Selecting Issues
Firstly, do not use paint with technical performance suitable only for indoor use outdoors.
Outdoor environments are significantly worse than indoor ones. Outdoor fire-retardant coatings should be chosen for their water resistance, frost-thaw resistance, aging resistance, and high strength, as outdoor fire-retardant coatings must withstand wind, sun, rain, and freezing temperatures.
Secondly, avoid using decorative fire-retardant coatings to protect steel structures. These coatings typically do not provide sufficient insulation to significantly enhance the fire resistance of steel.
To overcome the fire resistance limitations of steel structural materials in practical applications, fire treatment is essential. The aim is to enhance the fire resistance of steel structures to the maximum limit specified by design standards. Measures to prevent the rapid temperature rise and deformation of steel structures during fires are diverse. The key is to adopt different methods based on varying situations, such as using insulating and refractory materials to block direct flame burning of the steel structure by transparent screens, slowing down the rate of heat transfer, and delaying the time when the steel structure's temperature increases and strength weakens. However, regardless of the method employed, the principle remains consistent. Below, we introduce several fire protection measures for different steel structures.
Adding an external layer to the steel structure can be cast in place or applied by spraying. The cast-in-place concrete layer is typically reinforced with wire mesh or rebars to restrict shrinkage cracks and ensure the shell's strength. The spraying method involves applying a sand pump to the steel surface at the construction site to form a protective layer, which can be made of lime cement or gypsum mortar, and can also include perlite or asbestos. Additionally, the external layer can be prefabricated into panels made of perlite, asbestos, gypsum, or asbestos cement, light concrete, and fixed to the steel structure using adhesives, nails, or bolts.