Laboratory and Field Evaluation of Porous Asphalt Mixes

Porous asphalt concrete (PAC) generally has strongly open-graded aggregate gradations to yield high air voids, and is mainly applied to a surface drainage layer on high-speed trafficked highway pavements. Tests including durability and resistance to drain-down were conducted to determine the mechanical properties of PAC mixtures in the laboratory. The use of polymer-modified binder was shown to minimize the abrasion loss and enhance the durability of the PAC mixture. A test road was constructed to monitor the performance of PAC pavements based on the laboratory results. Surveys for pavement performance were conducted at scheduled intervals. Test results indicated that using polymer-modified binders instead of traditional binder improved drainability of PAC. Friction characteristics appeared to have no correlations with the binder type.