Interfacial imperfection detection for steel-concrete composite structures using NDT techniques: A state-of-the-art review

Currently, the steel–concrete composite structures (SCCSs) have been widely applied as primary load-bearing members owing to their excellent structural behavior. However, due to the comprehensive influence of cyclic loading, periodical temperature, unscientific pouring process and severe corrosive service environment, interfacial imperfections including bond-slip and debonding defects occur, resulting in the deterioration of serviceability and durability. Therefore, it is urgent to develop effective nondestructive testing (NDT) methods for SCCSs to guarantee their mechanical performance and structural safety. In this study, a state-of-the-art review on existing interfacial imperfection detection technologies for SCCSs using NDT techniques is conducted. The typical structural type of SCCSs and characteristics of interfacial imperfections are reviewed first. The basic detection principle and mechanism of direct measuring and empirical methods, smart materials and sensors-based NDT technology, as well as corresponding typical applications, are comparatively discussed in detail. More particularly, the stress wave-based NDT testing is separately discussed, owing to its extensive application in recent years. In addition, the advantages and disadvantages, similarities and differences between various NDT methods are systematically compared and analyzed in depth. The research findings can provide constructive guidance for the scientific optimization of future experimental study and essential guidance to practical NDT testing on SCCSs.