Chemo-Mechanical Multiscale Characterization of Asphalt Materials

Michael Elwardany, Ph.D., P.E.

The world’s economic growth and environmental sustainability depend on the durability and resilience of its transportation infrastructure. Asphalt pavements represent about 94 percent of paved roads in the U.S. The formulation of paving asphalts has changed considerably due to various economic, technical, and environmental reasons. Asphalt modification with polymers and various additives continued to grow. Warm mix technologies and rejuvenators are becoming more common as recycling of higher quantities of old pavements and roofing shingles is receiving attention to achieve net zero carbon emission goals by 2050. Moreover, recycling other industrial wastes, such as ground tire rubber and recycled plastics in asphalt paving materials is receiving more attention nowadays. Some of these changes led to incompatible binders and oxidative aging-susceptible materials, which leads to stiff and brittle materials that are prone to cracking and surface distress. As a result, state highway agencies are increasingly experiencing premature failures of newly constructed pavements despite general compliance with existing material specifications, mix, pavement design standards, and construction methods. This presentation will focus on the various diagnostic techniques for refining processes, waxes, polymers, and recycled materials in asphalt material formulation. These techniques include chemical, microstructural, thermal, rheological, and mechanical characterization methods. Additionally, some of these chemo-mechanical models are being integrated with viscoelastic continuum damage material modeling into next-generation pavement structural analysis and design tools. These research outcomes provide bases to improve binder formulation, mixture design, and pavement analysis to save taxpayers money and achieve more sustainable and resilient transportation infrastructure.

Dr. Michael Elwardany is an Assistant Professor at the FAMU-FSU College of Engineering. Before joining Florida State University, he was the manager of the Asphalt Binder and Mixture Laboratories at the Federal Highway Administration - Turner-Fairbank Highway Research Center. He earned his Ph.D. from NCSU with a focus on the multiscale characterization, laboratory simulation, and modeling of long-term aging in asphalt pavements. He was the program manager for paving asphalts at the Western Research Institute for three years. Dr. Elwardany served as the principal investigator or project manager to a National Cooperative Highway Research Program Project, a USDOT Small Business Innovation Research Project, and the Asphalt Industry Research Consortium. He is the original developer of the Aging Duration Maps, the internal restraint damage mechanism model, and a couple of binder rheological and failure parameters. His work was published in 24 journal papers, 30 conference papers, and 7 final project reports.