Turning Roofs Into Roads
|Shingles are ground into fine granules before being used to make asphalt pavement. Photo courtesy of Mike Ettner.|
B.R. Amon & Sons, Inc. and Rooftop Recycling, LLC, both of Elkhorn, WI, have teamed up to become Wisconsin's first companies to recycle asphalt roofing shingles for use in asphalt pavements.
Recycling the roofing material will not only keep mountains of waste out of the state's landfills, it also helps make asphalt pavements better and more economical.
In addition, it reduces the amount of new asphalt and aggregate that needs to be processed from the earth.
Amon First Company In State To Receive Permit
B.R. Amon & Sons and Rooftop Recycling are the first companies in Wisconsin to recycle asphalt roofing shingles into asphalt pavement.
Amon's role is to recycle the shingles and incorporate them into selected batches of the hot-mix asphalt itproduces.
Rooftop Recycling certifies the sources that provide the used shingles, coordinates the incoming shipments, screens the delivered shingles to be sure they meet Amon's specifications, separates the useable shingles from non-useable material such as nails and roofing paper, and cleans the shingles before turning them over to Amon for grinding and reuse.
Currently, Amon is the only company in Wisconsin to hold a Department of Natural Resources (DNR) permit to recycle asphalt shingles for use in hot-mix asphalt.
Rooftop Recycling's technical expertise enabled it to write the permit request on behalf of the hot-mix plant operator, and Rooftop Recycling also continues to provide Amon with regulatory consulting.
Opportunity To Help Environment
Says Tom Amon, P.E., president of B.R. Amon & Sons, "Ten other states are already recycling asphalt shingles into pavement, but Wisconsin is just now starting. This represents a huge opportunity to help the environment while also providing a high-quality paving material."
Experts estimate that 300,000 to 400,000 tons of residential tear-off shingles find their way into Wisconsin landfills each year. That represents about 30 percent of the total construction and demolition waste dumped into the state's landfills annually.
Mike Ettner, owner of Rooftop Recycling, had more than 20 years of landfill-management experience before founding his new company in the summer of 2007. Says Ettner, "I saw this continuous stream of shingles coming into landfills and thought that there must be a way to make use of them, instead of just filling landfills. Processing them for incorporation into asphalt pavement turned out to be a natural use that saves both money and the environment.
"It was a pleasure working with the forward-thinking regulators who helped with the permitting and licensing of Wisconsin's first asphalt-shingle recycling program," Ettner said.
"In particular, Ken Hein, Bob Grefe, Kate Cooper, and Dennis Mack of the Wisconsin DNR were especially helpful, as was the Federal Environmental Protection Administration — Region 5, which provided guidance as the permit for Amon moved forward," he said.
Long Experience Leads To Understanding
Tom Amon is now president of B.R. Amon & Sons, a family company started by his grandfather in 1918. The company bought its first crusher in 1927 and began producing hot-mix asphalt in 1950. It is well-known around the state as both an asphalt producer and paver.
|From top to bottom:
Top: Tom Arnon, left president of B.R. Amon Sons, and Mike Ettner, president of Rooftop Recycling, LLC, stand in front of a mountain of sorted shingles at Amon's yard near Elkhorn.
Middle: Initial sorting of processing separates useable shingles from other materials, such as nails.
Bottom: Recycled asphalt pavement, left, and recycled asphalt shingles, right, both work well in making new asphalt pavement.
The company now operates two stationary hot-mix plants, one near Elkhorn, WI, and another near Lake Mills, WI, not far from Madison. It also operates a portable plant that moves around the state to accommodate projects in other areas.
Tom Amon has spent his whole life in the family asphalt business, and has long served on the Wisconsin Dept. of Transportation (WisDOT) asphalt specification committee that sets the standards for asphalt used in paving state highways.
He knows the science of asphalt and sees the match between rooftops and roadways.
Shingles A Good Match For Asphalt Pavement
Amon says, "The materials in asphalt shingles are quite similar to the components used in paving asphalt, so they work well together."
