EAGER Collaborative Research: Development of Synthetic Fly Ash Glass as a Model System for Investigating Fly Ash Reactivity

该奖项是根据2009年美国复苏和再投资法案(公法111-5)资助的。这项急切的研究的目的是证明使用合成飞灰玻璃作为系统研究飞灰反应性的模型的可行性，而不是使用真正的飞灰。它将证明，合成飞灰样品将产生与实际飞灰一致的反应性数据，同时能够使用不能用于实际飞灰的分析方法。这将为今后系统研究飞灰活性奠定基础。在这项拟议的研究中，将根据实际飞灰中识别出的特征团簇的组成来制备几种飞灰玻璃。粉状玻璃样品将与整个飞灰样品平行水化并进行分析。此外，典型尺寸为1厘米的合成玻璃单体将在单独的特氟龙容器中水合。这种方法可以根据溶液化学和玻璃成分的不同，通过质量平衡来定量测定玻璃的浸出率。它还允许随后使用扫描电子显微镜和微拉曼分析对凝胶层进行详细分析。这项研究工作将有助于通过加深对控制活性的基本因素的了解，加速混凝土行业对飞灰的使用。这将使基于反应活性的飞灰玻璃在水泥浆体中的行为得到更好的预测，而不是传统的反复试验。这反过来将导致更有效地利用飞灰，这将提高利用率，提供废物的经济使用和更低的二氧化碳排放。

"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)."The objective of this EAGER research is to demonstrate the feasibility of using synthetic fly ash glass as a model for systematic studies of fly ash reactivity instead of using real fly ash. It will demonstrate that synthetic fly ash specimens will produce reactivity data consistent with that of actual fly ashes, while at the same time enabling the use of analytical methods that cannot be used on the latter. This will establish the basis for future systematic studies of fly ash reactivity. In this proposed research, several fly ash glasses will be prepared with compositions based on those of characteristic clusters identified in real fly ash. Powdered glass samples will be hydrated in parallel with whole fly ash specimens and analyzed. In addition synthetic glass monoliths with typical dimensions of 1 cm will be hydrated in individual Teflon containers. This approach enables quantitative determination by mass balances of the glass leach rates as a function of solution chemistry and glass composition. It also permits the subsequent detailed analysis of the gel layer using SEM and micro-Raman analysis. This is not feasible for whole fly ashes.This research effort will help accelerate the usage of fly ash by the concrete industry through an improved understanding of fundamental factors controlling reactivity. This will lead to the better prediction of fly ash glass behavior in cement paste based on its reactivity instead of trial and error by conventional tests. This in turn will lead to a more effective use of fly ash, which will increase the utilization rate and provide economical use of a waste material and lower emissions of CO2.