The structure mainly made of steel is one of the main types of building structures. The characteristics of steel are high strength, light weight, good overall rigidity and strong deformation ability, so it is especially suitable for the construction of large-span, super-high and super-heavy buildings; the material has good homogeneity and isotropy, and is an ideal elastomer , which is most in line with the basic assumptions of general engineering mechanics; the material has good plasticity and toughness, can have large deformation, and can withstand
dynamic loads well; the construction period is short; its degree of industrialization is high, and it can be used for specialized production with a high degree of mechanization. In the future, high-strength steel should be studied for steel structures to greatly improve its yield point strength; in addition, new types of steel, such as H-beam (also known as wide-flange steel), T-shaped steel, and profiled steel, should be rolled to adapt to large-span structures. and super high-rise buildings.
1. High material strength and light weight The steel has high strength and high elastic modulus. Compared with concrete and wood, the ratio of its density to yield strength is relatively low, so under the same stress conditions, the steel structure has a small cross-section and light weight, which is convenient for transportation and installation, and is suitable for large spans, high heights, and heavy loads Structure.
2. The steel has good toughness, good plasticity, uniform material and high structural reliability. It is suitable for bearing impact and dynamic load, and has good seismic performance. The internal structure of steel is uniform, close to isotropic homogeneous body. The actual working performance of the steel structure is more in line with the calculation theory. Therefore, the reliability of the steel structure is high.
3. High degree of mechanization of steel structure manufacturing and installation Steel structure components are easy to manufacture in factories and assemble on site. The factory mechanized manufacturing of steel structural components has high precision, high production efficiency, fast assembly speed on site, and short construction period. Steel structure is the most industrialized structure.
4. The steel structure has good sealing performance. Because the welded structure can be completely sealed, it can be made into high-pressure containers, large oil pools, pressure pipes, etc. with good air tightness and water tightness.
5. The steel structure is heat-resistant and not refractory. When the temperature is below 150 °C, the properties of the steel change very little. Therefore, the steel structure is suitable for hot workshops, but when the surface of the structure is exposed to heat radiation of about 150 ° C, it should be protected by a heat insulation board. When the temperature is between 300°C and 400°C, the strength and elastic modulus of the steel decrease significantly. When the temperature is around 600°C, the strength of the steel tends to zero. In buildings with special fire protection requirements, the steel structure must be protected by refractory materials to improve the fire resistance rating.
6. The corrosion resistance of steel structure is poor, especially in the environment of wet and corrosive medium, it is easy to rust. Generally, the steel structure needs to be derusted, galvanized or painted, and it needs to be maintained regularly. For the structure of the offshore platform in seawater, special measures such as "zinc block anode protection" should be adopted to prevent corrosion.
7. Low-carbon, energy-saving, green and environmentally friendly, and reusable The demolition of steel structure buildings hardly produces construction waste, and the steel can be recycled and reused.