Polished Aggregate


Areas of pavement (either PCC or HMA) where the portion of aggregate extending above the asphalt binder (in the case of HMA) or cement paste (in the case of PCC) is either very small or there are no rough or angular aggregate particles.

Figure 1: Polished PCC aggregate after 40 years of wear.

Figure 2: Close up of polished Hot Mix Asphalt aggregate.

Figure 3: Aggregate from two different SMAs at NCAT test track.


Decreased skid resistance

Possible Causes

Repeated traffic applications. Generally, as a pavement ages the protruding rough, angular particles become polished. This can occur quicker if the aggregate is susceptible to abrasion or subject to excessive studded tire wear.