Tensile properties and pullout behaviour of AFRP and CFRP rods for grouted anchor applications

Abstract

Fiber-reinforced-plastic (FRP) rods have been introduced in the market for grouted ground anchors. The resistance to corrosion and chemical attack, high strength-to-weight ratio, and ease of handling of these rods make them a better alternative to steel tendons in some applications of ground anchors. However, to fully utilise FRP rods as tendons for cement grouted anchors, some aspects of their behaviour have to be determined, including tensile properties, tensile capacity, bond strength in cement grout, long-term strength and durability in alkaline environments. In this paper, the tensile characteristics, bond strength and pullout behaviour of AFRP and CFRP rods embedded in cement grout are discussed. The pullout test program involved four types of rods, four types of cement grouts and three types of anchorage tubes with three bonded lengths. The experimental results have shown that the tensile properties of the FRP rods are close to the manufacturers’ data. The surface geometry of FRP rods, the properties of the filling grout and the stiffness of the host medium (anchorage tube) influence the pullout behaviour, pullout capacity and maximum bond stress of cement grouted FRP anchors.