养护温度对低pH值水泥基材料水化产物及微结构的影响  

Effect of Temperature on the Microstructure and Hydration Products ofLow pH Cementitious Materials

作　　者：刘卓霖 李相国[3] 吕阳[3] LIU Zhuolin;LI Xiangguo;LYU Yang(School of Emergent Soft Matter,South China University of Technology,Guangzhou 510000,China;China Resources Cement Technology R&D Co.,Ltd,Guangzhou 510000,China;State Key Laboratory of Silicate Materials for Architectures,Wuhan University of Technology,Wuhan 430000,China)

机构地区：[1]华南理工大学软物质学院,广州510000 [2]华润水泥技术研发有限公司,广州510000 [3]武汉理工大学硅酸盐建筑材料国家重点实验室,武汉430000

出　　处：《材料导报》2024年第S01期154-157,共4页Materials Reports

摘　　要：低pH值水泥基材料因其低pH值特性被广泛应用于深地质处置库的建设过程中,但其在深地质处置库中的长期服役过程少有研究报道。通过X射线衍射分析、热重分析和扫描电镜等测试,研究了低pH值水泥基材料在深地质处置环境中不同温度下的长期水化产物和微结构演变规律,结果表明:在50℃长期养护下,低pH值水泥基材料的水化产物仍然有钙矾石,可能是由于低pH值水泥基材料的孔隙溶液氢氧根浓度较低,提高了钙矾石的分解温度,导致其在50℃以上仍能长期稳定存在;养护温度越高,低pH值水泥基材料的结合水含量也越高;养护温度的升高,促使箔片状的C-S-H凝胶向细针状的C-S-H凝胶转变。Low pH cementitious materials are widely used in the construction process of deep geological disposal facilities due to the low pH characteristics,but there are few research reports on their long-term service process in deep geological disposal facilities.The hydration products and microstructure evolution of low pH cementitious materials at different temperatures in deep geological disposal environments were studied through X-ray diffraction analysis,thermogravimetric analysis,and scanning electron microscopy.The results showed that the hydration products of low pH cementitious materials still contain ettringite under long-term curing at 50℃,which may be due to the low concentration of hydroxide ions in the pore solution of low pH cementitious materials,which increases the decomposition temperature of ettringite and leads to its long-term stable existence above 50℃.The higher the curing temperature,the higher the bound water content of low pH cement-based materials.The increase in curing temperature causes the foil like C-S-H gel to transform into the fine needle like C-S-H gel.

关 键 词：低PH值 养护温度 钙矾石 C-S-H凝胶 

分 类 号：TU526[建筑科学—建筑技术科学]