AASHTO PP 93-18 (2020) PDF Download

AASHTO PP 93-18 (2020) is a standard specification that provides guidelines for designing asphalt tack coats. Tack coats are thin layers of asphalt binder applied between pavement layers to improve adhesion and promote bonding. This specification focuses on determining the appropriate application rate for two types of asphalt binders: emulsified asphalt and performance-graded (PG) asphalt.

The specification emphasizes the importance of selecting the correct binder and application rate to ensure the tack coat effectively bonds the pavement layers together. It provides detailed testing procedures for determining the application rate based on factors such as surface conditions, temperature, and binder type. The goal is to achieve proper coverage and bonding without over-applying the tack coat, which can lead to rutting and other issues.