Basic Operations Firefighter Certification Practice Exam

What is the term used when trapped moisture in concrete is heated to steam and expands, causing parts of the concrete to break away?

1. Cracking

2. Spalling

3. Fissuring

4. Spalling

The correct answer is: Spalling

The term that describes the process where trapped moisture in concrete is heated to steam, causing an expansion that leads to parts of the concrete breaking away, is spalling. When concrete experiences spalling, the surface layers may break off or flake away, creating defects. This phenomenon often occurs when the concrete is subjected to high heat, such as in a fire scenario, resulting in steam formation within the pores of the material. Spalling can severely compromise the structural integrity of concrete, making it a critical concern in firefighting and emergency response situations. Understanding this process is essential for firefighters and building safety professionals to assess damage and implement proper safety protocols following exposure to high temperatures. The other terms do not accurately represent this specific action. For instance, cracking generally refers to the formation of fractures due to tensile stress, while fissuring signifies narrow cracks that might not lead to significant material loss. Therefore, the specific nature of moisture turning into steam and causing material to flake away precisely fits the definition associated with spalling.