水泥与偏高岭土地聚物砂浆碱骨料反应对比研究

A Comparative Study of Alkali Aggregate Reaction of Cement Mortar and Metakaolin Geopolymer Mortar

为减少环境污染,近年来对碱激发胶凝材料的研究逐渐增加,而目前研究大多集中在地质聚合物机理方面,较少涉及其碱骨料反应。本文试图探究高温高碱环境下,碱激发胶凝材料砂浆与传统水泥砂浆碱骨料反应的不同,以推进碱激发胶凝材料的工程应用。通过测量试件不同龄期长度变化,研究掺不同骨料的水泥砂浆和偏高岭土基地聚物砂浆在高温高碱溶液中的变形行为,同时采用XRD、SEM等微观手段分析二者不同龄期产物的组成和微观结构。研究结果表明:地聚物与水泥的碱骨料反应历程存在明显区别,地聚物中不会发生严重的碱骨料反应,工程中能使用碱活性强的骨料;地聚物浆体最终形成(类)沸石结构,其笼式结构能吸附和固溶大量有害碱,能适应海工等强腐蚀性环境。

The research on reducing environmental pollution has gradually increased in recent years. At present, the research mostly focuses on the mechanism of geopolymer, but seldom involves alkali aggregate reaction. This study attempts to explore the difference between alkali-activated cementitious material mortar and traditional cement mortar in high temperature and alkali environment. To promote the engineering application of alkaliactivated cementitious materials, the deformation behavior of cement mortar with different aggregates and metakaolin geopolymer mortar in high temperature and alkali solution is studied by measuring the length changes of samples at different ages. At the same time, the composition and microstructure of products at different ages are analyzed by XRD, SEM and other micro-methods. It is shown that there are obvious differences in the alkaliaggregate reaction process between geopolymer and cement. There will be no serious alkali aggregate reaction in geopolymer, and aggregates with strong alkali activity can be used in engineering. Geopolymer paste eventually forms zeolite-like structure, which can absorb and solve a large number of harmful alkali and adapt to strong corrosive environment such as marine engineering.