Surface Deformation

Rutting

Displacement of material, creating channels in wheel paths.  Caused by traffic compaction or displacement of unstable material.  Sever rutting (over two inches) may be caused by base or subgrade consolidation.  Repair minor rutting with overlays.  Severe rutting requires milling the old surface or roadbed reconstruction before resurfacing.

 

Slight to Moderate - Even slight rutting is evident after rain.

 

Severe - Over two inches deep here.

Distortion

Shoving or rippling is surfacing material displaced crossways to the direction of traffic.  It can develop into washboarding when the asphalt mixture is unstable because of poor quality aggregate or improper mix design.  Repair by milling smooth and overlaying with stable asphalt mix.

Other pavement distortions may be caused by settling, frost heave, etc.  Patching may provide temporary repair.  Permanent correction usually involves removal of unsuitable subgrade material and reconstruction.

 

Rippling and Shoving - Heavy traffic has shoved pavement into washboard ripples and bumps.

 

Settling - Poor compaction caused settling over a culvert.

 

Frost Heave - Localized heave - probably boulder pushing upward.