Reliability analysis of simply supported RC beam cross-sections in a fire situation according to Brazilian standards

Abstract

Abstract This article aims to evaluate the reliability of cross-sections of simply supported reinforced concrete (RC) beams in a fire situation considering the utilization of the simplified method proposed in the Brazilian standard NBR 15200 [1]. The impact of the concrete cover, the live-to-total load ratio, and the quantity of heated beam faces were all taken into account in this analysis. Besides, a sensitivity analysis is performed showing the random variables that are of major impact on reliability. In the end, it was concluded that the number of heated faces of the beam is very important to the safety of these structures. Also, it is found that a higher concrete cover can promote an increase in reliability and that a bigger proportion of live load relative to the total load generates a decrease in the probability of failure. Regarding the sensitivity analysis, the fire temperature and the concrete cover were the variables with the greatest observed impact.