Digital Mix Design for Performance Optimization of Asphalt Concrete

本项目的目标是利用建模和模拟方法了解沥青混凝土的基本变形和破坏机理，从而设计出具有较好的抗车辙、疲劳和温度裂缝能力的性能更好的混合料，并将配合比设计融入路面结构设计。利用先进的X射线层析成像技术无损地表征集料颗粒的三维表示(数字颗粒)，基于最大化颗粒接触和荷载传递均匀度的高性能计算选择一组数字颗粒来选择最佳级配，以及国家自然科学基金项目沥青混凝土S抗永久变形、疲劳和热裂性能评价项目开发的数字样品和数字试验技术。这些创新对设计长效混合料产生了巨大的潜在影响，并更准确地预测了这些混合料在真实道路条件下的行为，从而延长了路面寿命，降低了生命周期成本。沥青铺装行业直接和间接雇用了约90万人。设计和施工长寿命沥青混凝土路面对节约有限的自然资源和经济资源具有重要意义。该项目还将把基本机构识别、模拟和可视化整合到下一代工程师的实际使用和教学中。此外，该项目将与现有的弗吉尼亚理工大学交通运输学院S K-12项目相结合，让这些参与者在参观期间拥有执行传统混合料设计和数字混合料设计的实践经验。在该项目的最后一年，将管理一个面向本科生的小型研究体验(REU)计划，让本科生，特别是那些少数族裔和代表性不足的学生接触到先进技术，并吸引他们进入科学和工程专业的研究生学习。

The objective of this project is to use modeling and simulation methods to understand the fundamental deformation and failure mechanisms of asphalt concrete, which will lead to designing better performing mixes of balanced capability against rutting, fatigue and thermal cracking; and integration of mix design into pavement structure design. It will be achieved though making use of advanced x-ray computed tomography to no-destructively characterize the three-dimensional representations of aggregate particles (Digital Particle), high performance computing to select an optimum gradation through packing a set of digital particles based on maximizing the particle contacts and loading transfer uniformity, and the digital specimen and digital test techniques developed through a previous project supported by the National Science Foundation to evaluate asphalt concrete?s resistance against permanent deformation, fatigue and thermal cracking. These innovations have great potential impact on designing long-lasting mixes, and more accurate predictions of the behavior of these mixes under real road conditions, leading to extended pavement life and reduced life cycle cost.Asphalt paving industries directly and indirectly employ about 900,000 people. Designing and constructing long-lasting asphalt concrete pavements have significant impacts on saving limited natural and economic resources. The project will also integrate fundamental mechanism identification, simulation and visualization into both practical use and teaching of next generation engineers. In addition, the project will tie into an existing Virginia Tech Transportation Institute?s K-12 program to allow these participants have hands-on experience on performing both traditional mix design and digital mix design during their visit. A mini Research Experience for Undergraduate (REU) program will be managed during the last year of the project to expose the undergraduate students, especially those of minority and underrepresented to the advanced technology and attract them to graduate study in science and engineering.