100 percent RAP ready

Green Asphalt’s 100 percent reclaimed asphalt product (RAP) has Abeen in use in New York City for several years, and now the company is working with legislators, regulators and other asphalt producers to spread the use of 100 percent RAP beyond the Big Apple.

Green Asphalt is an affiliate of C.A.C. Industries Inc., a civil contractor. Both companies are based in Long Island City, Queens, New York. Created to recycle the wealth of used asphalt generated by construction projects around the city, Green Asphalt developed a 100 percent RAP product. C.A.C. uses Green Asphalt’s product on projects around the city, creating a closed-loop system for asphalt.

“To my knowledge, New York City is really the only city that explicitly allows 100 percent RAP,” Green Asphalt Chief Marketing Officer Kerianne Melillo says.

However, she says some states and municipalities are starting to permit asphalt mixes that are able to meet performance specifications.

“If you create a mix and it works, and it passes all of the tests, you can use it,” she says. “So, while they’re not explicitly saying you can increase your RAP content, they kind of are saying on the back end that if you can create a mix that fits these criteria with a higher RAP content [it can be used], and … that is a huge opportunity.”

She says Green Asphalt produces between 120,000 tons and 160,000 tons of RAP annually, mostly for use in the New York area.

Testing, data and regulations

Variations in state laws and regulations pose issues for many industries tackling different issues. Melillo says these variations also pose challenges for Green Asphalt and other companies producing RAP mixes.

“The United States is unique in and of itself because each state operates independently, especially on these types of things,” she says. “Even though balanced mix design and performance-based specs are being more widely adopted, they’re adopted differently in each state.”

Not only do states have different standards, but they also have different testing regimens once RAP is installed, Melillo says.

Because of frequent utility repairs underneath the city streets, she says it is difficult to find NYC roads that were paved using Green Asphalt’s 100 percent RAP during the company’s early years, which would be useful in providing longitudinal data to agencies that want to learn more about RAP’s lifespan.

“Asphalt in New York City rarely survives to see its full life cycle due to the constant repair of aging infrastructure,” she explains. “The oldest project that we tested was paved in 2018.”

Green Asphalt Vice President Jim McMurray says he spends a lot of time speaking with people who work for state departments of transportation trying to convince them to permit the use of 100 percent RAP.

“Every time we meet with an agency, we learn more about what they want from us,” he says. “At our last meeting … we thought we showed up pretty well prepared. We did some job profiles from a project that was done five years ago. We did some core samples on the job, sent the material out to be tested, and that testing all looked pretty good. But you show up and they want different data. They’re looking at the data, saying, ‘Oh, well, you know, this wasn’t performed in a lab. These were samples from the road.’”

McMurray says the National Center for Asphalt Testing at Auburn University oversees the standard for testing asphalt and other pavement. The center features a 1.7-mile track where special trucks simulate years of road use in a fraction of the time.

He says he wishes states also would accept data from streets that have undergone real-world use, which is what he provided in this recent case.

“What could be a better test track than 10 years of history and a million tons on city streets?” he says. “To me, it doesn’t get much better than that. It’s real. It’s real life.”

The city streets used for those samples have experienced a great deal of traffic and weather extremes.

“The Northeast gets the hot summers, the cold winters—it kind of gets the worst of everything—a lot of precipitation, ice; you really do get all of it,” McMurray says.

“Our biggest challenge in trying to promote our technology is that we’re going to have to sell it to someone with a similar mindset as we have, where they’re going to take a chance and go out on a limb and start doing the work.” – Jim McMurray, VP, Green Asphalt

Another challenge in providing data to regulators is a simple “Catch-22,” Melillo adds. “If our customers are not allowed to use anything more than 20 percent [RAP], we’re not going to be making anything more than that to collect data on,” she explains. “So, it’s like being between a rock and a hard place where they want all this data on higher content RAP before they allow it to be used.”

McMurray says the takeaway from those types of experiences is that patience and persistence are keys when trying to convince regulators to permit 100 percent RAP or to establish the standards the material would be able to meet.

“Our biggest challenge in trying to promote our technology is that we’re going to have to sell it to someone with a similar mindset as we have, where they’re going to take a chance and go out on a limb and start doing the work,” he says. “It takes a little bit of risk. It’s not so simple.”

Baghouse tech

One of the reasons Green Asphalt has been able to produce clean recycled asphalt relates to another set of rules— emissions regulated under the Clean Air Act.

Melillo says Green Asphalt has developed patented baghouse technology that it plans to license to other companies so they can produce 100 percent RAP without releasing harmful emissions.

“Our technology is essentially a patented baghouse that filters out the smoke that’s created [during production],” Melillo explains.

McMurray says producing RAP is a different process than producing asphalt from virgin materials.

“A traditional baghouse is meant to take the dust out of the virgin aggregate,” he says. “So, if you’re using sand and stone that’s not perfectly washed, it [creates] a lot of dust in the baghouse, and the baghouse removes that dust and either puts it back into the mix or pulls it out of it completely, and then you have to dispose of it.”

Photos courtesy of Green Asphalt

The challenge of producing RAP is that the aggregates already are coated in asphaltic cement and require special technology to safely reheat them.

“When you’re making a 100 percent mix, your aggregate is coated with the existing oil from the original asphalt. So, you don’t really have any dust,” McMurray says. However, blue smoke is generated during RAP production when the oil products in used asphalt are heated, he explains.

Plants that produce only virgin asphalt—and there are not many of those anymore—do not produce any blue smoke, he says. The higher the percentage of used asphalt that is incorporated into the mix, the more blue smoke that is generated, which has created the need for Green Asphalt’s baghouse technology.

“The baghouse is more of a blue smoke scrubber—a filtration unit that cleans the blue smoke out of the process,” McMurray says. “We’re working through our first licensing agreement with another company in New York, and then proposals have gone out to about five other plants in the U.S. and a couple in Europe. We’re on an active push to license this. For Kerianne and myself, that’s our big focus for the foreseeable future.”

Spreading the gospel

Although using RAP is a matter of convenience in urban areas given the steady flow of used asphalt available, McMurray says Green Asphalt’s baghouse technology is generating interest in other locales, as well.

“Ironically, we’ve got some asphalt plants that are in some rural areas, and they’re actually in quarries,” he says. “They’re interested in our technology, as well. They have massive stockpiles of RAP that they don’t know what to do with, so we’re not limiting ourselves to just the major metropolitan areas, but that’s one of our focuses to start.”

When working with companies outside New York, McMurray says Green Asphalt helps them initiate conversations with state agencies to permit higher content RAP.

“We usually have a contact in a state and will join the state association, and then we will usually try to set up a meeting with the state DOT [Department of Transportation],” he says. “We’ll go at it from all angles, and then we’ll also try to get some information in front of the representatives in Washington from that area.

“When we join the state association, they’re usually very interested in what we’re doing, and they invite us to either their annual meeting or semiannual meeting. We’ve already been asked to speak at three annual meetings this year,” McMurray says.

He says the company is not interested in building more plants nor in expanding across the country or the world.

“We believe that the goal should be for all asphalt to be green asphalt,” McMurray says. “And we think the best way to do that would be to help people convert their plants. Why go into another market and add a competitor in a market that’s already dominated by one or two people?”

The author is the managing editor of Construction & Demolition Recycling magazine and can be reached at bgaetjens@gie.net.