weight ratio enable fiber reinforced polymers (FRPs) to have substantial potential to replace steel tendons in prestressed applications. One of the main technical obstacles to wide use of FRPs in the construction industry is the methodology to anchor FRP tendons to achieve their full strength. High tensile to compression and shear strength ratios make it necessary to develop a new anchorage design concept for FRP tendons. This paper gives a literature review of bond-type anchorage systems and the mechanics of stress transfer by bond from FRP tendons to grout and reports an experimental study on a newly developed bond-type anchorage system with carbon fiber reinforced polymer (CFRP) Leadline 8-mm-diameter rods. The test program consisted of nine monotonic tensile tests, two pullout tests, and two proving tests on the anchorage system with Leadline single- or 9-rod tendons. The test results showed that the developed anchorage system with 250-mm bond length ensures full development of the tensile strength of Leadline mono-rod tendons. The bond strength of Leadline 9-rod tendons is 14 MPa for a bond length of 95 mm, 62% of that of mono-rod ones with a bond length of 80 mm. The anchorage system with a 400-mm bond length gives at least 90% of the tensile strength of Leadline 9-rod tendons and also demonstrates an acceptable sustained loading behaviour in accordance with existing codes.Key words: anchorage, bond stress, creep, grout, polymers, rod, slip, tendon.