Pervious Pavements in Cold Climates

Yesterday I wrote Pervious Pavements Reduce Stormwater Runoff and it received several questions/comments about the applicability in cold climates.

The first thing I wanted to point out was this pavement type is not meant for roadways, it's meant parking areas, driveways, walkways, etc. Some people have voiced a concern about frost heaves with regard to roads which really isn't what I was writing about.

However, even for parking lots and other non-road applications the creation of frost heaves will eventually deteriorate the pavement. However, the use of proper sub-bases will greatly reduce the occurrence and severity of frost heaves.

As you can see in the photo (Cahill Associates) the pavement surface is not the only component of a successful porous pavement application. The sub-base creates a layer for water storage and recharge. That layer contains stone aggregate with a large area of voids. Without writing a whole thesis on frost heaves, the large void areas will help drastically reduce the number and severity of frost heaves. Frost heaves are most prevalent in poorly drained silty type soils where the water can't escape easily and ice lenses form.

It's also worth pointing out that porous pavements have been used successfully in Norway and other parts of North America with very cold climates.

Tags: green construction, green construction blog, porous pavement, pervious pavement