What Is Porous Asphalt?
Porous asphalt pavement is comprised of a permeable asphalt surface placed over a granular working platform on top of a reservoir of large stone. The asphalt surface is made permeable by building it with an open-graded friction course. The layer underneath the porous asphalt has the storage capacity to hold the collected water. In the late 1960s, the concept of porous asphalt was proposed to promote percolation, reduce storm sewer loads, raise water tables and replenish aquifers.” Throughout the 1970s, the concept was refined to a point where the Environmental Protection Agency sponsored projects to determinethe capabilities of several types of porous pavements for urban runoff control in terms of cost and efficiency. Where Does It Work? To find out if porous asphalt will work on a proposed project, designers must consider some key factors. Soil characteristics, local topography and climate are physical factors that must be used in designing porous asphalt pavement. The proposed uses o
