CAREER: Investigating Molecular, Physical and Mechanical Properties that Influence Macroscopic Self-Healing in Asphalt Materials

这项教师早期职业发展（Career）计划的目标是寻找和建立沥青粘合剂的化学和机械特性与其固有的逆转微裂缝和自愈能力之间的关系。这将通过推进、验证和整合描述裂纹润湿的接触力学理论，以及描述强度增加的粘附和相互扩散理论来实现。新的实验工具可以在纳米尺度上实时测量裂纹的打开和关闭，并将用于本研究。该奖项的教育部分将开发一个电子学习模块，该模块将使用简单，简短的示例和案例研究来暴露，教育和激励本科生调查和理解土木工程应用中使用的材料的基本化学和机械性能的宏观行为与其宏观行为之间的联系。本研究的实验工具和理论发现将促进对粘弹性材料（如用于建造路面的聚合物和沥青粘合剂）中微裂纹生长和自愈的理解。纳税人每年花费数十亿美元来扩大和维护我们的路面基础设施。这项研究的发现也将为设计具有优异自愈特性和机械性能的沥青粘合剂和混合物提供急需的基础知识。这些工程粘合剂的使用将显著提高路面的使用寿命，并最终减少不可再生自然资源的消耗，如原油和破碎的矿物集料。

The objective of this Faculty Early Career Development (CAREER) Program award is to seek and establish the relationship between the chemical and mechanical properties of asphalt binder and its inherent ability to reverse micro-cracks and self-heal. This will be achieved by advancing, verifying and integrating the theories of contact mechanics that describe crack wetting, and theories of adhesion and inter-diffusion that describe strength gain. Novel experimental tools that allow measurement of crack opening and closing in real time at the nanometer scale will be fabricated and used in this research. The educational component of this award will develop an e-learning module that will use simple, short examples and case studies to expose, educate, and inspire undergraduate students to investigate and understand the link between the macroscopic behavior of fundamental chemical and mechanical properties of materials used in civil engineering applications to their macroscopic behavior.The experimental tools and theoretical findings from this research will advance the understanding of micro-crack growth and self-healing in viscoelastic materials such as polymers and asphalt binders that are used to construct pavements. Billions of taxpayer dollars are spent annually to expand and maintain our pavement infrastructure. The findings from this research will also provide much needed fundamental knowledge to design asphalt binders and mixtures with superior self-healing characteristics and mechanical properties. The use of these engineered binders will significantly improve the serviceable life of pavements and ultimately reduce consumption of non-renewable natural resources such as crude oil and crushed mineral aggregates.