Pull-out behavior of CFRP single-strap ground anchors

Pull-out experiments were performed on four carbon fiber-reinforced polymer (CFRP) ground anchors simulating their applications in rock and soil. The CFRP tendons used in these anchors comprise a single-strap end on both the ground and air sides. On the ground side, the single-strap end is embedded in a cylinder of high-strength grout which fits into the borehole. In rock applications, the ground-side anchor can be used directly without additional confinement, while in the case of soil, an additional CFRP confinement ring is needed to prevent premature failure in the strap region. The load transfer from the strap to the grout cylinder occurs progressively; approximately 50% of the load is transferred at the semicircular strap end while the remaining 50% are transferred at the curved transition from the strap to the rod geometry of the free length.