High-rise building steel structure and the performance of the refractory fire retardant coating, discussion
1, steel structure fireproofing coatings
Steel structure as a form of high-rise building structure, with its high strength, light quality, and has good extensibility, shock resistance and the characteristics of short construction period, is widely used in the construction industry, especially in the high and large span buildings shows strong vitality. By the end of 1990, the world's 200 m high above 100 super-tall building steel structure accounted for 79%. Since China's reform and opening up, with the strengthening of international technical exchanges and cooperation, the steel structure application technology has been booming in China, the tall and super-tall building to grow rapidly. According to the statistical data in 1995, built in 100 in our country of steel structure in high-rise building is occupied 37%, mostly built in recent years. Along with the development of the urban scale, the application of steel structure construction in our country has a very broad prospect. Noncombustible itself but because steel structure, steel structure fire insulation protection had been overlooked. According to relevant materials at home and abroad and relevant institutions of test and statistics show that the fireproof property of the steel structure of the masonry structure and reinforced concrete structure. Steel mechanical strength decreases with the rise of temperature, and at about 5000 ℃, its strength decreased to 40% ~ 40%, the mechanical properties of steel, such as the yield point, compressive strength, elastic modulus and loading capacity are falling fast, soon lost support ability, lead to building collapse. Therefore, it is imperative to protection of steel structure. Steel structure fire retardant paint brush or spray on the surface of steel structure, fire protection and heat insulation effect, prevent rapid warming in the fire and the intensity of lower steel, avoid steel structures caused by losing the ability to support the building collapsed. In the early 1970 s, foreign research and application of fire retardant coating for steel structure is carried out positive work and achieved good achievements, is still thriving. In the early 80 s steel structure fire retardant coatings abroad to enter the Chinese market, in engineering applications. From the early 80 s, our country also started developing steel structure fire retardant coatings, it has been a lot of good varieties are widely used in all walks of life.
2, the thick coated steel structure fire retardant coating
Thick coated steel structure fire retardant coating is refers to the coating thickness in 8 ~ 50 mm coating, the fire resistance of this kind of fire retardant coatings can reach 0.5 ~ 3 h. Coating in the fire is not inflation, depending on the materials noncombustible or coating material, low thermal conductivity of heat resistance, delay the temperature of steel, steel protection. This kind of steel structure fire retardant coatings using appropriate binder, combined with inorganic lightweight materials, reinforced material. Compared with other types of steel structure fire-retardant coating, in addition to some of the advantages of fire retardant coating with water soluble, due to it from the most basic material to the additives are inorganic substances, so the cost is low. This kind of steel structure construction, generally with spray, fire retardant coating application in refractory limit for more than 2 h interior steel structure. But this kind of product because of the thick coating, adornment sex is relatively poor appearance.
