AASHTO PP 91-21

This standard practice determines application quantities for applying aggregate and emulsified asphalt for scrub seals.

A scrub seal is a four-step process in which the application of emulsified asphalt is followed immediately by a scrub broom to push the emulsion into the cracks in the pavement, followed with an application of a single layer of cover aggregate, and then rolled with a pneumatic tire compactor. There is the option of including a fog seal to help with chip retention.