Optimal design of external rings for confined CFST columns

摘要

Concrete-filled steel tube (CFST) columns are becoming increasingly popular in the construction of tall buildings due to their superior behaviour contributed by composite action. However, this composite action cannot be fully developed owing to the imperfect steel-concrete interface bonding that occurs in the elastic stage. To overcome this problem, external rings were adopted in this study. To further improve the efficiency of external rings, different configurations of steel rings were tested.