Monitoring and characterizing the debonding in CFRP retrofitted RC beams using acoustic emission technology

Abstract

Reinforced concrete (RC) beams are retrofitted in flexure using externally bonded CFRP sheets to enhance strength and ductility. However, the strength of the CFRP is not completely utilized because of the debonding failure which is abrupt in nature. Additionally, the presence of interfacial defects further exacerbates the bond capacity. To ensure structural safety, continuous monitoring of the retrofitted members is necessary. Acoustic emission technology is the most feasible option for monitoring because of its non-invasive nature and continuous monitoring capability. Therefore, the capability of acoustic emission technology in detecting the debonding mechanism has been experimentally investigated. Furthermore, the effect of interfacial defects on debonding has also been studied. Three RC beams tested in flexure and monitored using acoustic emissions. It was found that the complex debonding mechanism can be detected and characterized using acoustic emissions and the presence of interfacial defects contributes to the debonding mechanism.

Keywords

• AE technology
• Interfacial defects
• Interfacial flexural cracks
• Flexural retrofit
• Acoustic emissions
• Crack characterization