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In the case of high severity use overlays surface, or implementing to thin overlay.
4.4.5 Potholes
Low severity Medium severity
Figure 4.6 Severity levels of Potholes
a. Description
Small, bowl-shaped depressions in the pavement surface that penetrate all the way through the asphalt layer down to the base course. They generally have
sharp edges and vertical sides near the top of the hole. Potholes are most likely to occur on roads with thin asphalt surface 25 to 50 mm and seldom occur on
roads with 100 mm or deeper asphalt surface see Figure 4.6.
b. Problem
Roughness serious vehicular damage can result from driving across potholes at higher speeds, moisture infiltration.
c. Possible Causes
Generally, potholes are the end result of alligator cracking. As alligator cracking becomes severe, the interconnected cracks create small chunks of
pavement, which can be dislodged as vehicles drive over them. The remaining hole after the pavement chunk is dislodged is called a pothole.
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d. Options for Repair Cures
The treatments are surface patching or deep depend on depth of the hole. No matter what cure is chosen, it is important to fix the situation which caused the
pothole.
4.5.6 Patching
Figure 4.7 Patching
a. Description
An area of pavement that has been replaced with new material to repair the existing pavement. A patch is considered a defect no matter how well it
performs.
b. Problem
Roughness.
c. Possible Causes
- Previous localized pavement deterioration that has been removed and
patched. -
Utility cuts.
d. Options for Repair Cures
Repair distress in patch, Replace patch.
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4.4.7 Polished Aggregate
Figure 4.8 Polished Aggregate
a. Description
Polished aggregate is present when close examination of a pavement reveals that the portion of aggregate extending above the asphalt is either very small
or there are no rough or angular aggregate particles to provide good skid resistance.
b. Problem
Roughness.
c. Possible Causes
Aggregate polishing is caused by repeated traffic applications.
d. Options for Repair
Surface treatment using polish resistant aggregate.
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4.4.8 Raveling and Weathering
Figure 4.9 Raveling and Weathering
a. Description
Weathering and raveling are the wearing away of the pavement surface caused by the loss of asphalt or tar binder and dislodged aggregate particles. This
distress indicates that either the asphalt binder has hardened appreciable or that a poor quality mixture is present.
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.
b. Problem
