From Tech Transfer Newsletter, Summer 2006 » printer-friendly

Don't Trash California

By Margo Reid Brown, Chair, California Integrated Waste Management Board

California currently generates more than 40 million scrap tires annually. These discarded tires have lived out their purpose and can potentially threaten California's environment and our health if not managed properly. While more than 75 percent of this amount is recycled, the state still faces the challenge of handling more than 10 million surplus tires annually, the majority of which end up in landfills or, in some cases, illegal stockpiles.

What can be done to reduce environmental hazards of our remaining scrap tires?

The good news is that due to the passage of State Assembly Bill 1843 in 2000 and the establishment of the Tire Recycling Management Act, the California Integrated Waste Management Board (CIWMB) is leading a revitalized effort to recycle tire material. CIWMB provides assistance by promoting the use of rubberized asphalt concrete, commonly known as RAC and affectionately referred to as "rubber roads." Rubberized asphalt concrete, a paving product made from aggregates, asphalt cement and reclaimed tire rubber, is:

Cost effective. A two-inch-thick rubberized asphalt concrete overlay can save as much as $22,000 per lane mile when compared to a four-inch-thick conventional asphalt overlay. RAC also offers lower maintenance costs in the long run because it is more resistant to cracking than conventional asphalt concrete and, therefore, lasts longer.

A noise suppressant. One of the most compelling arguments for using RAC is its potential to quiet our roadways. Studies have shown that tire-pavement interface noise accounts for 75 percent of the noise generated from highways. RAC can reduce the noise at the source better than other materials, and research has shown that noise can be reduced by as much as 85 percent in some instances.

Long lasting. The durable pavement resists reflective cracking. Case studies have demonstrated that when designed properly, RAC lasts much longer than conventional, unmodified asphalt materials. These studies are supported by Caltrans testing.

Environmentally friendly. A two-inch-thick resurfacing project uses more than 2,000 waste tires per lane mile. This means that for a one-mile section of a four-lane highway, more than 8,000 tires can be used in creating a quieter, longer-lasting road. California has 310,000 lane miles of paved city and county roads. If just half of those roads were resurfaced using rubberized asphalt concrete, just imagine the cost savings and the space that would be cleared in landfills.

Success Stories

Thousand Oaks knows firsthand the benefits of using RAC. The city has been using the product since 1992. To date, Thousand Oaks has used rubber from 1.3 million discarded tires to resurface hundreds of miles of surface streets. The city found that the improvements—increased skid resistance, reduced road noise, improved riding qualities and imperviousness to water—have made the use of RAC cost effective and more desirable than traditional asphalt concrete.

Thousand Oaks is not the only city that has used RAC. The CIWMB awarded more than 60 grants totaling $4.2 million between January and April of this year alone. Many of these grants help first-time or limited-RAC users, including San Clemente, Fremont, Rancho Cordova, Brea, San Fernando, Galt, Ripon and Nevada City, to name just a few. Individuals, businesses, local governments, universities, school districts, park districts, and qualified California Indian tribes are also eligible to apply for the grants.

Grants Available

To make RAC grants easier to get, CIWMB has made them available on a monthly basis. To learn more about RAC and how you can benefit from using this product, contact the Waste Tire Grants Hotline at (916) 341-6441, e-mail the tire grants staff at tiregrants@ciwmb.ca.gov, or visit the CIWMB grants website at www.ciwmb.ca.gov/Tires/Grants.

©2006 Western City magazine. All rights reserved. Reprinted with permission from the July 2006 issue of Western City magazine, the monthly publication of the League of California Cities. For more information, visit www.westerncity.com.

2006 Asphalt Rubber Conference

This conference will be held October 24-27 in Cathedral City, CA. It will focus on design, life cycle cost, construction, research, maintenance, recycling, noise reduction, and production of Asphalt Rubber. For more information and to register, visit www.ar2006.net.

2006 Byproducts Beneficial Use Summit

Learn how recycling industrial byproducts can help your agency save money, meet regulations, and more at the 2006 Byproducts Beneficial Use Summit.

Rubber tires are not the only trash items that can be redirected on the way to the dump for a productive second life. Road byproducts like uncontaminated concrete, asphalt, brick, and rock can be reused as a substitute for conventional aggregate. Soil that is contaminated with petroleum can be reused as Hot-and-Cold mix asphalt crack and joint sealant or Hot-and-Cold mix asphalt concrete if it's not hazardous.

To learn more about how your agency can benefit from byproduct recycling, attend the Byproducts Beneficial Use Summit, which will focus on ways to recycle high-volume, low-hazard industrial byproducts and cover the obstacles to reuse and ways to overcome them. The Summit will be held November 29-30 in San Francisco. For more information and to register, visit www.byproductsummit.com/2006.

© 2008 Regents of the University of California