CAREER: Integrated Research and Education to Improve Pavement Sustainability Using Bio-Binder

该学院早期职业发展（Career）项目旨在设计用于建筑和路面的石油基粘合剂的可持续替代品。该项目的研究目的是验证在沥青粘结剂中引入生物粘结剂可以改变沥青粘结剂内部的相结构，从而生产出具有理想流变性和表面特性的生物改性粘结剂（BMB）的假设。期望的特性是增加BMB的粘附强度和应力释放速率，并在相应温度下降低其粘度。这反过来又可以从几个方面提高路面的可持续性：1)增加粘结剂和骨料之间的粘结强度可以减少路面的水分损害，2)增加粘结剂的应力释放率可以减少路面的低温开裂，3)降低粘结剂粘度可以促进再生沥青路面和再生沥青瓦在路面混合物中的使用。假设当生物粘合剂加入到沥青粘合剂中时，生物粘合剂分子会渗透到沥青粘合剂的基质中，改变其链构象和分子排列。生物粘合剂的长烷基链与沥青分子侧链之间的链间相互作用阻碍了沥青分子芳香核的堆积，从而改善了沥青的性能。分子动力学模拟将研究两种材料如何相互作用，以及它们的相互作用如何影响生物改性粘合剂的流变学、老化和粘附特性。该项目开辟了沥青材料表征和建模的新范式，实现了化学和力学的结合，同时提高了路面的可持续性，并彻底改变了废物管理实践，以更好地保护环境。它将同时提供固碳和解决粪便管理相关问题的方法，同时提高路面的可持续性，并通过减少对石油资源的依赖来增强美国的经济竞争力。该项目的影响范围将进一步扩大，从大学教育工作者到行业从业者、农民和K-12聋哑学生，以实现该项目的教育目标，包括1)提高学生在可持续路面领域的知识，2)为专业人士和决策者提供使用生物粘合剂的科学依据。

This Faculty Early Career Development (CAREER) 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.