Green Patios, Walkways & Driveways of Porous Pavement and Pervious Concrete
(Page 2 of 4)
April/May 2009
By Dan Chiras
When replacing or creating a driveway or parking area, consider either permeable pavers or open-cell concrete blocks. These blocks are designed to support vehicles, but are sufficiently open to allow water to drain through them. The spaces are filled with gravel or sand. Grass or low ground cover can grow in the open spaces, which helps reduce heat buildup.
RELATED CONTENT
Getting the right rocks can be as challenging as picking the proper plants...
Amateur winemaker shares advice from his own personal experience....
ENERGY FLASHES January/February 1980 A SHORT HALF-LIFE MEMORY: Alvin M. Weinberg, one of the pionee...
You've probably seen a tree trunk-type footrest before, in which case you don't need me to tell you...
Another product that can be used for driveways is pervious concrete, aka porous pavement. As its name implies, this is a highly porous form of concrete. It’s made from aggregate (small stones) and cement, which binds the aggregate together. However, unlike conventional concrete, pervious concrete contains little, if any, sand. This results in a substantial number of open spaces in the concrete, basically a lot of holes through which water can flow into the ground.
Porous pavement is recommended by the U.S. Environmental Protection Agency and geotechnical engineers across the country to help manage storm water runoff. To learn more and find sources of materials, visit perviouspavement.org
and paversearch.com.
Two other intriguing options are Gravelpave2 and Grasspave2, made by Invisible Structures. Gravelpave2 is used for driveways, parking areas and pathways. It’s composed of plastic rings in a grid with a porous geotextile fabric molded to it. The grid and fabric are anchored to a porous base of sand or gravel. The grid is then filled with decorative gravel, forming a driveway or path that allows water to drain easily into the soil beneath. Check the company’s website for photos of numerous applications.
Grasspave2 also is used for parking areas and driveways. The ring-and-grid structure rests on a sandy gravel base. The voids are filled with “sharp sand” (sometimes called “builder’s sand,” it has jagged, not rounded, edges). The other ingredients, supplied by Invisible Structures, consist of a mixture of Hydrogrow polymer (the water-retaining material used in disposable diapers) and fertilizer. Grass seed or sod is planted on this mixture. Like Gravelpave2, this product allows for easy drainage, provides stability for driving or parking cars, and adds aesthetic value to a property. (The grass needs to be mowed from time to time.)
