Hydrologic Comparison of Four Types of Permeable Pavement and Standard Asphalt in Eastern North Carolina

摘要

A permeable pavement parking lot in eastern North Carolina consisting of four types ofpermeable pavement and standard asphalt was monitored from June 2006 to July 2007 forhydrologic differences in pavement surface runoff volumes, total outflow volumes, peak flowrates, and time to peak. The four permeable sections were pervious concrete (PC), two types ofpermeable interlocking concrete pavement (PICP) with small-sized aggregate in the joints andhaving 12.9% (PICP1) and 8.5% (PICP2) open surface area, and concrete grid pavers (CGP)filled with sand. The site was located in poorly drained soils, and all permeable sections wereunderlain by a crushed stone base layer with a perforated underdrain. All permeable pavementssignificantly and substantially reduced surface runoff volumes and peak flow rates from those ofasphalt (p<0.01). Of the permeable pavements, CGP generated the greatest surface runoffvolumes (p<0.01). The PICP1 and CGP cells generated significantly lower outflow volumesthan all other sections evaluated (p<0.01), and had the lowest peak flows and the longest time topeak. The response of the PICP1 cell was likely due to an increased base storage volumeresulting from an elevated pipe underdrain; whereas, the CGP cell response was attributed towater retention in the sand fill layer. Overall, different permeable pavement sections performedsimilarly, but were substantially different from asphalt. Subtle differences in the performance ofCGP were primarily due to the characteristics of the sand filled media compared to smallaggregate typically used in PC and PICP joints and bedding.