Equivalent load of reinforced concrete columns under fire

Purpose – The fire response of structural reinforced concrete columns is usually justified by the reduction in ultimate load bearing capacity. This is due to the decrease in mechanical strength of steel and concrete upon exposure to a fire. In structural design, it is more desirable to consider the action of load directly. The concept of equivalent accidental load due to a fire might give more convenient structural design data. This paper aims to focus on these issues.Design/methodology/approach – A theoretical analysis for the equivalent accidental load imposed on reinforced concrete columns (axially loaded columns, uniaxially loaded columns and biaxially loaded columns) exposed to four‐side fires is carried out. The test results of previous research are used as examples and for checking computations. After determining its temperature field, the equivalent accidental load due to fire is calculated using simplified methods. The fire resistance period of reinforced concrete columns can also be determined.F...