Spalling

Summary

Spalling - is where small pieces of material (e.g. concrete, masonry or stone) break off from the main body of the material.

Technical Information

In concrete, spalling can be indicative of internal problems in the concrete, often caused by an expansion due to a chemical reaction or a physical process.

Spalling could be a symptom of:

Freeze-thaw weathering.
Alkali-silica reaction.
Sulphate attack.
Steel corrosion (from chloride diffusivity)

Spalling can also be used to describe the breaking away of concrete adjacent to a sawn joint. This can be avoided by ensuring the concrete has cured sufficiently prior to cutting, the time required will vary and is typically based on the contractors experience.