Wave Propagation and Scattering due to Debonding in CFRP Strengthened Reinforced Concrete Beams

Abstract

Carbon fibre reinforced polymer (CFRP) systems as sheets or plates are commonly used to strengthen and retrofit damaged reinforced concrete beams. In general, the bond between the FRP element and concrete defines the effectiveness of the externally bonded FRP materials. In most cases, the interface bonding behaviour is usually tested via static loading conditions. In this paper, the bonding is verified under dynamic conditions. Wave propagation is modelled in delaminated CFRP strengthened reinforced concrete beam. First, the Wave Finite Element (WFE) is applied to predict the wave characteristics of the waveguides. Having established free wave solutions, one can couple it to a damaged segment that can be modelled in FE. The bond–slip model is used to simulate the CFRP to concrete interface bonding behaviour. Then, wave scattering characteristics are identified at the damaged section. Partial loss of debonding results in high refection coefficient of higher order modes. This study can lead to further advance based damage detection techniques related to debonding of FRP element to concrete with no required access to the FRP lamina.