What does "spalling" refer to in masonry?

Spalling refers specifically to the breaking or flaking of masonry surfaces, which occurs when layers of material lift away. This can happen due to several factors, including freeze-thaw cycles, moisture intrusion, or poor-quality materials. Spalling can compromise the structural integrity of masonry, lead to further deterioration, and necessitate repairs to preserve the functionality and aesthetics of the building. Understanding spalling is crucial for maintenance and ensuring the longevity of masonry structures. Other options may describe related issues, but they do not capture the specific phenomenon of spalling, which is characterized by the physical disintegration of the surface.