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

摘要石基基础设施材料，包括波特兰水泥混凝土、沥青混凝土和人类增强的土壤，构成了物质基础设施的核心，支撑着人类在各个领域取得的成就。石基材料的结构相似，由骨料(或石材)骨架、粘结介质、填充物和空隙组成。由于结合介质不同，土、沥青混凝土和水泥混凝土的性能有很大的不同，但由于骨料骨架结构的共性，这些材料可以表现出相似的行为。在过去的几年里，X射线计算机层析成像、离散和连续建模技术、基于纳米力学的有限元和离散元方法以及高性能计算等实验表征技术的发展使得计算机模拟石材的行为而不是仅仅依赖于实验表征，从而节省了巨大的设备、材料和人力成本。有了这些进展，石材材料的研究可以统一在实验、建模和计算机模拟三个方面。拟议研究的目标是开发这一统一的方法，重点是(A)开发一个健壮的框架，用于在从纳米到厘米的多个尺度上表征石材基础设施的三维微结构；(B)集成离散和连续建模技术；(C)计算材料特性；以及(D)通过弗吉尼亚理工学院和美国国家标准与技术研究所(NIST)的伙伴关系和合作努力，使用材料行为模拟以统一的方式设计更好的石材基础设施材料。这一伙伴关系将共享资源、想法和设施。NIST的科学家可以将他们的研究扩展到联邦公路管理局感兴趣的沥青材料领域；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.