A team of researchers from Arizona State University has created an alternative for asphalt binder — used in the construction of roadways, playgrounds, bicycle paths, running tracks, tennis and basketball courts, and more — that reduces the release of toxic fumes from asphalt-surfaced areas.

As an alternative to bitumen, which is commonly used as the binding material in asphalt, AirDuo’s AP1 paving mixture is comprised of low-carbon, bio-based materials that are reportedly less toxic than bitumen and that also serve as a toxicity filter.

Source: Arizona State University

According to the researchers, once the traditional blend of aggregates and binder is layered on roadways, stress from factors such as heat, sun, weather and traffic cause the release of products that can be highly toxic.

As such, the Arizona State team developed AirDuo using biomass waste from forest residue. According to the researchers, AirDuo’s AP1 demonstrated a roughly 70% reduction in emissions in the lab, thereby illustrating toxic fume reduction.

"We are using biomass as our feedstock — it has already pulled CO₂ from the air prior to harvesting. The AP1 helps create a sustainable built environment and provides reduced health risks to both asphalt workers and those using asphalt-surfaced areas," the team of researchers explained.

AirDuo is detailed in the article, Bio-Carbon as a Means of Carbon Management in Roads, which appears in the journal Advanced Sustainable Systems.