Abstract
In Brazil, reinforced concrete structures designed based on NBR 6118 [1[1] ASSOCIAÇÃO BRASILEIRA DE NORMAS TÉCNICAS (ABNT). NBR 6118: Projeto de estruturas de concreto - Procedimento. Rio de Janeiro, 2014.] must be assessed in fire conditions through NBR 15200 [2[2] ASSOCIAÇÃO BRASILEIRA DE NORMAS TÉCNICAS (ABNT). NBR 15200: Projeto de estruturas de concreto em situação de incêndio. Rio de Janeiro, 2012.], which proposes multiple test methods. Concerning beams, this standard offers the tabular and simplified methods as possible choices. This study aimed to compare these two methods by applying their principles to isostatic and hyperstatic beams with section of 20x50 cm, designed at room temperature according to NBR 6118 [1[1] ASSOCIAÇÃO BRASILEIRA DE NORMAS TÉCNICAS (ABNT). NBR 6118: Projeto de estruturas de concreto - Procedimento. Rio de Janeiro, 2014.]. The temperature distribution along sections was obtained by means of a software program. The results from this study indicated that the simplified method yielded higher fire-resistance ratings (FRR) in 75% of cases, although not surpassing the tabular method by 30 minutes. The simplified method allowed an optimization of the results, despite the longer design time.
Keywords:
reinforced concrete in fire conditions; fire; structural design; NBR 15200
