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It is up to manufacturers and road builders to capitalize on Wisconsin's decision to allow recycled roofing shingles in asphalt mixes for state road projects. Prompted by rising oil prices, the Wisconsin Department of Transportation instituted the change Jan. 1 -- in time for the first round of 2009 project bids, said Tom Brokaw, WisDOT materials lab supervisor. Asphalt made from shingles saves money because the recycled shingles replace petroleum… But realizing those savings could take time, according to manufacturers. The new technology requires new equipment and a new market. It also means collecting shingles to convert into asphalt, though shingles certainly are available. "Right now, I wouldn't say there's automatically going to be savings," said Scot Schwandt, executive director of the Wisconsin Asphalt Pavement Association. Some asphalt contractors and manufacturers -- including Elkhorn- based B. R. Amon & Sons Inc. and Payne & Dolan Inc., Waukesha -- are developing processes to grind shingles into half-inch pieces added to asphalt mixes that meet state standards, Schwandt said.
Source: http://findarticles.com/p/articles/mi_qn5302/is_20090120/ai_n31209510/
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State road projects may soon warm up to the green movement if a new method to produce asphalt with fewer greenhouse gas emissions proves successful. The Texas Department of Transportation is using "warm" asphalt for a three-mile-long paving project on Texas 71 near Austin-Bergstrom International Airport this week. Warm asphalt is mixed at 240 degrees, compared with 330 degrees for traditionally used hot asphalt . The lower temperature reduces the amount of chemicals released into the air. "Very few industries in this country have the opportunity to reduce their environmental footprint by 50 percent, so to have the sort of emission reductions as dramatic as we are seeing for this process is very significant," said Jonathan Maclver, a business development manager for MeadWestvaco Corp. , the company that came up with the process. Contractors and manufacturers say the so-called green asphalt is more expensive than traditional asphalt but is faster to mix and just as durable… "With conventional hot asphalt, you have to get it heated to 300-plus degrees first, but with the warm asphalt , it cuts about an hour off the time for you to start producing the asphalt ," Jackson said. Myles McKemie, vice president of marketing for Ergon Asphalt and Emulsions Inc., a co-partner in developing the warm asphalt process, said warm asphalt has the same durability as hot asphalt. He said some preliminary tests at the National Center for Asphalt Technology at Auburn University show that the process may even slow down the "aging" of asphalt, extending its life.
Source: Regina Dennis. "State repaving Texas 71 with new 'green' asphalt." Austin American-Statesman (TX) 4 Jun. 2008, Final, Metro: B05. Access World News. NewsBank. University of Texas at San Antonio, John Peace Library. San Antonio, TX. 14 Apr 2009
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Excerpt: Shortages of asphalt and its key ingredients threaten to delay up to $275 million in summer-paving projects, state transportation officials said today. The shortages are affecting 34 of the Colorado Department of Transportation's paving projects statewide, said CDOT spokeswoman Stacey Stegman… A shortage of liquid asphalt is occurring, in part, because oil refiners are concentrating on producing more profitable finished products from crude oil, such as diesel fuel, instead of asphalt, said Tom Peterson, executive director of the Colorado Asphalt Pavement Association. Refiners also are processing more light-crude petroleum, which produces less asphalt than heavy crude, Peterson added. Liquid asphalt is mixed with rock and sand to produce hot mix asphalt for paving roadways. CDOT specifies that a chemical polymer be added to the hot mix to strengthen the pavement, especially in areas where traffic volume is high, such as interstate highways. A worldwide shortage of this polymer is compounding the problem for CDOT and asphalt paving contractors in Colorado, Peterson said.
Source: http://www.denverpost.com/ci_9879699?source=rss
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The International Conference on Warm-Mix Asphalt, held recently in Nashville, TN, attracted nearly 700 people, including 70 international attendees. This was the largest single-subject conference ever for the asphalt pavement industry, and a live Internet feed extended the reach of the conference to hundreds more around the globe. At the start of the program, participants heard from the leadership of Federal Highway Administration (FHWA), National Institute for Occupational Safety and Health (NIOSH), the labor unions, and U.S. Environmental Protection Agency (EPA) on the importance of warm-mix technology. King Gee, an associate administrator of FHWA, emphasized the usefulness of warm mix in the reuse and recycling of asphalt pavements… The meeting featured presentations on materials; mix design; state, contractor and international experience; and plant operations. Dale Rand of the Texas Department of Transportation discussed how his state will use around 400,000 tons of warm-mix asphalt in 2008, and the prospect for 2009 is that much more will be used in that state. While Texas is acknowledged as a leader in warm-mix implementation, numerous other states are also moving in the direction of issuing permissive specifications which would allow contractors to use warm mix in place of hot mix as long as the resulting pavement met the specifications for the project.
Source: http://www.acppubs.com/article/CA6623879.html?industryid=48555
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Excerpt:
The Center for Transportation Research at the University of Texas at Austin, and others like it, have performed successful tests mixing liquid rubber or recycled printer toner with asphalt. Still, petroleum remains part of the mix. It's a tough road for an industry faced with tripling liquid asphalt prices. "There is no viable alternative of which I'm aware," state Department of Transportation spokesman Peter Van Keuren said. DOT didn't have much luck using the old tires, either. The agency recently added shredded tires to a paving mix at four locations, and found the results unsatisfactory. The surface didn't last as long, negating the cost benefits of the new process. The tires were successful when mixed with the sand, gravel and stone used as the basic fill for bridge replacement projects, however. DOT used the combination when making improvements to bridges on Interstate 87 in Saratoga County. Crews layered a combination of soil and the shredded remains of about one million worn-out tires.
Source: http://www.bizjournals.com/albany/stories/2008/07/21/focus4.html
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