Does anyone know about the fire resistance period of thin fireproof coatings?
Outdoor thin steelwork fireproof coatings have a fire resistance of 2.0 hours, the thickness of coatings is between 4.5 to 5 mm, the standard amount is 5.5 to 6kg per square meter. Specific situations vary according to the thickness data provided by manufacturers . The fireproof coatings are applicable for the surface of combustible substrates, which can reduce the flammability of the surface being painted, and block the rapid spread of fire. They can be used to improve the fire resistance of the materials being painted. The fireproof coatings are coated on the substrate surfaces. They are also rustproof, waterproof, wearproof, heatproof and anticorrosive apart from flame retardant. They have good tenacity, stainability, adhesiveness, glossiness and fast-drying nature.
The thin fireproof coatings will be expanded when exposing to open fire, and produce the inert gas to extinguish fire, but they will do harm to people, and the coatings are not stable, and the weather resistance and service life of which are short. According to the state regulations, the thin fireproof coatings have the highest fire resistance of only 2.5 hours, while the thick steelwork fireproof coatings have a fire resistance of 3.0 hours or more.
The columns are 2.5 to 3.0 hours, beams are 2.5 hours, C-shaped steels are 0.5 hours. The thin steelwork fireproof coatings are primarily water-soluble, which will be expanded and foamed when exposing to the fire. Thus the fire-resistant insulation layer formed through expansion and foaming will delay the temperature increase of the steel and protect of steel components. The thin fireproof coatings are made of adhesives, catalysts, carburizers, foamers, fillers, fibers and modifiers. The required emulsion polymers must have good adhesion, durability, and water-resistance to the steel substrates. The coating has a strong adhesion and good flexibility, is light and thin, as well as highly resistant to vibration. It is especially applicable for indoor bareness steel structure, light layer steel structure, and steel structure with decoration demands whose fire resistance requirement is within 1.5-2.5 hours.
