Producing a Sustainable, Bio-Based Alternative to Petroleum-Based Asphalt Binder

TRB's National Cooperative Highway Research Program (NCHRP) Innovations Deserving Exploratory Analysis (IDEA) Report 171: Producing a Sustainable, Bio-Based Alternative to Petroleum-Based Asphalt Binder explores adding bio-binder to crumb-rubber-modified (CRM) asphalt to enhance its low-temperature rheological properties while improving workability and reducing phase separation. The application of rubber in asphalt may enhance performance of asphalt mixture in a wide range of service temperatures: improved rutting resistance at high temperature, increased fatigue resistance at intermediate service temperature, and enhanced stress relaxation properties at low temperature. The report investigates the application of a bio-binder (an amide-based modifier made from thermochemical conversion of swine manure) to facilitate the dissolution of rubber polymers by facilitating the breakage of disulfide bonds in rubber polymers while improving workability and rheological properties.