Loose materials (usually aggregate) that "ravel" from the surface or edges of the pavement, resulting in depressions which may fill with moisture and loose aggregate which may pose problems.
Causes
- Asphalt binder unable to hold aggregate in place
- Dusty aggregates
- Segregation of the mix during construction
- Low in-place density (insufficient compaction)
- Aged asphalt binder
- Stripping (moisture damage)
Solutions - Cures
If the cause is superficial, a surface treatment will solve the problem. If poor drainage is causing a stripping problem, the drainage should be corrected.
Solutions - Prevention