Abstract: The current codes have no clear provisions on how to carry out effective fire protection design for external concrete-filled steel tube columns and their joints located out of the external wall system for super high-rise buildings. In this paper, the joint of external concrete-filled steel tubular columns in a super high-rise building was studied. Based on FDS simulation, the most severe temperature curve for the external joint was determined, the mechanical performance and fire resistance rating of the joint were calculated, and the fire protection design of the external joint node was also proposed. Furthermore, fire resistance test was conducted to examine the temperature raise of the joint, and the test results align well with theoretical calculations. As a result, the effectiveness of the fire protection for the joint node was verified.

Key words: concrete-filled steel tube column, external joint, fire protection, time-temperature curve, fire resistance test