Transforming Plastic Waste into Asphalt:
Paving the Way for Sustainable Roads

With the holiday season upon us, many of us in the US are gearing up to travel to be with friends and family, a reality that was impossible for most of us last year. While many travelers are considering ticket prices and COVID guidelines when deciding how to reach their holiday destinations, the climate impacts of these journeys should also cross our minds — given that transportation is the largest contributor to the GHG emissions in the US, accounting for around 29 percent of total emissions in 2019.

While that number refers primarily to the emissions from the cars, trucks, trains and planes that carry people and products across the nation, the roads on which much of this movement occurs present another key player in the push toward more sustainable transportation. The asphalt used to pave these roads presents a major source of air pollution, with Yale researchers asserting that finding ways to make roads more environmentally friendly is just as important as doing the same for cars and trucks.

Companies such as Dow are working to do just that through technology for the production of recycled polymer modified asphalt (RPMA), which transforms plastic waste into durable asphalt for roads and parking lots. Midwest retail giant Meijer’s recent adoption of this technology for the parking lot of its Holland, Michigan location offers a clear case study of the potential asphalt has to carry us toward a more sustainable and circular future.

Circularity in action

Meijer, one of the largest retailers in the US and a staple for families across the Midwest, has long been a conduit for more sustainable and circular practices in the communities it serves. Since 2014, Meijer has offered a store drop-off recycling program in each of its locations for customers to correctly recycle plastic films — such as bread, dry cleaning, and single-use shopping bags — that most curbside recycling services are unable to process and therefore end up in landfills. This year, Meijer anticipates that this program will recycle six million pounds of plastics.

Image credit: Meijer

Meijer’s recent collaboration with Dow takes these efforts a step further by giving that plastic waste a new purpose: All of the recycled plastic used to produce the new parking lot, approximately 12,500 pounds of post-consumer recycled plastic (PCR) —equivalent to 944,000 plastic grocery bags — was collected through the recycling program. These bags, at one point considered waste, have now been given new, sustainable value and functionality.

A case study in collaboration

The process to turn these plastic bags into sustainable and durable asphalt had many phases and many partners. First, the plastics recycled by residents and collected by Meijer were converted into usable PCR content by PADNOS, a Michigan-based materials recycler. Second, asphalt emulsion company K-Tech Specialty Coatings utilized Dow’s technological expertise to bind the base asphalt with the PCR content. Construction contractor Rieth-Riley then produced the final hot-mix asphalt and paved the new parking lot.

This level of collaboration is key to unlocking these kinds of sustainable and circular solutions that are necessary to close the loop on waste. Pooling together the expertise and skills of these teams allowed for the creation of the best possible product. For example, in 2017, Dow embarked on a partnership with the government of Indonesia to reduce plastic waste in the ocean by 70 percent by 2025, utilizing this technology; and in August of this year helped create an RMPA parking lot at the University of Missouri. These partnerships are allowing us to create functional, sustainable and valuable new lifecycles for plastic waste.

Paving the way for more sustainable roads

In order for truly sustainable and circular systems to be realized, every facet of normal life must be re-considered — from the cars we drive to the roads we drive them on. While the majority of roads we take to reach our families and friends this holiday season will not be paved with recycled polymer modified asphalt, the success of projects such as the Meijer parking lot are driving us closer to this more sustainable, circular path forward.