Investigation of load deformation curves ofsteel T joints exposed to high temperatures

Building fires cause worldwide casualties and serious economic losses.Steel structure elements, which offer engineers the opportunity to design multi-storey and light structures with advantages such as being dismantled when necessary, high strength, low structure weight per square meter and ductility, can turn into a disaster in these structures if fire safety is not provided. Steel is a material with high thermal conductivity. It starts to melt at high temperatures. According to Eurocode design guidelines, it loses 50% of steel strength at 550-600 degrees. For this reason, fire safety should be considered as an indispensable part of structural integrity, especially at the design stage, and the fire safety strategies required for the building should be determined. In addition, since steel structures are not monolithic and rigid, such as reinforced concrete structures, the building elements are partially protected in steel structures exposed to fire or high temperature and in order to take measures for possible structural damage by delaying the effects of high temperature on steel structure elements and to ensure life safety. It is a fire safety method to cover the elements with materials that can create a thermal barrier effect. In this study, the load deformation relations of the T joints, which are the most common form of informatics of bearing elements in steel structures, are investigated after exposure to high temperatures that will occur in cases such as fire. The effects of paint thickness on the load deformation curves of the joints were investigated by painting T compositions in different thicknesses with water-based paint, which was developed for high temperature protection of steel construction elements, which can create a thermal barrier effect against its widespread effect, and provides fire insulation by expanding. Keywords: Steel structure, thermal expansion, fire security, insulation in steel structures, unshielded steel, high temperature effect, bolted connections. column and beam connections, thermal conductivity