CAREER: Increasing the Effectiveness of Mineral Additives in Concrete Through Novel Particle Characterization

这个教师早期职业发展（Career）项目将开发一个强有力的研究项目，通过新的化学表征水平来增加混凝土中补充胶凝材料（scm）作为建筑粘合剂的使用。由于scm是来自不同工业过程的不需要的材料流，因此材料有很大的可变性。该研究将使用由PIs研究小组开发的新型颗粒表征技术来更好地理解、量化、改进和增加scm作为构建粘合剂的使用。目标是：i)通过耦合粒度和化学特性来表征SCM，通过3D颗粒化学作图，使用自主扫描电子显微镜进行快速调查，以及散装化学；ii)通过强度、渗透性、化学收缩率和水化热随时间的变化来量化SCM作为混凝土粘合剂的短期和长期性能；iii)了解SCM中不同化学相影响混凝土粘合剂性能的机制。混凝土是世界上使用量第二大的商品。在混凝土中使用scm具有提高混凝土强度、耐久性、经济性和可持续性的能力。由于材料的高度可变性，目前在混凝土中使用scm受到限制。这项研究将为化学相、它们的分布以及这些相如何与水化水泥浆体发生反应提供新的基础知识。最终，这些相互作用将用于了解这如何影响包含SCM的混凝土的性能和性能，从几个小时到一年多。此外，在这项研究中建立的技术将有助于许多需要复杂颗粒表征和允许在不同环境中对其反应和结构变化进行时间分辨测量的应用。这些方法可应用于生物材料、药品、土工材料、聚合物、工业废料等领域。教育活动还将通过建立课后辅导计划和创建在线教学模块，提高代表性不足的小学生对STEM领域的认识。

This Faculty Early Career Development (CAREER) project will develop a strong research program to increase the use of supplementary cementitious materials (SCMs) as construction binders in concrete through new levels of chemical characterization. Since SCMs are unwanted material streams from different industrial processes, there is much variability in the materials. The research will use novel particle characterization techniques developed by the PIs research group to better understand, quantify, improve and increase the use of SCMs as construction binders. The objectives are: i) characterize SCMs by coupling particle size and chemistry, through 3D particle chemical mapping, rapid investigation with autonomous scanning electron microscopy, and bulk chemistry, ii) quantify the short term and long term performance of SCMs as concrete binders through strength, permeability, chemical shrinkage and heat of hydration changes over time, iii) understand the mechanisms by which different chemical phases in the SCM impact performance as a concrete binder. Concrete is the second most used commodity in the world. The use of SCMs in concrete has the ability to improve the strength, durability, economy and sustainability of concrete. Current use of SCMs in concrete is limited because of the high variability of the material. This research will provide new fundamental knowledge of chemical phases, their distribution, and how these phases react with hydrating cement paste. Ultimately these interactions will be used to understand how this impacts the properties and performance of the concrete containing the SCM from a few hours to over a year. Furthermore, the techniques established in this research will be useful for a number of applications that require complex particle characterization and allowing time resolved measurements of their reactions and structural changes in different environments. These methods can be applied to biomaterials, pharmaceuticals, geo-materials, polymers, industrial waste products. The educational activities will also increase the awareness level of STEM fields with underrepresented elementary students through the establishment of an after school mentoring program and the creation of online teaching modules.