Development of Concrete Damage-Flow Rate Correlation using Integrated Structural Testing and X-Ray Tomography

项目摘要使用集成结构测试和X射线断层扫描开发混凝土损伤-流速相关性Tara C.哈钦森（PI）1和Falko Kuester 2混凝土是迄今为止在美国使用最广泛的建筑材料，广泛用于我国建筑、高速公路、隧道、供水和污水系统以及其他基础设施的建设。混凝土的使用寿命对它的运输性能的强烈依赖性意味着调查，这是面向研究这种内部微观结构，应将这些运输性能的混凝土组件的损坏状态。在这个建议中，我们试图推进我们的基本知识的钢筋混凝土构件的损坏特性，并将这些特性与一个基本的运输属性。虽然许多运输机制肯定是感兴趣的，我们选择的空气渗透率作为感兴趣的运输机制，作为迈向其他机制的第一步，并奠定基础的方法提出。我们所提出的方法包括集成结构测试的比例标本，X射线计算机断层扫描（CT）成像，和空气流量实验的20个模型钢筋混凝土面板式标本。试样经受单轴和双轴加载条件，并且包括几何形状（纵横比和面板厚度）、材料细节（钢筋比率和混凝土强度）和加载细节（轴向载荷和加载协议）的参数变化。数值评估的渗透性和泄漏率公式在文献中，以及有限元模拟的实验标本，将进行全面努力，发展设计指导有关的损坏泄漏率相关的钢筋混凝土元件。智力优点-智力优点，这包括发展的实验方法和结果，在钢筋混凝土的损伤运输关系的理解的根本进步，并对设计行业的实际影响。从这项工作中获得的数据集（图像和数值数据）将刺激对这种复杂复合材料的内部损伤分布的新发现。最终，这项工作将导致设计指导，这是混凝土渗透性下降的原因。混凝土研究的整体进展将导致新基础设施和现有结构修复成本的降低，同时延长我们使用最广泛的建筑材料之一的使用寿命。更广泛的影响-更广泛的技术影响包括我们对混凝土作为基本建筑材料的理解的进步，从而导致改进的设计，具有更可靠的性质估计和性能估计。X射线CT系统的获得和实施将对加州大学欧文分校的研究活动产生深远的影响，对学生和教师以及对使用该系统感兴趣的当地学术界都有影响。数据，图像和数字数据的教育影响，为接触所有感兴趣的学生提供了一个自然的避风港，从公众到K-12，特别是多样化和/或少数民族学生。这些作品的自然数字性质使其在互联网上传播是可行的，我们计划设计一个专门的网站（我们称之为ConcretePedia），专门用于传播这些VRML格式的图像数据集（供公众交互式地查看和学习）。这项工作还积极参与工业和政府的合作，这有助于促进其对工程公众的影响。

Project AbstractDevelopment of Concrete Damage-Flow Rate Correlation using Integrated Structural Testing andX-Ray TomographyTara C. Hutchinson (PI)1 and Falko Kuester2Concrete is by far the most widely used building material in the United States, with extensive use in the construction of our Nation's buildings, highways, tunnels, water supply and sewage systems and other infrastructure. The strong dependency of the service life of concrete on its transport properties means that investigations, which are geared at studying this internal microstructure, should link these transport properties to damage states of the concrete component. In this proposal, we seek to advance our fundamental knowledge of the damage characteristics of reinforced concrete members and link these characteristics with a fundamental transport property. Although many transport mechanisms are certainly of interest, we select the air permeability as the transport mechanism of interest, as a first step towards other mechanisms and to lay the foundation of the methodology proposed. Our proposed approach includes integrating structural testing of scaled specimens, X-ray computed tomography (CT) imaging, and air flow rate experiments of 20 model reinforced concrete panel-style specimens. Specimens are subjected to uniaxial and biaxial loading conditions, and include parameter variations of geometry (aspect ratio and panel thickness), material details (reinforcing steel ratio and concrete strength), and loading details (axial load and loading protocol). Numerical evaluation of permeability and leakage rate formula available in the literature as well as finite element simulations ofthe experimental specimens will be conducted in an overall effort to develop design guidance regarding the damage leakage rate correlation of reinforced concrete elements.Intellectual Merits - The intellectual merits of this include developments in experimental methods and results, fundamental advancements in the understanding of damage-transport relations of reinforced concrete, and practical impacts on the design industry. The datasets available from this work (both image and numerical data) will spur new discoveries of the internal damage distribution of this complex, composite material. Ultimately, this work will result in design guidance, which accounts for the degrading permeability of concrete. Progress overall in concrete research will lead to a reduction in the cost of new infrastructure and rehabilitation of existing structures, while increasing the service life of one of our most abundantly used construction materials.Broader Impacts - Broader technical impacts include the advancement of our understanding of concrete as a fundamental building material, thus leading to improved designs, with more reliable estimates of properties and hence performance. The acquisition and implementation of the X-ray CT system will have long reaching impacts on the research activities at UC Irvine, for its students and faculty, as well as the local academic community interested in using the system. The educational impacts of the data, images and numerical data, provide a natural haven for reaching all ranges of interested students, from the general public to K-12, and especially the diverse and/or minority student. The natural digital nature of this works makes it viable for Internet dissemination, and we plan to design a special web site (we termed ConcretePedia) devoted to disseminating these image datasets in VRML format (for the general public tointeractively view and learn). This work also actively engages industrial and government collaboration, which helps facilitate its impact to the engineering public.