Steel structure fireproof coating is divided into which categories

1. Fireproof coating construction method

A. Scraping method B. Roller coating method C. Brushing method D. Air compressor spraying method E. Airless spraying method

1, the first construction method is the most common scraping method: often used such as fibreglass scraper, horn scraper, plastic scraper, hard rubber sheet and other metal or non-metallic hand scraping tools, will be the surface of the object a variety of thick slurry fireproofing coating or crevices and other excess part of the scraping off.

2, the second construction method is roller coating method: roller coating method is generally applied to the wall construction, in the roller on the surface of the paste paint, and then rolling back and forth on the wall surface.

3, the third construction method is brush coating method: brush coating method is not only applicable to wall construction, any other shape of the surface of the object can work, the vast majority of fireproofing coatings can be constructed in this way.

4, the fourth construction method is the air compressor spraying method: the use of air compressor pressurisation with a spray gun will be sprayed to the surface of the object after the atomisation of the paint, the coating quality after spraying is uniform, the production efficiency is very high. 5, the fourth construction method is the airless spraying: the use of plunger pumps, diaphragm pumps and other forms of pressurised pumps will be pressurised with a liquid paint, and then through the high-pressure hose to the airless spray gun, and finally in the airless nozzle to release the hydraulic pressure, instantaneous atomisation, and then the fire protection coating can be used in this way. Hydraulic pressure, instantaneous atomisation is sprayed onto the surface of the coated object to form a coating layer.

Steel structure is a structure made up of steel materials and is one of the main types of building structures. The structure is mainly composed of beams, steel columns, steel trusses and other components made of steel profiles and steel plates, etc., and adopts rust removal and antirust processes such as silanisation, pure manganese phosphating, washing and drying, and galvanisation. Welds, bolts or rivets are usually used to connect the components or parts. Because of its light self-weight and easy construction, it is widely used in large-scale factories, arenas, super-high-rise and other fields.

(1) It can be divided into solvent-based steel structure fireproof coating and water-based steel structure fireproof coating according to the type of binder. Solvent-based steel structure fireproof coating can be divided into solvent-based steel structure fireproof coating with low benzene content and solvent-based steel structure fireproof coating with high benzene content.

(2) According to the place of use, it can be divided into: indoor (N) steel structure fireproof coating: used on the surface of steel structure of indoor or hidden projects of buildings; outdoor (W) steel structure fireproof coating: used on the surface of steel structure of outdoor or open-air projects of buildings.

(3) According to the thickness of use, it can be divided into: ultra-thin type (CB) steel structure fireproof coating: coating thickness ≤3mm; thin type (B) steel structure fireproof coating: coating thickness of 3mm-7mm; thick type (H) steel structure fireproof coating: layer thickness of 8-50mm.

Extended Information

With the development of China's urban scale, the application of steel structure in China's construction industry has a very broad prospect. However, since steel structure itself is non-combustible, the issue of fireproof and heat insulation protection of steel structure was once neglected. According to domestic and international data reports and tests and statistics from relevant organisations, the fire resistance of steel buildings is poorer than that of masonry and reinforced concrete structures.

The mechanical strength of steel decreases with the increase of temperature, and its strength decreases to 40%-50% at about 500℃, and the mechanical properties of steel, such as yield point, compressive strength, modulus of elasticity, and load capacity, etc., decrease rapidly, and soon lose the ability to support the building, leading to the collapse of the building. Therefore, it is imperative to protect the steel structure.

Steel structure fireproof coating is brushed or sprayed on the surface of steel structure, which plays the role of fireproofing and heat insulation, prevents the steel from rapidly heating up and decreasing its strength in fire, and avoids the steel structure from losing its supporting ability and leading to the collapse of the building.

As early as in the 1970s, foreign research and application of steel structure fireproof coating has started active work and made good achievements, and is still in the ascendant.

In the early 80s, foreign steel structure fireproof coating entered the Chinese market and was applied in the project. From the early 80's, China also began to develop steel structure fireproof coating, so far there are many good varieties widely used in various industries.

