Fire behavior and performance of concrete-filled steel tubular columns: Review and discussion

This paper presents a review of the fire behavior and performance of concrete-filled steel tubular (CFST) columns. The motivation for the studies on the fire behavior of CFST columns is provided. The effects of many structural parameters on this fire behavior are reviewed and discussed. The equations in the current design codes for predicting the fire resistance capacity and residual axial load carrying capacity are summarized, and comparisons between the experimental results and the predicted results are performed. The discussion results indicate that the fire resistance capacity decreases with the increase in the slenderness ratio, axial load applied, and normal concrete strength, and with the decrease in the cross-sectional dimension and the ratio of reinforcing steel rebar to thickness of fire protection. The Chinese and North American codes provide reasonable prediction of the fire resistance of a CFST column, whereas the Japanese and the modified European codes overestimate the experimental results. Besides, the Chinese code and the Han model predict the residual axial load carrying capacity with better accuracy than the European and Japanese codes. Finally, recommendations for future studies are provided. (C) 2019 Published by Elsevier Ltd.