STRATEGY AND DESIGN OF ANCHORAGE SYSTEM IN PBO-PRESTRESSING UPGRADING TECHNIQUE

摘要

This paper firstly introduces an innovative strengthening system with externally bonded prestressed PBO (short for Poly-p-phenylene-Benzobisoxazole) fiber reinforced polymer (PFRP) sheets, which present equal or higher strength and stiffness in comparison with high strength type of carbon fiber reinforced polymer (CFRP) sheets and great performance in energy absorption superior to the other fiber reinforced polymer (FRP) sheets such as aramid and carbon FRP sheets. Secondly, to avoid the debonding failure around the end of prestressed sheets due to a high interfacial shear stress, an effective anchorage treatment along with a design approach based on the concept of non-linear fracture mechanics are proposed. Moreover, an experimental approach was also proposed to identify the bond capacity at the end of prestressed PFRP sheets. The main parameters studied experimentally are the size and number of PFRP sheets.