Spotlight: Paving the Way With Recycled Plastics in the State of Hawai‘i

In the state of Hawai‘i, our collaborators are building asphalt roads with recycled plastics. It’s part of a sustainable transportation initiative.

NIST is collaborating with the Hawai‘i Department of Transportation, Center for Marine Debris Research and University of Hawai‘i on the project. The pilot roadway was completed last fall and is now undergoing testing to see if any plastic particles are leaching out from the roadway. 

The pilot test road is split into three different sections: 

• Traditional asphalt pavement that contains a polymer-modified binder, a product that cements everything together. 
• Asphalt pavement with recycled plastics taken from plastic waste and converted into pellets and the traditional polymer-modified binder. 
• Asphalt pavement with plastic pellets, plus a binder that’s different from the type in traditional asphalt in Hawai‘i. 

NIST biologist Jennifer Lynch, along with students from Hawai‘i Pacific University, is analyzing water samples taken from the test road to check for any plastic additives or other chemicals that may leach from the road and have negative effects on the environment. A separate group with the University of Hawai‘i is performing mechanical testing of the pilot road to make sure it holds up to traffic and weather conditions. 

All samples have been collected but are still being analyzed. Future projects may include building another test road with plastics taken from derelict fishing nets and other gear removed from the ocean and Hawai‘i shorelines. Stay tuned for the final results!