Publication Number: FHWA-RD-02-006
Date: January 2002

International Conference Showcases Recycled Material Uses

From recycling asphalt pavement to finding new uses for lead paint removed from steel bridges, the first international conference on the "Beneficial Use of Recycled Materials in Transportation Applications," held in Washington, DC, in November 2001, provided a broad forum for sharing best practices and innovations. The conference brought together more than 160 experts from 15 countries in North America, South America, Europe, and Asia to address the use of recycled materials generated from transportation, industrial, municipal, and mining processes in transportation applications. Event sponsors included the University of New Hampshire's Recycled Materials Resource Center (RMRC), Federal Highway Administration (FHWA), National Asphalt Pavement Association, National Science Foundation, U.S. Department of Energy, Rubber Pavements Association, and the American Coal Ash Association.

The 3-day conference offered more than 130 technical presentations on topics such as programs, policy and analysis, materials applications and demonstrations, and evaluation methodologies. It also offered the opportunity to share ideas and experiences. "I appreciated the chance to talk to researchers from other countries and learn about their strategies for evaluating recycled and waste materials," says attendee Jeanne Hewitt of the New York State Department of Transportation.

A presentation on "Minnesota's Experience in Implementing the Use of Recycled Materials" made by Roger Olson, a Research Operations Engineer for the Minnesota Department of Transportation (DOT), explained the DOT's proactive stance on the use of recycled materials in transportation applications. Minnesota's standard criteria for using recycled material is that it must be:

• Equal or better in engineering applications;
• Environmentally acceptable; and
• Equal or better in economic considerations.

"Minnesota has gone through the evolutionary process of evaluating recycled materials: the normal process of environmental assessment, laboratory evaluation, and finally field tests," says Olson. This process has, at times, led to the development of a market for a particular recycled material, as was the case of using recycled asphalt pavement in hot-mix asphalt.

Kevin Wideman, the Environmental Compliance Coordinator for the Missouri DOT, delivered a presentation on "Lead-Paint Recycling in Missouri," which described the DOT's innovative lead paint removal techniques. Prior to 1990, paint removed from steel bridges was allowed to fall to the ground. When health and environmental concerns over this practice were identified, sand-blasted paint was then collected and stored in drums in landfills, with some bridges producing more than 100 drums of residue. In 1994, the Missouri DOT began recovering the lead through a smelting process that resulted in the recycling of hundreds of tons of former waste and saving valuable landfill space.

In an effort to improve the paint removal process, the DOT purchased two abrasive recycler blasters in 1996. These machines remove lead paint with vacuum washers and magnetic separators that reduce blast residue by an estimated 80 percent. Instead of 50 drums from an average bridge, there are now only 6 to 10 drums of residue that require the smelting process. These and other developments have greatly reduced the cost of disposal and eliminated any long-term liability for the department.

A research needs session was held at the end of the conference that included a panel of experts from FHWA, the U.S. Environmental Protection Agency, American Association of State Highway and Transportation Officials, the Association of State and Territorial Solid Waste Management Officials, and industry. The panel is currently working on a white paper that will help direct future efforts in recycled material research. The paper will be delivered to the National Science Foundation and Federal and State agencies.

A team is currently working on releasing the conference's proceedings in book form this year. The RMRC will announce the book's availability on its Web site at www.rmrc.unh.edu.

For more information on the conference and the use of recycled materials in transportation applications, contact Taylor Eighmy at RMRC, 603-862-1065 (fax: 603-862-3957; email: t.eighmy@rmrc.unh.edu).

Back to Articles in this Issue