download: 866-5795-3-PBenglish.pdf .In many situations, the Brazilian Legislation does not require verification of roof structures in a fire, since its failure will not endanger the stability of the structure. In fire, the steel roof of an industrial building deforms by heating in geometry similar to a catenary, resulting in horizontal forces in the upper extremities of the columns. Thus, even roofs that do not constitute a frame with the columns may lead them to collapse, therefore, should be protected against fire. Due to the small dimensions of the structural elements of the roof, fire coating is uneconomical. So there is a problem in the design practice. This paper presents a procedure based on British literature, which considers the horizontal load on the columns. This horizontal load must be supported by the columns and the foundations. The aim of this paper is to detail this procedure, adapt it to Brazilian standards and apply it to a case study.Leia Mais
Steel elements behave differently in fire case when isolated or embedded in building walls. The wallson one hand have a favorable effect protecting the elements from the excessive heating resulting fromthe fire and on the other hand they have a detrimental effect due to the thermal gradients originated inthe elements cross-section. The simplified calculation methods proposed in EN 1993-1-2 for fire designdo not take into account the case of steel elements embedded in walls, stipulating only a formulationfor the assessment of the resistance for uniform temperature distribution. This paper presents a proposalof a new simplified calculation method to evaluate the temperature of steel columns embedded in walls.The method is based on numerical simulations and fire resistance tests. Steel columns totally or partiallyembedded in walls, with the web perpendicular or parallel to the wall surface, were tested.In the study it was also observed that thicker walls or H steel columns with the web perpendicular tothe wall surface provide greater thermal gradients in the cross-sections.