Volume7, Issue 1
January/February 2007

Specifiers are rapidly beginning to treat rainfall (stormwater) differently. Rather than piping stormwater immediately away to the nearest sewer or creek, designers are devising ways to temporarily "detain" the water on site, or better yet, enable it to pass into the ground. A new document is now available to assist, even for sites with clay soil and freeze-thaw weather.

The new document is entitled "Specifier's Guide for Pervious Concrete Pavement with Detention." As the name implies, it will assist the user in designing a concrete pavement that has a temporary stormwater storage system beneath it. Pervious concrete, with its open textured structure, gives the designer a rigid yet porous paved surface that rapidly allows rainwater to pass through it, and into a layer of clean coarse aggregate below.

Engineers, architects or landscape architects may use the guide in developing their designs to detain (slow down) stormwater to meet requirements on new or existing pavements. Pervious concrete pavement with detention can be constructed in parking lots, driveways or residential streets for new land redevelopments; or it can be used as partial replacement pavement for existing streets or parking lots to take pressure off of older and overloaded combined sewer systems.

The core text of the "Specifier's Guide for Pervious Concrete Pavement with Detention" was compiled by ORMCA staff engineers from specifications used in Georgia, California-Nevada, Oregon and Vermont. Feedback to the draft document was received from researchers and other professionals throughout the U.S. The draft plus feedback was reviewed by the ORMCA Technical Committee, and a final document was then approved by the ORMCA Board of Directors in their December 13, 2006 meeting.

The Ohio Ready Mixed Concrete Association (ORMCA) is a trade association representing most of the ready mixed concrete producers in Ohio. In addition to the 107 producer members, ORMCA has 96 associate member companies that provide the materials, equipment and services necessary to produce and deliver ready mixed concrete to public and private construction projects throughout the state. This new guide and other information pertaining to pervious concrete is available on the ORMCA Web site, www.ohioconcrete.org.