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

Branch Janelle L, Nashville TN

Investigators

Abstract

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.