A first of its kind road-building project in the U.S. that Dow Inc. hired a Mt. Pleasant’s company to take on could lead to an environmentally positive innovation for the future of the asphalt industry in the U.S.
In early 2019, Dow Inc.
paved the first road in its facility in Freeport, Texas using modified asphalt mix containing recycled plastic. The paving was part of a field demonstration project using an ELVALOY(™)RET polymer technology.
The Freeport project quickly caught the attention of the Midland County Road Commission
(MCRC), who invited Dow to test the product on local roads that were due for repair. Four public roads were selected for the project with recycled plastic modified asphalt - a first for the United States, which had until this point seen similar projects confined to private roads and parking lots.
“It was neat to be on the forefront of something new,” says Art Buck, Superintendent of MCRC. “Everybody knows that the disposal of plastics is a big issue, so if we can find another good use for them, we’re doing our jobs.”
The roads that MCRC chose were Badour Road in Bullock Creek and Mid-Bay County Road, Waskevich Lane, and Julie Ann Drive in Larkin Township.
Dow and MCRC brought in Central Asphalt
, a Fisher family-owned business located in Mt. Pleasant, Michigan, to pave public roads and parking lots around the Midland area with the modified asphalt mix that incorporated #2 and #4 plastic waste from one of Dow’s clients.
The collaboration kicked off in a way that Buck and Aaron White, Vice President of Central Asphalt, both described as a “roundabout way,” with each group sharing its connections, resources, and information to bring the project together.
Central Asphalt’s paving crew placing the modified asphalt mix containing recycled plastic over Waskevich Lane in Larkin Township.
“We put them in touch with a few suppliers to work with them on blending their plastics and then we took the chance and ran it through our plant,” says White.
Sharon Goudie, Senior Market Development Manager at Dow, says that when they first met with Central Asphalt they had reasonable concerns about how the recycled plastic modified binder would process their equipment.
“These are million-dollar operations and there is always a concern about introducing an unknown product into equipment they were not familiar with or had never run before,” says Goudie. “After meeting with Central Asphalt’s Aaron White and educating his team on how to handle the material, Central was willing to proceed with the project.”
Dow worked with K-Tech Specialty Coatings, Inc.
from Ashley, Indiana, to produce the recycled plastic modified binder that was delivered to the Central Asphalt team.
“We didn’t see any difference in performance. It constructed itself just like it would if it was a regular pavement,” says White. “It went through our plant fine, it was fine in our trucks, we didn’t have any problems getting it through our equipment.”
Between the Midland and Freeport projects, Dow Inc. reported using a total of 12,000 lbs. of recycled plastics, equivalent to the weight of 890,000 grocery bags.
Beyond diverting recycled materials away from landfills, Goudie says there are other benefits to roads modified with recycled plastics. It reduces the energy output required to make new, or virgin, plastics and it can have an overarching impact on the amount of H2 emissions that come off asphalt plants.
Dow’s ELVALOY™RET polymer, a 30-year-old product Dow acquired after its merger with DuPont in 2017, is a reactive terpolymer that reacts with the asphaltenes in the binder, allowing it to act as a compatibilizer for polyethylene-rich recycled plastic. After the merger, the company set its researcher to task finding new uses for its products to meet its sustainability goals
, which led to identifying its use as a compatibilizer for #2 and #4 plastic waste as a modifier for asphalt.
The polymer solves a longstanding problem that the asphalt industry has encountered since the first attempts at using recycled plastics in roads, namely how plastic separates once it's melted into the hot asphalt.
Goudie says early attempts to make roads that incorporated recycled plastic failed because of this separation. The plastic melted into the hot asphalt without blending or bonding with the material. The result of these efforts was crumbling roads, which led some in the asphalt industry to be skeptical about the use of recycled plastic in paving.
“We (Dow) are still fighting that perception today,” says Goudie. “We are continuing to demonstrate its viability and performance through field projects across the U.S. and globally to collect field data to change the industry’s perception.”
Photo courtesy of Central Asphalt.
White says Central Asphalt wouldn’t hesitate to pave recycled roads again.
“Everyone is trying to be as green as they can,” says White, “Asphalt paving sometimes gets a rep for the asphalt plants, with visions of these big stacks of dust and dirt. What they don’t see in the long run is the work we do to be good stewards of the environment.”
The first mix of modified asphalt for the Michigan project was poured in August 2019 and finished over the course of a few days. Today, the roads provide Dow with valuable data the company intends on using to convince state road authorities to include ELVALOY™RET as an approved material for road construction.
Despite being public roads, the roads paved during the project were not funded by the Michigan Department of Transportation
(M-DOT), the governmental entity that regularly supports local government’s road construction and maintenance. Instead, funding came from the Michigan Department of Environmental Quality and other sources like the MCRC and Dow.
“Because they are local roads, there was local funding involved,” says Buck. “Any additional cost was picked up by Dow, so it didn’t cost us any more to do than it would if this product hadn’t been involved.”
Dow is currently working with M-DOT and other state road authorities to gain approval for its product, which is a process that takes several years.
According to Goudie, the use of ELVALOY(™)RET with recycled plastic does not require DOTs to revise their performance-graded asphalt specifications. Dow’s technology can meet the existing specifications.
State approval of Dow’s product would allow a state’s department of transportation to fund road projects, with the polymer leading to more widespread use. The solution could replace products more harmful to the environment that are currently used by the asphalt industry.
“In August, this will be two years that these roads have been paved,” says Goudie, “These roads have endured two winters now, and they are performing well.”