What is structural steel most vulnerable to regarding failure?

Structural steel is particularly vulnerable to fire because high temperatures can significantly compromise its strength and integrity. When steel is exposed to fire, it can lose up to 50% of its load-bearing capacity at elevated temperatures, and as the temperature rises, the steel becomes more ductile and less able to support loads.

This vulnerability to fire is critical during the design phase of a building, as proper fireproofing measures, such as fire-resistant coatings and insulation, must be implemented to ensure the continued safety and performance of the structure. While corrosion, earthquakes, and fatigue can also impact structural steel, the effects of fire are particularly destructive and immediate, often requiring specific safety measures to mitigate risks.