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.