2025-03-19    225

The characteristics of steel structures include excellent heat resistance but relatively poor fire resistance. Tests indicate that as temperature rises from ambient to 150°C, steel retains its strength and plasticity. However, at 600°C, its strength drastically decreases, dropping to zero and resulting in complete loss of load-bearing capacity. To enhance fire resistance, steel structures are often externally wrapped or coated with fireproof materials. For example, applying a 15mm-thick fire-resistant coating can extend the fire resistance limit of steel components to 1.5 hours.

Classification by Building Height and Layers:

1. Single-story:

• Industrial workshops (floor height ≥ 6–8m).

• Civil buildings (floor height 2.2–3m).

• Agricultural sheds (floor height ≥ 2.2m).

• A single-story building has only one floor, including:

2. Multi-story:

• Refers to buildings with 4–6 floors.

3. High-rise:

• Buildings with over 10 floors but a total height below 100 meters.

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4. Super high-rise:

• Buildings with over 40 floors and a total height exceeding 100 meters.

5. Structural Forms for High-rise and Super High-rise:

• Cross-shaped columns.

• Box columns.

• Primarily use steel-concrete composite structures, such as:

This classification helps in understanding design requirements, material selection, and safety standards based on building height and usage.