Swelling
A swell is characterized by an upward bulge in the pavement's surface. A swell may occur sharply over a small area, or as a longer gradual wave. Either type of swell can be accompanied by surface cracking. A swell is usually caused by frost action in the subgrade or by swelling soil, but a small swell can also occur on the surface of an asphalt overlay (over PCC) as a result of a blowup in the PCC slab.
Severity | Distress Example | Description |
---|---|---|
Low | Swell is barely visible and has a minor effect on the pavement's ride quality. Low-severity swells may not always be discernible, but their existence can be confirmed by driving a vehicle over the section. An upward acceleration will occur if the swell is present. | |
Medium | Swell can be observed without difficulty, and has a significant effect on the pavement's ride quality. | |
High | Swell can be readily observed and severely affects the pavement's ride quality. |