Executive Summary
Tire-derived aggregate (TDA) offers a sustainable solution for addressing the environmental challenges posed by the approximately 330 million tires discarded annually in the U.S. and Canada. TDA, produced by repurposing end-of-life tires, serves as a viable alternative to traditional aggregates in civil and environmental engineering. However, its usage remains limited in construction projects over the past decade, signalling a significant opportunity for expansion.
TDA presents unique engineering properties, such as lightweight composition, high porosity, vibration mitigation, and thermal insulation, making it suitable for diverse applications like drainage systems, noise barriers, and road construction. Additionally, TDA’s high shear strength and permeability, coupled with freeze-thaw mitigation, reduce lateral loads and enhance drainage performance. Research confirms TDA’s cost-effectiveness and sustainability, offering consistent material quality and reducing the environmental impact associated with natural aggregate extraction and greenhouse gas emissions.
Environmental studies on TDA demonstrate its safety in engineering applications, showing that while metals and synthetic organic compounds may leach from TDA, their concentrations remain below regulatory thresholds. Furthermore, these leached substances are quickly immobilized by the soil matrix, reducing risks to aquatic life and ecosystems. TDA also acts as a contaminant cleaner, interacting with metals like iron and zinc to precipitate or adsorb pollutants, further mitigating environmental concerns.
In conclusion, TDA not only supports sustainable construction by lowering costs and promoting recycling but also aligns with circular economy principles by minimizing waste and emissions. Expanding TDA use in infrastructure projects will enhance environmental performance, reduce reliance on natural aggregates, and unlock further engineering benefits through innovative applications.