Quantification of delamination in a composite floor using a novel damage index

The delamination of concrete from steel decking will reduce the strength and decrease the stiffness of the composite slab. Visual monitoring of delamination is typically not possible in many cases. A possible alternative is ultrasonic-based health monitoring. In this study, a novel damage index (DI) based on the absolute energy change (AEC) of the ultrasonic waves is adopted to quantify delamination damage in the composite floor. AEC-DI was constructed based on the decomposed signals provided by the wavelet transform. The monitoring process of the composite floor was conducted ultrasonically under flexural loading. An ultrasonic surface (Rayleigh) wave is employed for damage detection using gel-coupled piezoceramic sensors. The results revealed that the reliability and accuracy of AEC-DI in detecting composite floor separation is better than that of RMSD-DI.