15 March 2001
DISTRESS 51, POLISHED AGGREGATE
13.1. Description. Aggregate polishing is caused by repeated traffic applications. 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. Existence of this type of distress is also indicated when
the number on a skid resistance rating test is low or has dropped significantly from previous
ratings. A deduct curve for polished aggregate is shown in Figure 13.1.
13.2. Severity Levels.
No degrees of severity are defined. However, the degree of polishing should be significant
before it is included in the condition survey and rated as a defect (Figure 13.2.).
13.3. How to Measure. Polished aggregate is measured in square feet (square meters) of
surface area. If bleeding is counted, polished aggregate is not counted in the same area.
13.4. Options for Repair.
Do nothing; overlay; surface friction course.