Review of Design Guidelines on Flexural Strengthening of RC Beams with FRP Composites

Abstract

Reinforced concrete (RC) beams can be strengthened in flexure by bonding fibre reinforced polymer (FRP) composites to their tension face. This concept is relatively simple as the FRP essentially acts as an extra layer of reinforcement and superficially the analysis may be assumed to be based on existing RC beam design principles. The analysis is however considerably more complicated due to premature failure by separation or debonding of the FRP from the concrete substrate. Practicing engineers in Australia faced with the prospect of designing FRP strengthening measures for RC beams are forced to select from a host of design guidelines around the world as no Australian guideline currently exists. This paper will summarise and objectively compare five commonly consulted design guidelines. It will also unify the design guidelines using a consistent seter notation and terminology, All design guidelines are found to be based on traditional RC design principles although their treatment of debonding varies.