Materiais de proteção térmica para sistemas construtivos de baixo custo estruturados em aço

Abstract

Nowadays the fire security has been expanding as multidisciplinary science, involving many fields of engineering, demanding an important integration of different areas and efforts, mainly about building materials. The development of low cost constructive system structured by steel, has been becoming a common practice and a necessity in attendance to poorly paid public. Despite the characteristic of these buildings they must obey perfectly the fire security rules. In this work, it was conducted the thermal analysis of beams in box shape, typical of these buildings, with beams made in cold and USI SAC 300 steel, submitted under high temperature using natural and standard fire curves. Parameters based on the preservations indices of flow limits and elasticity modulus of steel had been established. Thus was concluded that those materials wich kept conditions to preserve the resistance of steel for more time showed a better performance. Two softwares was used, the Smartfire and Thersys, as tools for simulate fires in compartments, and to do the analysis of temperature in the beams and also the performance of incorporated materials for thermal protection in structural elements. The analysis of results presented the performance of some materials used as passive protection. The first tests had been carried out in beams without protection and later with protection using projected fiber, vermiculite concrete, rockwool, ceramic blanket and gypsum plate. Concluded the experiences we verified that the beams protected with projected fiber and gypsum plates did not presented reduction of the flow limits and modulus of elasticity, for more than a satisfactory time.