Mechanical behavior of CFRP rod anchors under tensile loading

This paper presents the results of an experimental and numerical study to examine the mechanical behavior of carbon fiber reinforced polymer rods gripped by a wedge anchor, comprised of an aluminum sleeve, four stainless steel wedges, and a stainless steel barrel. The carbon fiber reinforced polymer rod-anchor system was tested under monotonic and cyclic loading conditions. In the static load tests, the effect of presetting loads, usage history, and sleeve material were investigated. Presetting load levels of 50, 65, 80, and 100 kN were used, and tests were conducted with new and reused anchors. Aluminum and copper sleeves were considered. As the presetting load increased, the displacement (or slip) of the rod and sleeve decreased. No significant effect of reusing the anchor was found other than replacing the sleeve. Anchors with copper sleeves performed poorly at low presetting loads, in comparison to aluminum sleeves. Cyclic load tests were conducted on anchors using aluminum sleeves with a presetting load of 80 kN. The effects of cycling on the rod and sleeve displacement were minor for different mean stresses and stress ratios. A finite-element model, consisting of three contact surfaces, was applied to simulate the anchor components; the displacement of the rod compared well with experimental results.