An efficiency framework for anchorage devices used to enhance the performance of FRP strengthened RC members

Concrete structures strengthened with fibre reinforced polymer (FRP) composites in both flexure shear can be enhanced by introducing anchorage systems to suppress or delay the occurrence of premature FRP debonding. Research has demonstrated that by ultilising FRP anchors, it is possible to increase FRP utilisation levels prior to failure resulting in greater degrees of strengthening using less material. Despite several independent research studies conducted to explore the benefits of FRP anchors, there remains a lack of design guidelines which enable the specification of anchors in strengthening projects worldwide. However, prior to the development of such models, a database is required which compiles the relevant influencing parameters and corresponding FRP strains for given anchor types. The objective of this paper is to provide an extensive and up to date database as well as an evaluation framework based on anchor efficiency whereby the effectiveness of each type of anchor can be clearly determined. Anchorage efficiency factors are developed for multiple FRP anchorage systems for both shear and flexure applications based on a database of over 375 experimental data points.