Examinations of Pervious Concrete and Porous Asphalt Pavements Performance for Stormwater Management in Northern Climates

In northern climates, runoff from standard pavements has varying seasonal effects on the surrounding environment. Year-round runoff carries transportation associated contaminants into surface waters. During the winter and spring, deicing practices for pavements result in high levels of chloride-laden runoff that is both toxic to aquatic biota and degrades drinking water supplies. The use of pervious pavements for parking lots for new and redevelopment projects are one watershed-based strategy that can both mitigate impacts for new development and reverse impacts in areas with redevelopment. This study presents the findings from 2 pervious pavements, a pervious concrete and a porous asphalt parking lot, studied at the University of New Hampshire Stormwater Center. Winter in particular places great demands on pavements however it was observed that due to the well-drained nature of the reservoir base that freeze thaw was limited. Surface infiltration rates, frost penetration, degree of snow and ice cover, and surface friction were measured on a monthly basis to assess winter performance. Frost penetration was observed to reach depths of eighteen inches however, surface infiltration capacities remained in excess of 200-in/hr. Analysis of snow and ice cover and pavement skid resistance demonstrated that up to 75% less salt was needed for porous asphalt to maintain equivalent or better surface conditions as the reference dense mix asphalt lot. The annual median snow and ice surface cover for the porous asphalt lot was not significantly different than the reference lot with salt applications four times greater (p=0.749 @95% CI). The annual median weighted skid resistance for the porous asphalt lot was 12% greater than the reference lot with greater salt application (p=0.061 @95%CI). Pervious concrete did not demonstrate substantial salt reduction capabilities during storm events; however, `black-ice' formation did not occur during freeze-thaw conditions indicating possible annual reductions. Pavement color and shading were found to be major factors influencing the amount and duration of snow and ice cover on the pervious concrete lot.