A fracture-mechanics model for debonding of external fibre reinforced polymer plates on reinforced concrete beams

Abstract

A Fracture-mechanics model for debonding of external fibre reinforced polymer plates on reinforced concrete beams is presented. The conventional methods of concrete-FRP interface analysis use finite element models, which require details of unknown and unknowable interface characteristics. The present model assumes flaws in the vicinity of the interface and assesses whether sufficient energy can be released to cause these flaws to propagate. Energy released by an extension of an existing flaw depends on the change of recoverable energy stored in the system. This paper concentrates on the moment-curvature model for a cracked reinforced-concrete beam under a prestress caused by the force in a FRP plate. The use of the proposed model to determine the energy released from the system with the extension of an existing flaw is also presented. The energy required to create the associated new surfaces depends on interface fracture energy which is first reviewed and methods to determine is also discussed