摘要
大宗工业副产品或废弃物(如粒化高炉矿渣、粉煤灰等)作为辅助胶凝材料用于硅酸盐水泥及混凝土中已有不短的时间。利用辅助胶凝材料可有效缓解水泥生产所带来的制备能耗高、自然资源消耗大、二氧化碳排放等问题。在胶凝材料性能不大幅降低的前提下,要实现大比例取代(≥30%(质量分数))硅酸盐水泥,激发辅助胶凝材料的活性是关键。然而,从材料学观点出发,过往基于宏观性能的经验测试方法,对辅助胶凝材料活性的理解仍相当碎片化。除比表面积等物理性质外,多数辅助胶凝材料的水硬活性取决于其中玻璃相的溶解-沉淀反应。辅助胶凝材料中的玻璃体结构可简化为网络调整体(如Ca、Na等)和网络形成体(如Si、Al等)的物质的量比,如解聚度。近来对Ca OSi O2-Al2O3体系玻璃体的研究,进一步增强了对玻璃体聚合度的理解。玻璃体的溶解与聚合程度及溶液组成(如溶液的饱和程度、阴阳离子类型及浓度、p H等)密切相关。同时,沉淀的生成也会显著改变玻璃体的溶解动力学。本文归纳了辅助胶凝材料玻璃体结构与水硬活性的研究进展,分别对表征辅助胶凝材料玻璃体结构的解聚度及玻璃体中Si(Qn(m Al))聚合程度进行了介绍,分析了玻璃体结构在不同激发条件下的反应活性,以期为制备性能稳定和耐久性优良的低碳建筑材料提供参考。
Industrial by-products or solid waste,such as blast furnace slag,coal-combustion fly ash et al.,have long been used as supplementary cementitious materials(SCM)in Portland cement and concrete.Utilization of SCM can mitigate the problems caused by cement production,including high energy and natural resources consumption,massive carbon dioxide emission.To reach the desired high replacement levels(beyond 30 wt%)of Portland cement without significant performance loss,triggering SCM reactivity is the key.However,from the point of view of material science,the empirical testing approach concerning macroscopic properties led to a quite fragmented understanding of SCM reactivity.In addition to their specific surface area,the hydraulic reactivity of SCM is highly dependent on the dissolution-precipitation reaction of the glass phase within the minerals.The glass structure of SCM can be simply expressed as the molar ratio between network modifer(e.g.Ca,Na)and network former(e.g.Si,Al),such as depolymerization degree in glass chemistry.Recent studies on Ca O-Si O2-Al2 O3 glass enhance the understanding of the structure in terms of Si(Qn(m Al))polymerization units.The polymerization degree of the glass,saturation index in the solution,cation/anion species and their concentration and p H determine the dissolution rate of the glass structure.Besides,formation of precipitates changes the dissolution kinetics as well.This review offers a retrospection of the research efforts on the glass structure of SCM in relation to the hydraulic reactivity.The glass structures in terms of depolymerization degree and Si(Qn(m Al))are presented,respectively.The reactivity of the glass structure under different activation conditions is also elaborated.Therefore,it lays a foundation for the development of the building materials with low-carbon footprint,while stable quality and good durability of the building materials are maintained.
作者
金宇
冯伟鹏
董志君
Manuel Monasterio
李明雨
JIN Yu;FENG Weipeng;DONG Zhijun;Manuel Monasterio;LI Mingyu(School of Material Science and Engineering,Harbin Institute of Technology(Shenzhen),Shenzhen 518055,China;Institute of Technology for Marine Civil Engineering,Shenzhen Institute of Information Technology,Shenzhen 518172,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2021年第3期3016-3020,共5页
Materials Reports
基金
国家自然科学基金委青年基金项目(51708363)。
关键词
辅助胶凝材料
玻璃体
反应活性
激发
supplementary cementitious materials
glass structure
reactivity
activation
作者简介
金宇,助理研究员。2007年6月本硕连读毕业于武汉理工大学,获得工学硕士学位。2016年1月在德国柏林工业大学获得工学博士学位,目前在哈尔滨工业大学深圳研究生院进行博士后研究工作。主要研究领域为碱激发材料,jin_yu1983@hotmail.com。
