How does passive fire protection differ for steel versus concrete structural elements?

• A. Steel requires insulation or protective coatings; concrete has inherent fire resistance but may require detailing to prevent spalling and ensure protection.
• B. Steel has inherent fire resistance but concrete does not.
• C. Both materials require identical protective coatings.
• D. Concrete requires more protection than steel in all cases.

Answer: (A)

Passive fire protection design focuses on how materials behave when exposed to heat. Steel is vulnerable to rapid loss of strength as temperatures rise, so it usually needs insulation or protective coatings to slow heat transfer and keep its structural capacity during a fire. Concrete, on the other hand, has inherent fire resistance because of its mass and low heat transfer, but it isn’t entirely invulnerable. To maintain overall fire resistance, concrete elements still require proper detailing to prevent spalling and to protect reinforcing steel—ensuring the concrete cover remains intact and the embedment keeps its integrity. That combination—steel needing insulation or coatings, concrete relying on its inherent resistance with careful detailing to avoid surface damage—matches the best description of how passive fire protection differs between the two materials.