Estudo do desempenho de vigas em situação de incêndio a partir do modelo de fibras

This paper presents the numerical analysis of reinforced concrete beams with rectangular and T sections and of steel-concrete composite beams subjected to high temperatures. To obtain the numerical results, which refer to the moment x curvature relations for different temperatures, as well as the maximum values achieved for the bending moments, it was used the fibers method or fibers model, with the constitutive relations of materials (concrete and steel) defined by the considerations of the EUROCODE 2 part 1.2 and by the ABNT NBR 15200. From the results obtained, which are compared with the responses of analytical expressions defined by ABNT NBR 6118 and by ABNT NBR 8800, it is possible to identify the residual strength of the structure as the fire exposure time increases and also demonstrate the effective reduction of its rigidity.