Secondary Materials in Asphalt Mixtures

These Guidelines provide a structured, five-step framework for evaluating secondary materials, industrial by-products, recyclables, and waste derived materials, as substitutes for conventional aggregates, binders, or fillers in asphalt mixtures. The framework is designed to capture cost, performance, and sustainability benefits without compromising worker safety, environmental protection, pavement durability, or long-term value, and to help contractors, suppliers, and agencies decide whether and how a candidate material should advance from trial to specification.

Part A consists of the secondary materials evaluation framework, providing guidelines and reference tools for contractors, suppliers, and agencies.

Part B presents a five-step, stakeholder-centric evaluation applied to dry-process rPE modification of HMA.