What is the average time to failure for cast iron columns under extreme conditions?

The average time to failure for cast iron columns under extreme conditions, which is stated as 30 minutes, is based on their susceptibility to heat and stress. Cast iron, while strong in compression, has a relatively low tensile strength and becomes brittle when subjected to high temperatures. Under extreme fire conditions, the integrity of cast iron structures can deteriorate rapidly.

The 30-minute figure represents a critical threshold where cast iron columns are likely to lose their structural integrity due to the extreme thermal exposure that causes significant weakening. This time frame is crucial for firefighters and engineers when planning for structural safety during emergencies. It allows for the assessment of risks and helps in decision-making regarding evacuation and firefighting strategies. Understanding these limits is essential for effective fire management and safety protocols within structures that utilize cast iron columns.