Fire protection of steel structure

The fire protection of steel structure usually has the following ways:

1. Fireproof coating for steel structure

Fireproof coating for steel structure is a kind of coating applied on the surface of steel structure of buildings and structures, which can form a fire-resistant and heat insulation protective layer to improve the fire resistance limit of steel structure. It can be divided into thick type, thin type and ultra-thin type. Thick coating is granular, the coating thickness is usually more than 8 mm, the construction method is spraying, high temperature depends on the thickness of the coating itself and low thermal conductivity to play the role of heat insulation of steel components. The thin and ultra-thin coatings are thin and have a certain decorative effect. The construction method can be sprayed and brushed. The coating expands and thickens at high temperature to protect steel members. The utility model has the advantages of light weight, simple construction, and is suitable for concealed structures, exposed steel beams, diagonal braces and other steel members.

2. Brick method of pouring concrete

When the cast-in-place concrete is used as the outer covering, it can be cast in-situ on the steel structure, or the spraying method (spraying process) can be used. In order to limit the shrinkage crack and ensure the strength of the shell, the steel wire mesh or steel bar can be used to strengthen the external layer of cast-in-place concrete. The surface of steel structure can also be coated with mortar in the construction site to form a protective layer. Mortar can be lime, cement or gypsum mortar, or mixed with perlite or asbestos. The outer layer can also be prefabricated slabs made of perlite, asbestos, gypsum or asbestos cement and light concrete, which are fixed on the steel structure with adhesives and nails or bolts. This method has the advantages of high strength, impact resistance and large space occupation, which is suitable for the fire protection of steel columns with easy collision and unprotected panel.

3. Water filling method

Filling water in hollow steel members is the most effective way to resist fire, which can keep the steel structure at a low temperature in case of fire. The water circulates in the structural members, and the heated water can be recycled by cooling, or the cold water can be introduced from the water pipe to replace the heated water. This method is widely used in steel column protection abroad. This method has low cost, high requirements for anti leakage and anti-corrosion of hollow steel members, and is only suitable for the protection of hollow steel members.