What is a material that is prone to spall under fire conditions?

Concrete is a material that can spall under fire conditions due to its physical properties. When exposed to high temperatures, the moisture trapped within the concrete can turn into steam. This steam generates pressure within the material, which can create cracks and cause pieces of concrete to break away from the surface, a phenomenon known as spalling.

This is particularly critical in firefighting because spalled concrete can pose risks to both firefighters and victims by leading to structural instability and falling debris. Understanding how different materials behave under fire conditions is essential for effective firefighting strategies and for ensuring safety during operations.

The other materials listed, such as steel, iron, and plastic, behave differently under fire. For example, while steel can lose strength at high temperatures, it does not typically spall in the same manner as concrete.