Five years ago, recycled asphalt shingles (RAS) found their place in the market.
In 2014, the paving industry utilized nearly 2 million tons of RAS to supplement mixes and lay down new roads, signaling a strong, growing customer base for a material often sent to landfill.
But as asphalt cement prices dropped, RAS use spiraled. The paving industry turned to cheaper raw materials instead, and by 2017, the amount of RAS used in roads declined by more than half.
Though the numbers are bleak, Asphalt Shingle Recycling Systems (ASR), based in Barrington, Rhode Island, remains unfazed. Since its founding in 2009, the company’s main goal has been to work alongside the roofing industry in North America to increase the sustainability of its businesses by finding end markets for RAS. Through the sudden downturn, the company has remained vigilant in realizing its goal.
“We want to see shingle recycling come back to its full potential,” says Alan Clarke, a partner at ASR Systems. “We’ve seen good times and we’ve been through bad times, but we believe things will come back around. But we, and others, need to be innovative in how we do that.”
Asphalt shingles, the roofing industry’s main source of waste, heads to landfills at a rate of nearly 90 percent nationally, according to ASR Systems.
Dan Horton aimed to minimize that rate when he left his executive position at IKO Industries, a roofing manufacturer, to establish ASR Systems in 2009.
The company has since processed more than 150,000 tons of RAS between its three facilities—two in Tennessee and one in Connecticut. There, roofers drop off their recycled shingles, and like most shingle recyclers, ASR runs them through reduction equipment to gnash the pieces into bits smaller than 3 /8 inches.
Processing, however, takes on other forms at ASR—and it’s just the beginning of the company’s involvement in recycling asphalt shingles.
Horton has been busy over the past decade developing new techniques for mechanical processing, separation and extraction of asphalt from shingles. He’s developed a “secret sauce” for processing, he says, and has written six patents over the past 10 years.
Two of the six patents relate to a new container design for collecting shingles from roofers in a way that is both convenient and cheaper than traditional methods. Three of the patents establish effective ways of extracting raw asphalt from the shingle mechanically to produce alternative roofing granules, asphalt coated limestone, limestone, recycled asphalt and recycled fiberglass strand powders.
“Asphalt itself is the most expensive part of the shingle. Because of that, the industry is focused on the use of that product,” Horton says. “I would never say that the asphalt paving industry is not the place to go with the product. I’m saying with better processing methods of a shingle, you may be able to sell more product to the asphalt paving industry.”
In addition, ASR offers its system for license to asphalt shingle recyclers, although Horton cautions that ample end markets still need to be established before the technology can be used to its fullest potential.
Now that ASR has established new collection and processing methods, though, developing end markets has become a focal point of Horton’s latest patent.
ASR Systems, like many asphalt shingle recyclers, saw initial success selling its end product to the paving industry. However, success quickly faded when problems began to arise.
Late in 2014, the Federal Highway Administration (FHWA) issued a memorandum noting that an increasing number of state departments of transportation reported premature cracking in relatively new asphalt pavements. The agency found the common factor among the cracked roads was a relatively high use of RAS.
Mixing RAS back into paving asphalt can be complex. Shingles are made of six raw ingredients, the most valuable of which is asphalt. When that asphalt is recovered, it’s nearly 20 percent harder than its original form. “In a word, the chemistry’s changed,” Horton says. “The change in chemistry is not a problem for pavement if you only use 3-5 percent of recycled material. If you use more than 5 percent, you may have to change the virgin asphalt portion of your design to compensate for the hardness of the recycled asphalt.”
Studies since then, including one from Iowa State University, have shown that pavement using RAS alone or in combination with other materials and technologies can be successful and meet state agency quality assurance requirements if used in the right proportions.
The FHWA recommends state transportation departments follow the 5 percent maximum guideline so contractors can prevent cracking without drastically altering the composition of their existing mixes. Some local agencies have additional guidelines of their own regarding the use of RAS. In some states, for example, the local agencies require hot mix asphalt producers to use performance-grade blending charts to properly design the mix.
A case study by the Illinois State Toll Highway Authority found the price savings with RAS varies depending on the asphalt mix but can be anywhere between $5 and $15 per ton. But around the same time cracking concerns arose, asphalt cement prices began to sink, making the cost differential negligible for some.
And, contrary to RAS, asphalt pavement is the most recycled product in the country, according to the National Asphalt Pavement Association. The ease of recovering recycled asphalt pavement (RAP) contributed to additional stress on the RAS market.
Between cracking concerns and more attractive alternatives, contractors began ditching recycled shingles in favor of virgin cement asphalt, and many haven’t looked back.
Heading into 2019, asphalt cement prices and education efforts around proper hot asphalt mix concentrations have both been on the rise, spurring a new bout of optimism for weary shingle recyclers.
Horton and Clarke have managed to retain their optimism, though, through their work developing new end markets. Horton’s latest patent, currently pending approval, establishes a way to manufacture briquettes, pellets and shapes through densification of recycled asphaltic limestone powder, which can be extracted from shingles through his patented processing methods.
The end products have several potential uses. Stand-alone asphaltic pellets can be introduced to paving manufacturers’ design mixes and roofing manufacturers’ coating mixes, or they can be used as binders for the biomass market. The pellets and briquettes can also be used as waterproof energy sources either on their own or combined with other sources.
While the energy put out by asphaltic limestone is not nearly as much as coal, “it competes well with wood and it’s a decent product for cement plants,” Horton says.
“Paving was the predominant use once upon a time, but we believe there are other markets out there that can use our product and can rebirth the industry,” Clarke says.
Horton’s dream when he started ASR Systems a decade ago was to develop a shingle-to-shingle market, creating the first circular economy for asphalt.
That dream is still distant, though not abandoned. Horton says recycling shingles to create new ones poses significant challenges that ASR is still working on tackling. “The solution for shingles to shingles is an initiative that has not been fruitful over the past 10 years that we’ve been in business … but that doesn’t stop the drive to find a solution,” Horton says.
In the meantime, ASR is pursuing new end markets, honing its processing capabilities and working to create an upturn in the industry instead of waiting for it to happen.
“I see a significant industry change on the horizon,” Horton says. “When you have a downturn in one part of the industry, the industry is forced to find new solutions. What else do you do?”
This article originally appeared in the July-August issue of Construction & Demolition Recycling. The author is the assistant editor of Construction & Demolition Recycling magazine and can be contacted at firstname.lastname@example.org.