Active Microwave Thermography: A Real-Time Monitoring Tool for CFRP-Concrete Bond Testing

Abstract

Nondestructive testing and evaluation (NDT&E) of materials and structures is important for many civil and infrastructure applications. To this end, this paper introduces active microwave thermography (AMT) as a real-time monitoring tool for detection of defect formation and propagation in composite-strengthened concrete structures. AMT is a thermographic NDT&E technique which utilizes microwave radiation as a heat source. In this case, AMT is used to detect and evaluate debonding in a number of concrete specimens which have been strengthened with externally bonded carbon-fiber-reinforced polymer (CFRP) composite. As microwave radiation can be constantly and continuously applied over a long period of time, it can be effectively used as a source of thermal energy for long inspections. Several measurement results are presented in the paper that support AMT as a successful monitoring tool for the aforementioned application.