An anchoring element for prestressed FRP reinforcement: simplified design of the anchoring area

摘要

Today, fibre-reinforced polymers (FRP) are widely used construction materials. The use of non-metallic reinforcement as inner reinforcement has many advantages, as is well known, but there are some areas of application that need to be resolved in order to improve the usage of FRP reinforcement in real-world conditions. One of these is the design of a suitable anchorage for prestressed FRP applications. It is difficult to design a safe anchorage using conventional methods of anchoring (systems for the anchorage of steel tendons) due to the well-known low compressive strength perpendicular to the fibres, this being due to the anisotropy of composite materials. Most of the anchoring systems commonly used worldwide are based on the use of metal parts (steel tubes, wedges, etc.) in a system which is primarily designed to be non-metallic. It is in contradiction with the initial intention to use non-metallic reinforcement. The presented text describes the basic physical and mechanical properties of a developed non-metallic anchor element. The essential principles of an analytical solution of the developed anchoring element based on the stiffness parameters of the system's individual components are also presented. The behaviour of each material used is described in terms of simplify form. The functionality of the anchoring system was verified by a number of load tests and the obtained results were compared with theoretically and numerically calculated values. The presented results show the high efficiency of the anchoring system as well as the suitability of the derived analytical solution for simplified design and evaluation of the anchoring area.