Development and Evaluation of Functional Open Graded Friction Courses (FOGFC) Mixtures for In Situ Highway Runoff Treatment

The use of Open Graded Friction Course (OGFC) pavements as road surfacing materials has grown considerably over the past decades. Acknowledged benefits include reduced splash and spray, better visibility, better traction, and less noise. Moreover, the installation of OGFC shows noticeable improvements of runoff water quality, which might be due to the retention of pollutants by internal pores. However, the traditional OGFC has little or no effects on the dissolved constituents, such as dissolved organic matter, dissolved copper and zinc in the stormwater. This study was conducted to correct this problem by adding additives into the OGFC mixtures to produce Functional OGFC (FOGFC), which has adsorption functions for dissolved constituents, such as organic matters and dissolved heavy metals commonly found in highway stormwater runoffs. The characteristics and environmental applications of this novel FOGFC were evaluated. Results indicated that FOGFC not only preserves OGFC's advantages in the removal of particulate pollutants, but also significantly extends its ability to remove non-particulates or dissolved pollutants, thus eliminating the needs of external treatment facilities to a certain extent.