2.Thin-type steel structure fireproof coating

Thin type steel structure fireproof coating refers to the steel structure fireproof coating with coating thickness greater than 3mm, less than or equal to 7mm, with certain decorative effect, expansion and thickening at high temperature, and fire resistance limit within 2h. This kind of steel structure fireproof coating is generally made of suitable water-based polymers as the base material, and then matched with fire retardant composite system, fire additives, fire-resistant fibres, etc., and its fireproofing principle is the same as that of ultra-thin type. For this kind of fireproof coating, the selected water-based polymer must have good adhesion, durability and water resistance to the steel substrate. Its decorative property is better than thick fireproof coating, inferior to ultra-thin steel structure fireproof coating, and the general fire resistance limit is within 2h. Therefore, it is commonly used in the steel structure fire protection project with fire resistance limit less than 2h, and often adopts spraying construction. It occupies a large proportion in a period of time, but with the appearance of ultra-thin steel structure fireproof coating, its market share is gradually replaced.

3.Thick steel structure fireproof coating

Thick steel structure fireproof coating refers to the steel structure fireproof coating with coating thickness greater than 7mm, less than or equal to 45mm, granular surface, low density, low thermal conductivity, and fire-resistant limit of more than 2h. As the components of thick fireproof coating are mostly inorganic materials, its fireproof performance is stable and the long-term use is better, but the particles of its coating components are larger and the appearance of the coating is uneven, which affects the overall aesthetics of the building, so it is mostly used for structural concealment projects. This type of fireproof coating in the fire using the material granular surface, less density, low thermal conductivity or the heat absorption of the material in the coating, delaying the temperature rise of the steel to protect the steel. This type of fireproof coating is a suitable inorganic binder (such as water glass, silica sol, aluminium phosphate, refractory cement, etc.), and then with inorganic lightweight adiabatic aggregate materials (such as expanded perlite, expanded vermiculite, sea hugger, bleached beads, fly ash, etc.), fire additives, chemicals and reinforcing materials (such as aluminium silicate fibres, rock wool, ceramic fibres, glass fibres, etc.) and fillers, etc., mixed and prepared, with a relatively costly The advantages of low cost. The construction often adopts spraying, which is suitable for indoor and outdoor hidden steel structure with fire resistance limit above 2h, high-rise all-steel structure and multi-storey plant steel structure. For example, the fire resistance limit of columns of high-rise civil buildings and columns supporting multi-storey in general industrial and civil buildings should reach 3h, and need to be protected by the thick fireproof coating.Ultra-thin steel structure fireproof coating refers to the steel structure fireproof coating with coating thickness of 3mm (including 3mm) or less, with good decorative effect, expanding and foaming at high temperature, and with fire-resistance limit of 2h or less. This kind of steel structure fireproof coating is generally a solvent-based system, with superior adhesive strength, good weather resistance and water resistance, good levelling, good decorative features; when under fire, it slowly expands and foams to form a dense and hard fireproof heat insulation layer, which has a strong fire resistance to impact, slows down the temperature rise of the steel, and protects the steel components effectively. The construction of ultra-thin intumescent steel structure fireproof coating can be sprayed, brushed or roller coated, generally used in the fire-resistant limit requirements within 2h on the building steel structure. There are new varieties of ultra-thin steel structure fireproof coatings with fire resistance performance reaching or exceeding 2h, which are mainly based on the special structure of polymethacrylate or epoxy resin and amino resin, chlorinated paraffin wax, etc. as the base material binder, with high polymerisation of polyphosphoric acid ammonium salt, dipentaerythritol, melamine and so on as the fireproofing and flame-retardant system, adding titanium dioxide, wollastonite and other inorganic refractory materials to 200# solvent oil as the solvent composite. Solvent oil is used as the solvent. All kinds of light steel structure, net frame and so on mostly use this type of fireproof coating for fire protection. Due to the ultra-thin coating of this type of fireproof coating, the use of thicker and thinner steel structure fireproof coating is greatly reduced, thus reducing the total cost of the project, but also making the steel structure to get effective fire protection, and the fireproof effect is very good.