Abstract
The use of hollow structural steel (HSS) columns filled with concrete has become widespread in the past few decades. The residual strength of a composite column may be used to assess the potential damage caused by fire and help to establish an approach to calculate the structural fire protection for minimum postfire repair. The behavior of 12 concrete-filled HSS columns with or without fire protection after exposure to the ISO-834 fire standard subjected to axial or eccentric loads has been experimentally investigated and the results presented in this paper. Comparisons are made with predicted column strengths using the existing codes such as LRFD-AISC-1994, AIJ-1997, EC4-1996, DL5085/T-1999, and GJB4142-2000. A mechanics model is developed in this paper for concrete-filled HSS columns after exposure to the ISO-834 fire standard, and is a development of the analysis used for ambient condition. The predicted load versus mid-span deflection relationship for the composite columns is in good agreement with te...