Slippage Cracking

Slippage cracks are crescent- or half-moon-shaped cracks having two ends pointed away from the direction of traffic. They are produced when braking or turning wheels cause the pavement surface to slide and deform. This usually occurs when there is a low-strength surface mix or poor bond between the surface and next layer of pavement structure.

Guidance on identifying and measuring slippage cracking on AC-surfaced pavements.
Severity Distress Example Description
N/A Overview photo showing a series of crescent-shaped cracks on the pavement surface. Overview photo showing some signs of slippage cracking, but no visible cracks yet. In the photo, cut grooves in the pavement surface have noticeably warped due to turning wheels or braking.

No degrees of severity are defined. It is sufficient to indicate that a slippage crack exists.

The first photo shows a close-up of slippage cracking. The second photo shows an example of the initial stages of slippage cracking before any actual cracking of the pavement has occurred. The deformation is easily seen from the curvature of the transverse grooves in the asphalt surface.