Computational modeling of the thermal effects on composite slabs under fire conditions

This paper presents finite element thermal models to evaluate the thermal behavior of composite slabs with steel deck, submitted to standard fire exposure. Composite steel/concrete slabs are a mix of a reinforced concrete layer with a profiled steel deck reinforced by steel bars between its ribs. The resulting transient and non-linear thermal problems are solved numerically with threedimensional multi-domain finite element models. The models were developed for normal weight concrete and lightweight concrete, and for different steel deck geometries (trapezoidal and re-entrant). The results of the numerical simulations are used to present a new calculation method to determinate the temperatures on the steel deck components and on the rebars and, consequently, to determine the bending resistance of composite slabs under fire conditions.This work has been supported by FCT - Fundaçãoo para a Ciência e Tecnologia within the Project Scope: UIDB/05757/2020