Functionally Optimized Wearing Course

The preliminary findings on the design, production, placement, and early life performance of a new generation open-graded surface course [also referred to as porous friction course (PFC)] for use in Virginia are highlighted. The primary objective of the larger research project is the design of a functionally optimized asphalt concrete wearing course. Important aspects of the mix design and construction and the initial functional quality of the new surface are documented. General observations associated with the trial section and normal production and placement activities are accompanied by a summary of the quality characteristics of the material. Special emphasis is placed on the early life functional characteristics of the new wearing course. Among these key characteristics are ride quality, wet skid resistance, and tire–pavement noise. Observations made during trial production and placement led to lighter (thinner) recommended application rate and reduced asphalt concrete mix temperatures. Preliminary functional tests indicated that the PFC has exceptional early-age skid resistance, incentive-quality smoothness, and low tire–pavement noise. On the basis of initial cost and early-life functional performance, the PFC is cost-competitive with traditional mixes placed at traditional application rates (when those mixes are used for functional rather than structural improvement).