Performance-Based Mix Design for Porous Friction Courses

TRB's National Cooperative Highway Research Program (NCHRP) Research Report 877: Performance-Based Mix Design for Porous Friction Courses presents a proposed mix design method for porous asphalt friction course (PFCs).

PFCs have been used in the United States for many years. Their open aggregate gradations and resultant high air void contents provide PFCs with the ability to quickly remove water from the surface of a roadway, thus reducing the potential for vehicles to hydroplane and improving skid resistance. Splash, spray, and glare are also reduced, improving pavement marking visibility in wet weather. PFCs can also provide additional environmental benefits by reducing the pollutant load of storm water runoff as well as traffic noise.

Despite their many benefits, the use of PFCs has been limited in part because of cost, lack of a standard mixture design method, premature failure by raveling or stripping, and loss of functionality by clogging with debris. In addition to the need to develop improved maintenance methods to address clogging, the performance of PFC mixtures will benefit from the development of a standardized mixture design method that balances durability in terms of resistance to premature failure with functionality in terms of permeability and noise reduction.

The goal of this project was to achieve the required balance in the mix design between PFC durability and functionality.