What Is Permeable Pavement?
Permeable pavement is a great choice for storm water management; while it’s raining, it will reduce water runoff from the surface. A poorly designed runoff system leads to water pooling in some areas as well as flash flooding which can cause fatal accidents on highways.
Porous Asphalt (PA)
One type of permeable pavement is porous asphalt (PA). For low-volume pathways like parking lots, it is possible to use a porous asphalt (PA) mixture but for high-volume streets and roads, two layers of asphalt (1. Asphalt-treated permeable base, 2. Porous asphalt) need to be used.
Porosity and infiltration rates of PA have a direct connection to available air voids in PA. Higher air voids in PA means higher porosity and infiltration. On the other hand, higher air voids in PA means less strength and durability of the pavement.