Steel structure has the following advantages and disadvantages:

　　①High strength and light weight. The strength of steel is high and the modulus of elasticity is also high, so the steel structural members are small and light. There are steels of various strength grades. Even the steels with lower strengths generally have a lower density-to-strength ratio than those of concrete and wood. Therefore, under the same stress conditions, the steel structure has a small self-weight and can be made into a larger span. Structure. Because the rod is small, it occupies less space, and is also convenient for transportation and installation.

　　②The material is uniform and the reliability is high. The steel structure is uniform, close to the isotropic homogeneous body. The steel is produced by steel mills with strict control and relatively stable quality. The actual working performance of the steel structure is more in line with the theoretical calculation results currently used, so the reliability of the steel structure is high.

　　③Good plasticity and toughness. The steel structure has the same tensile and compressive strength, good plasticity and toughness, is suitable for bearing impact and dynamic loads, and has good seismic performance.

　　④Easy for mechanized manufacturing. The steel structure is made of rolled profiles and steel plates in the factory, which is convenient for mechanized manufacturing. Production efficiency "high production efficiency, fast speed, high precision of finished products, and easy quality assurance. It is a structure with the highest degree of industrialization in engineering structures.

　　⑤Easy installation and short construction period. The steel structure is easy to install and the construction period is short, and the economic benefits of the investment can be exerted as soon as possible.

　　⑥Good sealing performance. The tightness of the steel structure is good, and it is easy to make a watertight and airtight atmospheric and high-pressure container structure and large-diameter pipeline.

　　⑦Good heat resistance. When the surface temperature of the structure is within 200 °C, the strength of the steel changes very little, so the steel structure is suitable for hot cars. However, when the surface of the structure is exposed to radiant heat up to 150°C for a long time, a heat shield should be used to protect it.

　　⑧ Poor fire resistance. The steel structure has poor fire resistance. After the surface temperature of the steel reaches 300 to 400 °C, its strength and elastic modulus decrease significantly, and it almost drops to zero at 600 °C. When the fire resistance requirements are high, protective measures need to be taken, such as clad concrete or other fireproof boards on the outside of the steel structure, or spray a layer of fireproof paint containing thermal insulation materials and chemical additives on the surface of the components to improve the fire resistance level.

　　⑨ Poor corrosion resistance. The corrosion resistance of steel structure is poor, especially in the environment with corrosive medium in the wet phase, it is easy to rust, and regular maintenance is required, which increases the maintenance cost.