Behavior of concrete-encased concrete-filled steel tube columns under diverse loading conditions: A review of current trends and future prospects

AbstractThe concept of concrete-encased concrete-filled steel tube (CE-CFST) columns was conceived during the quest to enhance the safety of structures in high seismic regions. Over the past two decades, researchers have extensively investigated the performance of CE-CFST columns under a range of loading conditions using experimental, analytical, and numerical methods. Previous research has shown that integrating outer RC and encasing steel tubes into concrete-encased concrete-filled steel tube columns boosts their structural performance under a wide diversity of loading conditions. This paper aims to provide a comprehensive analysis of various models proposed by researchers in different regions and summarize all results that have been breakthroughs in the last decade. Researchers revealed that this type of structure only uses less than 85% of its flexural capacity. There are still significant research gaps in depicting these structures’ behavior under diverse loading conditions, both analytical, numerical and experimental. The authors show the highlights of CE-CFST columns’ performance and give a detailed review of the corresponding reinforced concrete (RC) columns and concrete-filled steel tube (CFST) columns. The highlights for further researches on CE-CFST are provided for elaborating other mechanical properties. To sum up, the CE-CFST composite columns provide resilient and sustainability in structure during engineering applications