As the steel components themselves cannot reach the fire resistance limit required by the development of the specification, it is necessary to take some corresponding fire protection management measures for the steel components when building steel structure workshops. Fire prevention measures usually include fire-retardant coating methods, foam fire-retardant coating methods and outsourcing fire-retardant coating methods.
1. Fireproof coating method
The fire-retardant coating method is to spray fire-retardant coatings on the steel structure of the steel structure workshop to increase the limit of its refractory materials. At present, my country's steel structure fireproof coatings are mainly divided into thin coatings and thick coatings. The thickness of the thin coating is generally 7 mm or less. In the event of a fire, it can absorb heat and expand and foam to form a foamed carbonized insulation layer to prevent heat transfer to the steel carbon, delay the temperature rise of the steel structure, and play a role in fire protection.
The main advantages are:
The coating is thin, the load on the steel structure is light, and the decoration is good. It is easier to apply the surface of the steel structure factory building with a small area and more complex structure than the thick type; the thickness of the thick type coating material is 8-50mm, and the coating is heated It does not foam, and relies on its lower thermal conductivity to delay the increase in the design temperature of the steel structure, which can play a role in fire safety protection. The two have different performance characteristics and are used in different occasions. However, no matter which kind of product should pass the national inspection agency, it can be used.
2. Foaming fireproof paint method
Foaming fire-retardant paint is a kind of flame-retardant paint made of a variety of different materials such as film formers, flame retardants, and foaming agents. Compared with general paints, fire-resistant coatings are basically the same in physical properties. The difference is that after drying, the paint film itself is not easy to burn. When a fire occurs, it can delay the flame from burning on the combustibles of the paint, and has certain fire resistance. According to the test: the general paint and fire-resistant paint are painted on the wooden boards separately. After drying, the same flame is baked. The general-painted wooden boards burn together with the paint in less than 2 minutes; while the non-intumescent fire-retardant paints only After 2 minutes, the smoldering phenomenon will continue for 30 seconds, and it will be extinguished immediately; the intumescent fire retardant paint coated wood, even if it is baked for 15 minutes, even the smoldering phenomenon does not appear. From this we can see that using fire-resistant paint on the surface of an object, once a major fire occurs in a building, it can indeed prevent the fire from spreading within the specified time and protect the surface of the object, thereby gaining valuable time for extinguishing the fire.
3. Outsourcing fire protection
The method of outsourcing the fireproof layer of steel structure workshop is to add an outer layer to the steel, and the casting molding can also be applied by spraying. The concrete cladding of the cast-in-place structure is usually reinforced with steel wire mesh or steel bars to limit the cracks caused by shrinkage and ensure the strength of the product shell. The spraying method can spray lime cement or gypsum mortar on the surface of the steel structure to form a protective layer, or it can be mixed with perlite or asbestos. The outer layer can be perlite, asbestos, cement or asbestos gypsum. Lightweight concrete is made into a prefabricated board, which is fixed on the steel structure with adhesives, nails, and bolts.