EAPSI:Evaluating the Performance of Energy By-Products in Cement-Based Waste Forms and Barriers Pertinent to China and the United States

世界各国在妥善管理废物方面一直面临挑战。本研究旨在描述与中国和美国相关的水泥基废物形式、废物屏障和混凝土产品中包含的各种各样的能源副产品，以预测材料耐久性、污染物滞留和环境安全。这项研究将与中国上海同济大学的废物管理专家何品静教授及其研究团队合作进行。通过吸收来自不同国家和经验的废物管理知识，可以为复杂的废物形式和屏障开发更有效的实验技术和改进的材料特性。这项研究的结果将得到实施，以支持改进两国废物管理的决策工具，并促进这些材料的有益再利用，这可以减少材料生产和原材料开采的二氧化碳足迹，同时确保环境安全。降解和未降解的废物形式，用作补充胶凝材料的二次材料，以及含有这些二次材料的混凝土将被分析，以提高对物理化学微观结构的理解，使用各种先进的显微镜技术，包括扫描电子显微镜与能量色散光谱（SEM-EDS），同步辐射微x射线荧光和微x射线衍射，扫描透射电镜与能量色散光谱相结合。具体来说，将研究SEM-EDS中光束相互作用体积的影响，以更好地了解这种类型的分析对异质和复杂废物形式和屏障的局限性。粒度和相组成的影响将首先通过分析均匀的纯元素，然后通过分析更复杂的相，包括氧化物、矿物、废物形式和屏障来研究。将开发算法来解释光束相互作用体积对材料分析的影响。这些结果将用于帮助表征废物形式和屏障的复杂性，改进利用SEM-EDS的材料分析，并更好地理解降解机制，如碳化和氧化，这可能会影响这些材料的长期性能。本项目由国家科学基金EAPSI与中国科技部联合资助。

There are persistent challenges to properly managing waste in countries throughout the world. This study aims to characterize a wide variety of energy by-products contained in cement-based waste forms, waste barriers and concrete products pertinent to China and the United States in order to predict material durability, contaminant retention and environmental safety. This research will be conducted in collaboration with Professor Pin-Jing He, a leading expert in waste management, and his research team at Tongji University in Shanghai, China. By assimilating the knowledge of waste management from different countries and experiences, more efficient experimental techniques and improved material characterization can be developed for complex waste forms and barriers. Results from this study will be implemented to support improved decision making tools for waste management across both countries and to promote beneficial reuse of these materials which can reduce the carbon dioxide footprint for material production and the mining of raw materials while ensuring environmental safety.Degraded and non-degraded waste forms, secondary materials used as supplemental cementitious materials, and concretes containing these secondary materials will be analyzed to improve understanding of the physical-chemical microstructure using a variety of advanced microscopy techniques including scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), synchrotron radiation for micro x-ray fluorescence and micro-x-ray diffraction, and scanning transmission electron microscopy coupled with energy dispersive spectroscopy. Specifically, the impact of the beam interaction volume in SEM-EDS will be investigated to better understand the limitations of this type of analysis for heterogeneous and complex waste forms and barriers. The effect of particle size and phase composition will be investigated by first analyzing uniform pure elements and then by analyzing more complex phases including oxides, minerals, and the waste forms and barriers. Algorithms will be developed to account for the effect of the beam interaction volume on material analysis. These results will be used to help characterize the complexity of the waste forms and barriers, improve material analysis utilizing SEM-EDS, and to better understand the degradation mechanisms such as carbonation and oxidation which can impact the long-term performance of these materials. This NSF EAPSI award was funded in collaboration with the Ministry of Science and Technology of China.