Unified Approach for Multiscale Characterization, Modeling, and Simulation for Stone-based Infrastructure Materials

基于石材的基础设施材料，包括波特兰水泥混凝土、沥青混凝土和人工增强土壤，形成了支撑人类在每个竞技场取得成就的物理基础设施的核心。石基材料的结构相似，由骨料（或石）骨架、粘结介质、填料和空隙组成。由于不同的粘结介质，土壤、沥青混凝土和水泥混凝土具有显著不同的性质;然而，由于共同的骨料骨架结构，这些材料可以表现出相似的行为。在过去的几年里，实验表征技术的发展，如X射线计算机断层扫描，离散和连续建模技术，基于纳米力学的有限元（有限元法）和DEM（离散单元法）和高性能计算已经允许计算机模拟石基材料的行为，而不是仅仅依赖于实验表征，从而节省了设备的巨大成本，材料和人力。这些进展使石基材料的研究可以统一在实验、建模和计算机模拟中。拟议研究的目标是开发这种统一的方法，重点是（a）开发一个强大的框架，用于在从纳米到厘米的多尺度上表征基于石材的基础设施的3-D微观结构;（B）集成离散和连续建模技术;（c）计算材料特性;以及（d）使用材料行为的模拟来设计更好的石材-通过弗吉尼亚理工大学和美国国家基础设施研究所的研究人员的合作和协作，标准与技术（NIST）。该伙伴关系将分享资源、想法和设施。NIST科学家可以将他们的研究扩展到沥青材料，这是联邦公路管理局感兴趣的;弗吉尼亚理工大学的研究人员可以将NIST科学家开创的计算材料科学技术应用于他们对石材材料的研究和教育。

Abstract Stone-based infrastructure materials, including Portland cement concrete, asphalt concrete, and human augmented soils, form the core of the physical infrastructure that underpins humanity's accomplishments in every arena. Stone-based materials are similar in their structure, which consists of an aggregate (or stone) skeleton, a binding medium, fillers, and air voids. Due to different binding media, soil, asphalt concrete and cement concrete have significantly different properties; however, due to the common aggregate skeleton structure, these materials can demonstrate similar behavior. In the last few years, developments in experimental characterization techniques such as X-ray Computed Tomography, discrete and continuum modeling techniques, nanomechanics-based FEM (Finite Element Method) and DEM (Discrete Element Method), and high performance computing have allowed the computer simulation of the behavior of stone-based materials instead of relying solely on experimental characterization, thus saving tremendous costs in equipment, materials and manpower. With these advances, research in stone-based materials can be unified in experimentation, modeling and computer simulation. The goal of the proposed research is to develop this unified approach, focusing on (a) developing a robust framework for characterizing the 3-D microstructure of stone-based infrastructure at multiscales from nano to centimeter; (b) integrating discrete and continuum modeling techniques; (c) computing material properties; and (d) using simulations of material behavior to design better stone-based infrastructure materials in a unified manner through partnership and collaborative efforts of researchers at Virginia Tech and the National Institute of Standards and Technology (NIST). The partnership will share resources, ideas and facilities. NIST scientists can extend their research into asphaltic materials, which are of interest to the Federal Highway Administration; and Virginia Tech researchers can adapt the use of computational materials science techniques pioneered by NIST scientists to their research and education on stone-based materials.