硅钙渣制备碱激发胶凝材料的凝结与强度协同优化及其机理

Calcium silicate slag is the solid waste of alumina extracting process from high aluminum fly ash by lime sintering process, which is new and unique in China. It is considered to be effective to prepare alkali-activated cementitious material with calcium silicate slag, which has abundant advantages such as high calcium silicate slag consumption and no pre-dealkalization. However, the uncoordinated development of setting time and strength development has placed great restrictions on the application of this material in industry. In order to solve this problem, applied basics and mechanisms of factors affecting the setting behaviors, controllability of setting time, as well as the collaborative optimization of setting time and strength development will be investigated. As a result, the theories based on the collaborative optimization of setting time and strength development of alkali-activated cementitious materials synthesized from calcium silicate slag will be obtained. The achievements obtained will not only provide theoretical supports for the manufacture, popularizing and application of this material, but also contribute to the resource utilization of calcium silicate slag.

硅钙渣是高铝粉煤灰烧结法提取氧化铝后的残渣，是我国特有的一种新兴固体废弃物。以硅钙渣为原料制备碱激发胶凝材料是硅钙渣资源化利用的一条有效途径，其具有硅钙渣无须脱碱预处理、硅钙渣用量高等优点。然而，硅钙渣制备碱激发胶凝材料存在凝结时间与强度发展不协调的问题，极大地限制了该材料在工业生产中的推广和应用。针对这一问题，在已利用硅钙渣成功制备出强度性能优异的碱激发胶凝材料的基础上，本项目研究硅钙渣制备碱激发胶凝材料凝结硬化行为的影响因素、凝结时间的可控性、以及凝结时间与强度发展的协同优化等内容，获得基于硅钙渣制备碱激发胶凝材料凝结时间与强度发展协同优化的基础理论成果。该成果不仅可为该材料在工业生产中的推广应用提供理论支撑，还对促进硅钙渣的资源化利用具有重要的意义。

硅钙渣是高铝粉煤灰烧结法提取氧化铝后的残渣。以硅钙渣为原料制备碱激发胶凝材料是其资源化利用的一种有效途径。然而，该胶凝材料存在凝结时间与强度发展不协调的问题，这极大地限制了其在工业生产中的推广和应用。针对这一问题，本项目研究了硅钙渣矿物组成、颗粒形态、水玻璃参数、养护制度、外掺离子(团)等因素对硅钙渣基碱激发胶凝材料凝结硬化行为的影响规律，通过原料、颗粒优化匹配、外掺离子优化等措施，在保证胶凝材料强度性能的前提下，实现了硅钙渣基碱激发胶凝材料凝结时间与强度发展的协同优化。研究了硅钙渣基碱激发胶凝材料水化过程中的水化放热、产物组成、微观结构等，发现了硅钙渣、矿粉在碱激发反应过程中的协同效应，阐明了硅钙渣基碱激发胶凝材料的凝结硬化机理。进行了硅钙渣基碱激发胶凝材料制备混凝土及泡沫混凝土的探索研究，获得了硅钙渣基碱激发混凝土及泡沫混凝土制备技术。研究成果可为硅钙渣基碱激发胶凝材料在工业生产中的推广和应用提供直接的理论和技术支撑，对硅钙渣的资源化利用具有重要的促进意义。