Paving roads with recycled plastics: Microplastic pollution or eco-friendly solution?

Area of Science:

• Environmental Science
• Materials Science
• Polymer Science

Background:

• Plastic-modified roads offer a sustainable solution for plastic waste and improved pavement performance.
• The environmental impact of microplastic release from these roads remains largely unquantified.

Purpose of the Study:

• To develop and validate a novel laboratory abrasion procedure for quantifying microplastic release from recycled plastic-modified asphalt.
• To investigate the influence of environmental factors, plastic type/content, and incorporation methods on microplastic generation.

Main Methods:

• Utilized a Wet Track Abrasion machine to simulate road traffic abrasion.
• Developed a new microplastic extraction protocol to analyze released particles.
• Assessed microplastic generation under varying temperature and pH conditions.

Main Results:

• Recycled plastic incorporated into the bitumen matrix showed earlier microplastic release compared to aggregate substitution.
• Cold temperatures and low pH significantly increased microplastic generation.
• The study established a reliable laboratory method for assessing microplastic release.

Conclusions:

• The developed abrasion and extraction procedure provides a valuable tool for environmental agencies and authorities.
• This method can inform policies and practices for the sustainable use of recycled plastics in road construction.
• Understanding microplastic release is crucial for mitigating environmental risks associated with plastic-modified roads.