The National Academies of Sciences, Engineering, and Medicine (NASEM) sponsored a white paper in which Stanford engineers Michael Lepech and Zhiye Li investigate the present state of plastic recycling in a circular economy, its challenges, and requirements. They also look into its lasting durability and environmental impact, especially in infrastructure. Using computer models, research, field experiments, and feedback from recycling professionals, they study real-life examples: turning plastic waste into façade panels at the San Francisco Museum of Modern Art and using it for pavement in a California transportation project.
Lepech believes using recycled plastic for infrastructure can be groundbreaking. He suggests its consistent nature might simplify its reuse in infrastructure. But, challenges exist. Making infrastructure from plastic waste is more complicated. “One of the challenges that we and others identified through this work is the difficult economics and logistics of managing plastic waste streams from municipal solid waste,” he says in an interview with Stanford News. “Plastic waste material flow is highly variable. Its mass can change from month to month, as can the type of plastic – lots of different packaging, for example.”
Stanford’s research shows potential in repurposing plastics for infrastructure if they meet performance standards and are environmentally better than traditional materials. They studied plastic waste usage in buildings and roads. The San Francisco Museum of Modern Art features a fiberglass-reinforced plastic facade, the most significant architectural use in the US so far. Additionally, in 2020, a part of California’s Highway 162 was paved with recycled asphalt and liquid plastic from single-use bottles, marking a debut in 100% recycled road materials.
These examples inspire Michael and Zhiye’s research on plastic waste’s potential for infrastructure. Li warns that not all plastics are suitable for long-term use or infrastructure integration. “Over 60% of recycled plastic is for packaging, which has a short lifespan. Car parts may use recycled plastic, but they don’t need much,” she points out.
Despite these challenges, there are benefits, like reducing environmental risks and cutting insurance costs. Lepech emphasizes the growth potential for businesses focusing on green solutions. “Companies gain clarity when their values align with their mission, particularly if they’re eco-friendly,” he adds.
This news has been written in collaboration with Chat GPT-4