Numerical Study on the Failure of Reinforced Concrete Columns Exposed to Fire Including Cooling Phase

It is evident that reinforced concrete (RC) structures exposed to fire can fail during cooling phase, causing significant dangers to firefighters and residents who enter the building after fire has been extinguished. It is therefore necessary to investigate the failure of RC structures exposed to fires with consideration of cooling phase. This paper presents a quantitative study on the delay in failure time of RC columns subjected to natural fires including the cooling phase. Numerical studies on the behavior of those RC columns were performed using SAFIR software. Both standard fire curve and natural fire curve including cooling phase were analyzed in the research, which also involves a parametric study on the influence of different factors (heating time, load ratio, and concrete cover thickness) on the delay in failure time of RC columns.