Porous Asphalt Pavement

In Porous Asphalt Pavement, you'll learn ...

• How urbanization alters the physical, chemical and biological environment within surface waters
• What is porous asphalt pavement (PAP)
• How PAP promotes water infiltration instead of runoff
• Applications where PAP can be a viable alternative to conventional pavement

Overview

Credit: 1 PDH

Length: 14 pages

Urbanization is an increasingly pervasive land cover transformation that significantly alters the physical, chemical and biological environment within surface waters. Specifically, urbanization results in the prevalence of impervious surfaces including roads, parking lots, driveways, and sidewalks. Impervious surfaces associated with urbanization reduce infiltration and increase surface runoff, altering the pathways by which water (and any associated contaminants) reach urban streams. Such runoff can lead to changes in water/sediment quality, water temperature, hydrology, and physical habitat for flora & fauna.

Porous asphalt pavement offers an alternative to conventional impervious asphalt pavement. Porous asphalt pavement has an open-graded asphalt surface course over an underlying stone reservoir (recharge bed). The water drains through the porous asphalt and into the stone bed; and then slowly infiltrates into the subgrade soil.

Porous asphalt pavement promotes water infiltration instead of runoff. Furthermore, its multiple layers of aggregate courses promote filtration of contaminants. This combined action of infiltration & filtration can reduce surface runoff volume and peak flow, as well as reduce contaminant levels, thereby improving compliance with state & local discharge permits.

This course is intended primarily for civil engineers who manage pavement projects for pathways, parking lots, low-volume roadways, and roads with infrequent heavy traffic, especially in areas with high precipitation or poor drainage. The course is also suitable for engineers involved in erosion control, stormwater management and water treatment, who would like to learn about an alternate technology for increasing infiltration and reducing stormwater runoff. The student should be familiar with basic soil properties such as gradation and classification.