Steel structure is a structure composed of steel materials and is one of the main building structure types. The structure is mainly composed of steel beams, steel columns, steel trusses and other components made of section steel and steel plates, and adopts silanization, pure manganese phosphating, washing and drying, galvanizing and other rust prevention processes. The components or components are usually connected by welds, bolts or rivets. Because of its light weight and simple construction, it is widely used in large factories, venues, super high-rise buildings, Bridges and other fields. The steel structure is easy to rust, the general steel structure to remove rust, galvanized or paint, and regular maintenance.

peculiarity

1. high material strength, light weight

Steel has a high strength and elastic modulus. Compared with concrete and wood, the ratio of density to yield strength is relatively low. Therefore, in the case of bearing the same external force, the component section of the steel structure is small, the weight is light, and it is easy to transport and install. This makes steel structures very suitable for buildings with large spans, high heights and heavy loads.

2. the steel toughness is good, strong plasticity, uniform material, high structural reliability

The steel structure can withstand the impact and dynamic load, and has good seismic performance. The internal structure of the steel is uniform and close to isotropic uniform body. The actual performance of the steel structure agrees with the calculation theory. Therefore, the steel structure has a high reliability.

3. steel structure manufacturing and installation of high degree of mechanization

Steel structural components can be manufactured in factories and assembled on site. The factory mechanized manufacturing of steel structure components has high precision, high production efficiency, fast site assembly speed and short construction period. Steel structure is the most industrialized structure.

4. the steel structure sealing performance is good

Because the welded structure can be completely sealed, it can be made of high pressure vessels with good air tightness and water tightness, large oil pools and pressure pipelines.

5. steel structure heat resistance is not fire resistant

When the temperature is below 150℃, the steel properties change little. Therefore, the steel structure is suitable for hot workshops. However, when the surface of the structure is subjected to thermal radiation of about 150 ° C, it is necessary to use heat insulation panels for protection. When the temperature is between 300℃ and 400℃, the strength and elastic modulus of steel will decrease significantly. When the temperature is about 600 ° C, the strength of the steel tends to zero. In buildings with special fire protection needs, the steel structure must be protected by refractory materials to improve the fire resistance grade.

6. Poor corrosion resistance of steel structure

Especially in the environment of wet and corrosive media, steel structures are easy to rust. Typically, steel structures need to be derusted, galvanized or painted and require regular maintenance. For the offshore platform structure in seawater, it is necessary to adopt special measures such as "zinc block anode protection" for anti-corrosion treatment.

7. low carbon, energy saving, green environmental protection, reusable

When steel structure buildings are dismantled, almost no construction waste is generated, and steel can be recycled.

Development course

Although China has excellent achievements in iron structure, it has long remained at the level of iron buildings. Until the end of the 19th century, China began to use modern steel structure. After the establishment of New China, the application of steel structure has been greatly developed, both in quantity and quality are far beyond the past. The floor of the light steel structure consists of cold-formed thin-wall steel frame or composite beam, floor OSB structural plate, support and connecting parts. Materials used include oriented particleboard, cement fiber board and plywood. On these lightweight floors, a load of 316 to 365 kilograms per square meter can be borne.

The number of steel structure buildings indicates the economic strength and economic development of a country or region. After entering the year 2000, with the significant growth of China's national economy and the significant enhancement of national strength, steel production has become one of the world's major powers. In the field of construction, it is proposed to "actively and reasonably use steel", and from now on, it has got rid of the restriction of "restricting the use of steel". Steel structure buildings are gradually increasing in economically developed areas. Especially around 2008, driven by the Olympic Games, there was a boom in steel structure construction. Strong market demand has promoted the rapid development of steel structure buildings, and many steel structure venues, airports, stations and high-rise buildings have been built. Some of these steel structure buildings have world-class levels in terms of production and installation technology, such as the Olympic National Stadium and other buildings.

After the Olympic Games, steel structure buildings have been popularized and sustained development. Steel structure is widely used in construction, railway, bridge and residential fields. There are tens of thousands of steel structure enterprises of various sizes, and the world's advanced steel structure processing equipment is basically complete, such as multi-dimensional drilling machines, multi-dimensional steel pipe intersecting line cutting machines and automatic welding machines for corrugated plates. At present, the processing and production level of hundreds of steel structure enterprises has the world's advanced level, such as steel structure production and first-class enterprises. In recent years, China's steel production has reached more than 600 million tons per year, and steel varieties can fully meet construction needs. Steel structure design specifications, steel structure material standards, steel structure engineering construction quality acceptance specifications and various professional specifications and enterprise construction methods are basically complete