EAGER: Spherical Porous Reactive Aggregates from Coal Bottom Ash

这个探索性研究早期概念基金（EAGER）项目旨在研究利用毫无价值的煤底灰生产用于混凝土材料的球形多孔反应性骨料（SPoRA）的基本物理和化学机制。全国燃煤电厂产生的底灰量大，没有工程价值，社会环境成本高。本项目旨在将这种废料转化为增值活性骨料，通过加强骨料与硬化水泥之间的粘结来提高混凝土的抗裂性。该研究将估算使用煤底灰作为建筑材料在能源、温室气体排放和垃圾填埋方面的节省。该项目将通过将合作培训纳入本研究来培养本科生。大一和大四的设计项目将从这个项目中萌芽。参与该项目的本科生将作为参加该机构STEM学者计划的高中生的导师。残余碳煤底灰通过烧结过程转化为混凝土骨料材料，通过定时启动熔体轨迹内的体积膨胀。在应用SPoRA的热力学和动力学建模和实验合成的同时，将对其生命周期对传统轻质聚集体的环境影响进行基准测试。假设是部分熔化氧化物并随后燃烧残余的碳将产生一种多孔材料，该材料被玻璃层包裹，具有火山灰反应性。高火山灰活性的非晶态表面改变了界面过渡区的微观结构，增强了混凝土的抗裂性。聚集体的主要结晶核心提供了强度。通过控制非晶相作为功能设计要求来创建轻骨料所获得的知识可转移到其他烧结轻骨料。

This Early-concept Grant for Exploratory Research (EAGER) project pursues research to understand the fundamental physical and chemical mechanisms for producing spherical porous reactive aggregates (SPoRA) for concrete materials using worthless coal bottom ash. Coal power plants around the country generate large volumes of bottom ash with no engineering value and a high environmental cost to the society. This project aims to convert this waste material into value-added reactive aggregates that will improve the cracking resistance of concrete by strengthening the bonding between aggregates and hardened cement. The research will estimate the savings in energy, greenhouse gas emissions, and landfilled waste when using coal bottom ash for construction materials. The project will nurture undergraduate students by incorporating co-op training into this research. Freshman and senior design projects will germinate from this project. Undergraduate students working on this project will serve as mentors for the high school students who are participating in the STEM scholar program of the institution. Residual carbon coal bottom ash is converted to concrete aggregate materials through a sintering process by timing the initiation of volume expansion within the melt trajectory. In parallel to applying thermodynamic and kinetic modeling and experimental synthesizing of SPoRA, will be the benchmarking of its life cycle environmental impacts against conventional lightweight aggregates. The hypothesis is that partially melting the oxide compounds and subsequently combusting the residual carbon will create a porous material encapsulated by a glassy layer that exhibits pozzolanic reactivity. The highly pozzolanic reactive amorphous surface alters the microstructure of the interfacial transition zone, enhancing the cracking resistance of concrete. The dominantly crystalline core of the aggregates provides the strength. The knowledge acquired from creating lightweight aggregates by controlling the amorphous phase as a functional design requirement is transferable to other sintered lightweight aggregates.