Real estate developers, municipalities and even individual homeowners are realizing the benefits of porous asphalt pavement as an investment on their projects. Porous asphalt pavement is an environmentally-conscious and sustainable paving solution that can manage stormwater runoff and offer long-term cost efficiency.
How Does Porous Asphalt Pavement Work?
Porous asphalt generally looks like standard asphalt, but is composed of an open graded friction course that is manufactured with larger aggregates and little to no fines to achieve a porous surface course. Stormwater runoff is then allowed to drain through the porous asphalt surface and into a stone bed below where it slowly infiltrates into the sub-soil as nature intended. If toxins are on the surface, they get swept along with the rainfall through the stone bed. From there, they travel into the sub-base so that they are subjected to the natural processes that cleanse water. The size and depth of the stone bed must be designed so that the water level never rises into the asphalt. Larger sediment becomes trapped or filtered out in the porous asphalt surface course, where it can be safely removed through light jet washing or with a vacuum-sweeper vehicle.
How Long Does Porous Asphalt Last?
With proper maintenance, porous asphalt pavement can last up to twenty years before showing cracks or potholes. It is a very durable product and it retains the ability to handle rainwater for many years. Porous asphalt has been used successfully in parking lots, walkways and bike paths, playgrounds and high-volume highways that carry heavy trucks. Porous asphalt tends to be a little coarser than standard asphalt due to the lack of fine aggregate, but is smooth enough to meet the Americans with Disabilities Act (ADA) accessibility requirements and is still an attractive option to consider during the development process.
Porous Asphalt Can Save You Money.
Along with the environmental benefits that porous asphalt brings, there are also cost benefits associated with this paving process. Porous asphalt can save you money because it eliminates the need to dedicate a separate area of your site to put in a stormwater management feature such as a detention basin. The land that is normally slated for the detention basin can be developed and used as a profitable asset that adds value to the property.
Another advantage of porous asphalt paving is that asphalt does not require special or proprietary ingredients to be manufactured. Most asphalt plants can readily prepare the mix and since installing it does not require additional paving equipment, general paving contractors can install it as they would other paving projects; although, experience does not hurt.
If you are considering repaving your parking lot or developing project that involves paving, consider porous asphalt, and contact VNHA to assist with your development project and help you realize the benefits of porous asphalt.
Brian Perry, PE is a LEED Accredited Professional who holds a Master’s Degree in Water Resources & Environmental Engineering and is a Senior Project Manager at Van Note-Harvey Associates, Inc. VNHA has been responsible for the design, permitting, and construction of over 30 projects involving porous pavement, spanning across Central and Southern New Jersey.