CAREER: Linking Pore Structure, Performance, and Material Design of a Sustainable Macroporous Concrete for Multifunctional Applications

增强型多孔混凝土（EPC）是一种相对较新的混凝土类型，具有高于正常的孔隙率和孔隙连通性，从而促进了诸如暴雨径流控制和公路噪音缓解等应用。 该CAREER提案的基本目标是通过涉及体视学方法、断裂特性、多孔介质流动和数学优化的多学科方法，将EPC的孔隙结构特征和性能与其材料设计参数联系起来。 从二维EPC图像的几何数据将体视学解释使用随机几何，和一种新的孔隙度预测方法的基础上开发的颗粒堆积理论，以建立材料设计参数和孔隙结构特征之间的相关性。 孔隙结构特征将涉及：（i）使用断裂标准的机械行为，涉及韧性和强度，从而提供了裂纹钝化和更高的空隙率之间的竞争的理解，（ii）渗透性使用X射线断层扫描，三维重建的平面图像，和分形模型，和（iii）污染物截留效率使用多相流理论和重建的模型。 由于EPC系统需要设计一个以上的性能要求，多目标优化程序将被用来达到一个可行的材料设计参数集。这将通过孔结构特征促进材料设计和性能之间的关系的发展。该CAREER提案将为EPC系统提供急需的基于性能的设计方法，并实现性能预测。这将有助于确定EPC性能的测试方法的开发，并将促进EPC设计从目前采用的试错法过渡到科学过程。 本提案中的教育计划通过基于问题的设计和学习，教学实验室课程的开发以及K-12推广计划与研究部分紧密联系在一起。 一个构思-实施-设计-操作（CDIO）的方法将被用来把基于问题的学习和设计付诸实践，学生将负责设计，构建和评估一些小型EPC试验台系统。 将开发一个教学实验室课程，本科生可以在其中对与水泥基材料相关的结构化主题进行研究。 现有的GK-12计划在克拉克森将被用来作为一种工具，强调动手活动和工程问题的解决，以初中和高中学生使用EPC作为模型多孔工程材料，从而整合研究和推广。

Enhanced Porosity Concrete (EPC) is a relatively new class of concrete having higher than normal porosity and pore connectivity, thus facilitating applications such as storm water runoff control, and highway noise mitigation. The fundamental objective of this CAREER proposal is to link the pore structure features and performance of EPC to its material design parameters through a multi-disciplinary approach that involves stereological methods, fracture properties, porous media flow, and mathematical optimization. Geometrical data from two dimensional EPC images will be stereologically interpreted using stochastic geometry, and a novel porosity prediction method based on particle packing theory developed to establish correlations between material design parameters and pore structure features. Pore structure features will be related to: (i) mechanical behavior using a fracture criterion that involves both toughness and strength, thus providing an understanding of the competition between crack-blunting and higher void fraction, (ii) permeability using X-ray tomography, three-dimensional reconstruction of planar images, and fractal models, and (iii) pollutant retention efficiency using multi-phase flow theories and reconstructed models. Since EPC systems need to be designed for more than one performance requirement, a multi-objective optimization procedure will be used to arrive at a feasible set of material design parameters. This will facilitate the development of relationships between material design and performance through the pore structure features. This CAREER proposal will result in a much needed performance-based design methodology for EPC systems, and enable predictions of performance. This will aid in the development of test methods to determine EPC properties, and will facilitate the transition of EPC design to a scientific process from the currently employed trial and error methods. The educational plan in this proposal is strongly tied with the research component through problem-based design and learning, development of a teaching lab course, and K-12 outreach program. A conceive-implement-design-operate (CDIO) approach will be used to put the problem-based learning and design into practice where the students will be responsible for designing, constructing, and evaluating a few small EPC test bed systems. A teaching lab course, where the undergraduate students can do research on structured topics related to cement-based materials will be developed. The existing GK-12 program at Clarkson will be used as a vehicle to emphasize hands-on activities and engineering problem solving to middle and high school students using EPC as a model porous engineering material, thus integrating research and outreach.