3.4 Building fire prevention technology

3.5 Building sound insulation technology

4. The characteristics of steel

4.1 Light weight steel structure

4.2 Higher reliability of steel work

4.3 Steel anti-vibration (earthquake), impact and good

4.4 Steel structure for a higher degree of industrialization

4.5 Steel can be assembled quickly and accurately

4.6 Large steel interior space

4.7 Likely to cause sealing structure

4.8 Steel corrosive

4.9 Poor fire-resistant steel

4.10 Recyclable steel

4.11 Steel shorter duration

5. Commonly used steel grades and performance of steel

5.1 Carbon structural steel: Q195, Q215, Q235, Q255, Q275, Q345,etc.

5.2 High-strength low-alloy structural steel

5.3 Quality carbon structural steel and alloy structural steel

5.4 Special purpose steel