Paint knowledge | steel structure fireproof coating thickness selection standard

Core tip: the current standard gb14907-2002 fire retardant coatings for steel structures has made clear provisions on the classification and quality requirements of fire retardant coatings for steel structures The national fire protection product quality supervision and inspection institution has carried out type inspection of ultra-thin, thin and thick steel structure fire retardant coating products with three standard coating thicknesses of 2 ± 0.2mm, 5 ± 0.2mm and 25 ± 2mm respectively The coating thickness and fire resistance test time of the inspection results are taken as the product name and specification certificate content of the product type approval certificate 1、 Fire retardant coating for steel structure can be divided into: a fire retardant for indoor steel structure Paint agent, top 10 Chinese wall paint brands Recommended introduction: interior wall paint and exterior wall paint can achieve beautiful, clean and pleasant effects, but the effects in different environments are different, so the color of the paint will be different There are ten brands of Chinese paint, ten brands of global paint, ten brands of Chinese wall paint, and ten brands of Chinese paint, Famous trademark of Chinese paint and coating In private rooms, most of us choose according to our own personality, personal hobbies and living habits The younger generation will choose the interior wall paint with rich colors and bright colors, while the older ones will have some working experience Home of coatings: the current standard gb14907-2002 fire retardant coatings for steel structures has made clear provisions on the classification and quality requirements of fire retardant coatings for steel structures The national fire protection product quality supervision and inspection institution has carried out type inspection of ultra-thin, thin and thick steel structure fire retardant coating products with three standard coating thicknesses of 2 ± 0.2mm, 5 ± 0.2mm and 25 ± 2mm respectively The coating thickness and fire resistance test time of the inspection results are taken as the product name and specification certificate content of the product type approval certificate 1、 Fire retardant coating for steel structure can be divided into: a fire retardant coating for indoor steel structure: the surface of steel structure used for indoor or concealed works of buildings; B fire retardant coating for outdoor steel structure: the surface of steel structure used for outdoor or open works of buildings Fire retardant coating for steel structure can be divided into: a ultra thin fire retardant coating for steel structure: coating thickness is less than or equal to 3mm; B thin fire retardant coating for steel structure: coating thickness is greater than 3mm and less than or equal to 7mm; C thick fire retardant coating for steel structure: coating thickness is greater than 7mm and less than or equal to 45mm 2、 Coating thickness and fire resistance The quality of fireproof coating for steel structure is affected by many factors Different manufacturers have different product quality due to raw materials, production process, formula and other factors The same manufacturer, the same type of different batches of products, there are differences in product quality As shown in Table 3 Table 3 Fire endurance test data of fire retardant coating for steel structure of a manufacturer: coating name, product batch number, coating thickness mm fire endurance min ultra thin fire retardant coating for steel structure 82 h-720.0 > 120 h-817.898 It can be seen from table 3 that the coating thickness of different batches of fire retardant coatings of the same type has little correlation with the fire resistance limit In theory, for the same batch of fire retardant coating, the function between coating thickness and fire resistance limit should be relevant within a certain range However, because the fire resistance limit and coating thickness of fire retardant coating for steel structure are measured under laboratory conditions, which are quite different from the technical conditions of construction site, there is no technical condition for conversion of coating thickness in construction In order to verify, we chose the same batch of thick steel structure fire retardant coating to test the fire resistance limit according to different spraying thickness The results are shown in Table 4 It can be seen from this that the fire endurance increases with the increase of coating thickness However, due to the limited funding of this topic, more tests cannot be carried out, so the correlation between coating thickness and fire endurance cannot be determined Table 4 Fire endurance test number of a thick steel structure fire retardant coating: coating thickness mm fire endurance minht-115115, ht-225205, ht-330210 From the above analysis, it is believed that the fire resistance limit of fire-resistant coating for steel structure is the only corresponding to the coating thickness during testing, and the actual spraying thickness during construction cannot be converted, which must be determined according to the testing data of fire resistance limit During the quality inspection at the construction site, whether the coating thickness meets the design requirements shall be based on the test data of the batch's fire resistance limit 3、 The relationship between the thickness of fireproof coating and the fire resistance limit of steel structure is as follows according to the standard of gb9978 building temperature rise curve 1.5h 2.0h 2.5h 3.0h 11mm 15mm 19mm 23mm according to BSEN 1363-2:1999 hydrocarbon fire heating curve has the following relationship 1.5h 2.0h 2.5h 15mm 24mm 32mm 4 Calculation method of application thickness of fire retardant coating for steel structure When designing the fire protection coating and spraying construction, according to the thickness of the protective layer of a certain fire resistance limit obtained from the standard test, the thickness of the protective layer of the same fire protection coating required for different specifications of steel members to reach the same fire resistance limit can be determined by referring to the following empirical formula: T1 -- thickness of the fire protection coating to be sprayed mm; T2 -- thickness of the coating in the standard test mm; W1 -- weight of steel beam to be sprayed kg / M; W2 -- weight of steel beam in standard test kg / M; D1 -- perimeter of fire coating contact surface of steel beam to be sprayed mm; D2 -- perimeter of fire coating contact surface of steel beam in standard test mm; K -- coefficient For the steel beam, k = 1; for the thickness of the protective layer of the steel column of the corresponding floor, the coefficient K should be multiplied, and K = 1.25 The limiting conditions of the formula are: w / D ≥ 22, t ≥ 9mm, fire resistance limit t ≥ 1H Home of coatings is specialized in coatings, diatom mud, paint coating, coating technology, fire retardant coating news and coating, diatom mud, paint coating, coating technology, fire retardant coating decoration knowledge and decoration renderings,