A typical shingle, he says, contains 20- to 25-percent asphalt. The rest consists of fiberglass or cellulose paper fibers, sand, and fine aggregate, usually quartzite or granite.
That makes residential roofing shingles a good candidate for incorporation into paving asphalt.
Says Amon, "The fiber from the recycled shingles actually makes asphalt that incorporates them stronger and more durable than asphalt that doesn't include recycled shingle material."
"The practice of incorporating recycled asphalt pavement (RAP) and fractionated recycled asphalt pavement (FRAP) for use in new hot-mix asphalt pavements has been well established," Amon said. "Adding recycled asphalt shingles (RAS) is just the next logical step."
Typically, new hot-mix asphalt pavement that includes recycled shingles has been used on driveways and parking lots, but starting with the September 2008 bid lettings, WisDOT is approving its use for paving state highways, too.
Asbestos Rare, Not A Problem
According to Ettner, asbestos has not been used in residential roofing shingles since the 1970s, so roofs being torn off houses today rarely contain it. "Thousands of tests in many states have shown it's not a problem," he says.
But just to be doubly certain, Rooftop Recycling runs a test for every 50 tons of shingles that are ground up. Ettner says that if any of the tests detected asbestos in the ground-up shingles, it has been below the amount that needs to be reported and handled specially.
Well-Defined, Effective Process
The process starts when a pre-certified supplier's truck pulls up at one of the Rooftop Recycling/Amon facilities in either Elkhorn or Lake Mills.
Rooftop Recycling inspects the load to be sure it meets specifications and doesn't contain too much non-shingle material.
The truck is then weighed and the shingles are dumped. If the load contains only shingles, it goes into the "pre-sorted" pile; if not, it's dumped into a separate pile for hand sorting.
Hand sorting is labor-intensive, but it assures that metal, plastic, wood,cardboard, paper, and other undesirable materials are all removed.
Once sorted, the shingles are sent to a typical material grinder that pulverizes the shingles into fine granules that are deposited onto a stockpile at the adjoining asphalt-manufacturing plant, where they wait until a mix design calls for them.
When needed, the recycled shingle material is loaded into one of the bins that feeds the asphalt batch plant, just same as sand, aggregate, RAP, FRAP, and other raw materials.
From there, it is fed into the drum to be mixed with liquid asphalt binder in the standard asphalt-making process.
Mixes Tailored To Need, Savings Possible
Says Amon, "Our mix designer, Joe Kyle, relies on more than 20 years of experience to tailor mixes to virtually any performance specification, either using all virgin asphalt or asphalt with some recycled content. The ability to incorporate the most cost-effective combination of RAP, FRAP and recycled shingles into the asphalt mix can save paving customers money if they choose to use it."
The amount of savings depends on the price of oil and of virgin liquid asphalt. "Recycled shingles can make up anywhere from 5 percent to 10 percent of the new asphalt they become part of," says Amon.
"If 10 percent of the new asphalt comes from recycle shingles, and about 20 percent of the shingle content is asphalt, you'd save about 2 percent of the liquid binder cost," he said.
Some paving experts believe asphalt pavements made with recycled shingles actually resist wear, moisture, rutting, and cracking better than those made of all virgin asphalt.
The rule of thumb is to use up to 5-percent shingles for paving high-use highways and up to 10-percent shingles for driveways and parking lots.
Recycling Beneficial For Both Roofer And Paver
Recycling residential shingles for roadway pavement benefits both the roofer and the paver. (There is not yet a way to recycle commercial roofing material into asphalt pavement.)
Says Mike Ettner of Rooftop Recycling, "First of all, the roofer or demolition contractor saves money because our tipping fee is less than that of a landfill. In addition, it helps meet state-mandated recycling goals, and if LEED credits are important, recycling earns extra credits."
"Likewise," he continues, "Paving contractors and customers can save money by incorporating recycled products into their asphalt mix, and LEED credits are available for using recycled materials in pavements."
"Ecologically, we all benefit because it can help extend the life of our landfills, reduce production of greenhouse gases, and helps us use less oil,"Ettner said.