Resistance of partially intumescent covered steel member in fire

In practice, there exist situations in which the fire protection is not covering the structural steel member uniformly. Such a situation may occur e.g. when connected members or other obstacles are present during the fire... [ view full abstract ]

In practice, there exist situations in which the fire protection is not covering the structural steel member uniformly. Such a situation may occur e.g. when connected members or other obstacles are present during the fire protection installation in site, or when the fire protection is damaged due to other reasons. This causes unsymmetric temperature field to the member cross-section during the fire complicating the prediction of the structural behavior of the member. In this paper, the moment resistance of an I-section steel member with intumescent coating is considered in case where one side of a flange is totally without fire protection. The finite element method taking into account the foaming process of the intumescent coating, is used for the definition of the temperature field of the member. The FEM model is validated with the existing literature test results for cases in which the fire protection is uniform around the cross section. After the validation, the FEM model is used to simulate the bending resistance of partially covered steel members. The resistance in the standard ISO fire is compared to a case where the fire protection is complete and to a case without any fire protection. Reductions of material properties of steel at elevated temperatures are carried out by following the standard Eurocode practice. Based on the results, the proposed method is suitable for the definition of the behavior of steel members in non-symmetric fires due to partial intumescent cover.