AASHTO PP 91-18 (2020) PDF Download

AASHTO PP 91-18 (2020) is a standard practice that provides guidelines for the design of emulsified asphalt scrub seals. The standard focuses on determining the appropriate application quantities for both the aggregate and emulsified asphalt used in the scrub seal process.

A scrub seal is a specific type of pavement maintenance treatment that involves a four-step process. First, emulsified asphalt is applied to the pavement surface. Immediately after application, a scrub broom is used to push the emulsion into the cracks in the pavement, ensuring proper penetration. Following this, a single layer of cover aggregate is applied and then compacted using a pneumatic tire compactor. It is important to note that a fog seal may also be included in the process to enhance chip retention.