Tensile Behavior of FRP Tendons for Prestressed Ground Anchors

The research work reported in this paper involves investigation of the tensile behavior of fiber-reinforced polymer (FRP) ground anchors. Variables of the tests on the anchor models were anchor fixed length, tendon type, and tendon constituent. Sixteen monorod and four multirod grouted aramid FRP (AFRP) (Arapree and Technora) and carbon FRP (CFRP) (CFCC and Leadline) anchors were tested according to standard methods of tensile tests and sustained load tests under different load levels. Test results indicated that AFRP Arapree and Technora monorod anchors showed higher displacement and slip in comparison with CFRP CFCC and Leadline anchors. Technora anchors failed because of the detaching of winding fibers from the core of the rod. CFRP anchors had a higher tensile capacity and lower creep displacement than AFRP anchors. All the tested CFRP monorod and FRP multirod anchors with a 1,000-mm fixed length appeared to have an acceptable tensile behavior according to existing codes. Creep behavior appeared to control the long-term tensile capacity of prestressed FRP ground anchors. The recommended working load for prestressed FRP ground anchors is 0.40fpu for AFRP rods and 0.50fpu for CFRP rods, where fpu is the ultimate load or strength of anchor tendons.