Repurposed Waste-Made Roads

Researchers at the Hawaiʻi Pacific University’s Center for Marine Debris Research are collaborating with the Hawaii Department of Transportation to evaluate the use of recovered plastic waste as a component in asphalt.

Working alongside industry partners, the team tested three pavement formulations on a residential road: conventional polymer-modified asphalt, asphalt incorporating recycled polyethylene from household waste, and a variant using polyethylene derived from fishing nets. The test sections remained in active use for approximately 11 months.

Using advanced analytical techniques, the team examined whether plastic-modified asphalt contributes to microplastic release. Ongoing studies are focused on long-term performance to determine whether the approach can be scaled beyond pilot applications.

“This work investigates whether it’s responsible to use recycled plastics in Hawaii’s roads,” said Jeremy Axworthy, a researcher involved in the project. “By reusing plastic waste that is already in Hawaii, we can reduce the environmental and economic impacts of transporting waste plastics from the islands, incinerating it or dumping it in Hawaii’s overflowing landfills.”

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