ABSTRACT
5.1 When the load ratio (n) of a CFDST column does not exceed the strength index (k t), no extra measures are needed for the fire-resistance design, where the load ratio (n) was defined as the ratio of the axial compressive load applied in the fire situation to the load-bearing capacity at ambient temperature. The strength indexes for CFDST columns subjected to different fire-resistance ratings can be obtained from Table 5.1.
