Piloto, Paulo A.G.Ribeiro, OtavioGidrão, Gustavo2026-03-302026-03-302025Piloto, Paulo A.G.; Ribeiro, Otavio; Ribeiro, Otavio (2025). Fire resistance of protected composite slab with a stiffened lower flange steel deck. In XV Congresso de Construção Metálica e Mista e I Congresso de Engenharia de Fachadas. p. 804-815. ISBN: 978-989-35292-3-2. DOI: 10.1002/cepa.70277978-989-35292-3-2http://hdl.handle.net/10198/36390This study developed a simplified method to evaluate the fire resistance of composite slabs with steel decking protected by a novel steel shield. A numerically validated model, incorporating experimental data, demonstrated that the steel shield increases insulation failure time by approximately 25% (criterion I) and significantly reduces temperatures in critical zones. New empirical coefficients (bᵢ, cᵢ) were calibrated for use with the EN 1994-1- 2 simplified method, enabling accurate prediction of the thermal and structural behaviour of this system. Mineral wool insulation provided even superior performance. The research offers a practical design tool for engineering more efficient and fire-safe composite slabs.engconference paper10.1002/cepa.70277