Advancements in interfacial bonding performance of concrete-filled steel tube members

To comprehensively grasp the interfacial bonding performance of concrete-filled steel tube (CFST) members, this paper reviews recent research on the bonding behavior of both traditional and novel CFST under normal or extreme environment conditions. The review spans experimental investigations, theoretical analyses, and numerical simulations. The bonding performance tests for CFST specimens, the influencing factors on interface bonding performance, and the strengthening measures are summarized. It provides a detailed analysis of the interfacial bonding mechanism in CFST specimens, evaluating the suitability of empirical formulas for interfacial bonding strength at both normal and elevated temperatures using existing experimental data. Additionally, the bond-slip constitutive relationships and numerical simulation methodologies for the CFST interface are also introduced. Summarizing the current research reveals that elucidating the bond damage mechanism in CFST specimens exposed to various factors, establishing localized bond-slip constitutive models for diverse CFST interface types, and developing precise and efficient numerical simulation techniques are key areas for future research. Moreover, the use of computer technology for in-depth analysis of sample data and the subsequent development of a prediction formula for CFST interfacial bond strength customized for engineering applications is crucial.