3.6: Pavement Distress Examples
Alligator Cracking
Block Cracking
Distortions
Distortions are usually caused by corrugations, bumps, sags, and shoving.
They are localized abrupt upward or downward displacements in the pavement surface, series of closely spaced ridges and valleys, or localized longitudinal displacements of the pavement surface.
Longitudinal and Transverse Cracking
Longitudinal cracks are parallel to the pavement’s centerline or laydown direction while transverse cracks are perpendicular.
Longitudinal cracks may be caused by poorly constructed paving lane joints, shrinkage of the asphalt concrete surface due to low temperature, or a reflective crack caused by joints and cracks beneath the surface course.
Patching and Utility Cut Patching
A patch is an area of pavement, which has been replaced with new material to repair the existing pavement. A patch is considered a defect no matter how well it is performing.
Rutting and Depressions
A rut is a depression in the wheel paths.
Rutting stems from a permanent deformation in any of the pavement layers or sub grade, usually caused by consolidated or lateral movement of the materials due to traffic loads.
Weathering and Raveling
Weathering and raveling are the wearing away of the pavement surface. This distress indicates that either the asphalt binder has hardened appreciably or that a poor quality mixture is present.