In the 1980s, porous asphalt pavement parking lots were used to reduce stormwater runoff from new developments. These early projects are still in service today. With today's concern for water quality, streambed erosion from development runoff, and a need to recharge vital underground aquifers, many of today's agencies are significantly revising stormwater runoff requirements on developments.
Porous, or pervious, asphalt pavements have been used to address these concerns for over 25 years. The concept is simple: Construct stormwater detention basins under the street and parking structures. These basins are designed to collect stormwater from structures, pavements and other areas of a development and hold the water until it can percolate into the soil. Porous asphalt pavement is then placed over the top of these basins. These pavements are designed to let the water flow through them and into the detention basin.
Porous asphalt pavement is commonly known as open graded asphalt concrete (OGAC), open graded friction course (OGFC), and permeable asphalt. OGAC/OGFC has been used by state DOTs and local agencies since the 1930's. Most highways constructed in Northern California use OGAC as a final wearing course. The permeable mix allows water to flow through the pavement and drain out the sides. This significantly reduces splash/spray from vehicle traffic and reduces glare from daylight or headlights. Another benefit of OGAC when used on highways is a reduction in vehicle noise.
In California, designers should consider utilizing Caltrans specifications for OGFC (Standard Specifications Section 39) and utilize a PG binder that is stiffer than the binder typically specified in the area. Typically these would be PG 70-10, PG 70-22 PM, or PG 76-22 PM.
PRESENTATIONS
CalAPA Porous Pavment Presentation
"Porous Asphalt Pavments With Stone Recharge Beds"
Revised in 2008
Presented in Ventura, Newport Beach, Oakland and Santa Cruz, CA
Click HERE to download.
Porous Pavement Presentation
Presented at CalAPA "Paving Green" Conference
Oct. 28, 2010 -- Sacramento, Calif.
By Roger Smith, asphalt pavement consultant and former executive director of CalAPA.
Click HERE to download.
PUBLICATIONS
Asphalt Pavment Alliance publication
"Cleaner Water wtih Asphalt Pavements"
Published in 2011
Click HERE to download.
ARTICLES
"Asphalt: The Right Choice for Porous Pavements"
HMAT Sept/Oct. 2003
Click HERE to download.
"Thinkging Green wtih Porous Asphalt"
HMAT May/June 2003
Click HERE to download.
"Porous Asphalt Pavement With Recharge Beds: 20 Years and Still Working"
Stormwater may/June 2003
Click HERE to download.
"Permeable Pavement: What's It Doing on My Street?"
Information and comparison of porous pavements
Univeristy of Rhode Island
November 2005
Click HERE to download.
"Porous Asphalt Pavement Project at Disneyland Resort Passes First Rain Test."
CalAPA "Asphalt Insider" Newsletter
April 27, 2009
Click HERE to view the issue.
"Asphalt -- Paving the Way to LEED Certification"
A White Paper published in 2010 by Stites & Harbison, PLLC
Click HERE to download.
VIDEO
Brief video clip shot in 2009 of a porous asphalt pavement application at Disneyland Resort parking lot during a rainstorm.
Click HERE to view.
Brief video clip shot in 2010 oin Kentucky of a porous asphalt pavement demonstration of water-draining properties using a water truck.
Click HERE to view
WEBSITES
Asphalt Alliance "Asphalt Roads" website, stormwater and porous asphalt pavement page. Click HERE to visit. National Asphalt Pavement Association (NAPA) Porous Pavement Page, which includes construction guidelines Click HERE to visit.
CALTRANS
Caltrans construction standard specifications:
For the index page to Caltrans Standard Specifications, click HERE. The OGFC specification can be found by opening the "39-100" document.
For the index page to the amendments to the Caltrans Standard Specifictions, click HERE. Open the file "S!-020H." The Section 39 "Amended to Read" can be found on Pages 125-180.
Caltrans and industry representatives, under the auspicies of the joint Caltrans-industry Rock Products Committee, have been meeting in 2010 to develop a pervious asphalt pavement standard and guidance documents. For more information, contact Mehdi Parvini of Caltrans at (916) 227-5848.
