Optimizing the Design of Permeable Friction Courses (PFC) (0-5262-S)

This project summary report summarizes the research performed in Texas Department of Transportation (TxDOT) Project 0-5262. The main objectives of this research project were to develop and recommend an improved porous or permeable friction course (PFC) mix design method, and to develop guidelines for construction and maintenance of PFC. Researchers performed an information search, which they used to define an experimental design directed to evaluate four main aspects of PFC mix design: volumetrics, functionality (or drainability), durability, and aging. These aspects were evaluated for both performance grade (PG) and asphalt rubber (AR) asphalt systems in laboratory mixed-laboratory compacted (LMLC), field mixed-laboratory compacted (FMLC or plant mixes), and field mixed-field compacted (FMFC or road cores) specimens and corresponding extracted binders. An extensive laboratory and field testing program included multiple projects from eight TxDOT districts. Researchers recommended an improved PFC mix design method. They also suggested implementation of this method and future research in terms of tracking PFC performance toward selecting a laboratory functionality parameter for use in mix design, and evaluating and validating the durability parameters.