Aluminum structural members fail at what temperature in a fire exposure?

Aluminum structural members fail at what temperature in a fire exposure?

• A. 800 Degrees F
• B. 1200 Degrees F
• C. 1000 Degrees F
• D. 1800 Degrees F

Answer: (B)

Aluminum structural members fail in a fire when the metal loses its ability to carry load as it softens and approaches its melting point. Aluminum alloys used in structures have a melting range around 1220–1250°F (about 660°C). As fire temperature climbs, strength and stiffness drop rapidly, and once the material nears its melt range it can no longer sustain the design loads, leading to failure. That’s why about 1200°F is cited as the failure temperature: it corresponds to the onset of substantial loss of integrity, whereas lower temperatures like 800°F or 1000°F still leave the member with some strength, and much higher temperatures would imply the metal has melted.

Aluminum structural members fail in a fire when the metal loses its ability to carry load as it softens and approaches its melting point. Aluminum alloys used in structures have a melting range around 1220–1250°F (about 660°C). As fire temperature climbs, strength and stiffness drop rapidly, and once the material nears its melt range it can no longer sustain the design loads, leading to failure. That’s why about 1200°F is cited as the failure temperature: it corresponds to the onset of substantial loss of integrity, whereas lower temperatures like 800°F or 1000°F still leave the member with some strength, and much higher temperatures would imply the metal has melted.