This project is to engineer sustainable alternatives to petroleum-based adhesives for use in construction and pavement. The research objective of the project is to test the hypothesis that introducing bio-binder to asphalt binder can change the phase structure within asphalt binder to produce bio-modified binder (BMB) with desired rheological and surface characteristics. Desired characteristics are an increase in BMB's adhesion strength and stress release rate, and a reduction of its viscosity at corresponding temperatures. This in turn can improve pavement sustainability in several ways: 1) an increase in adhesion strength between binder and aggregate can reduce moisture damage in pavement, 2) an increase in binder's stress release rate can reduce low temperature cracking in pavement, and 3) a reduction in binder viscosity can facilitate use of reclaimed asphalt pavement and recycled asphalt shingles in paving mixtures. It is hypothesized that when bio-binder is added to the asphalt binder, bio-binder molecules penetrate into the asphalt binder's matrix changing its chain conformation and molecular packing. The interchain interactions between the long alkyl chains of the bio-binder and those of the asphalt molecules' side chains hinder the stacking of the aromatic cores of the asphalt molecules improving asphalt's properties. Molecular dynamics simulations will be implemented to study how the two materials interact and how their interactions impact rheology, aging and adhesion characteristics of the bio-modified binder.
This project opens a new paradigm in asphalt material characterization and modeling, enabling an integration of chemistry and mechanics while enhancing pavement sustainability and revolutionizing waste management practices for better environmental protection. It will offer a simultaneous approach to sequester carbon and address problems associated with manure management while improving pavement sustainability and enhancing U.S. economic competiveness by reducing dependence on petroleum resources. The broader impact of the project will be further expanded by reaching audiences ranging from university educators to industry practitioners, farmers and K-12 deaf students to achieve educational goal of the project including 1) enhancing students' knowledge in the area of sustainable pavement and 2) providing professionals and decision makers with the scientific rationale underlying the use of bio-binder.
National Science Foundation, Division of Civil, Mechanical, and Manufacturing Innovation