有机酸活化偏高岭土混凝土性能研究  

Properties of Organic Acid Activated Metakaolin Concrete

作　　者：李安 王彦军 张志杰[3] 范志宏 LI An;WANG Yanjun;ZHANG Zhijie;FAN Zhihong(Key Laboratory of Harbor&Marine Structure Durability Technology,Ministry of Transport,Guangzhou 510230,China;The Third Engineering Company of CCCC Fourth Harbor Engineering Co.,Ltd.,Zhanjiang 524005,China;School of Materials Science and Engineering,South China University of Technology,Guangzhou 510640,China;Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai),Zhuhai 519000,China)

机构地区：[1]水工构造物耐久性技术交通运输行业重点实验室,广州510230 [2]中交四航局第三工程有限公司,湛江524005 [3]华南理工大学材料科学与工程学院,广州510640 [4]南方海洋科学与工程广东省实验室(珠海),珠海519000

出　　处：《硅酸盐通报》2024年第7期2434-2440,共7页Bulletin of the Chinese Ceramic Society

基　　金：南方海洋科学与工程广东省实验室(珠海)河口海岸与岛礁工程创新团队建设项目(311020009)。

摘　　要：高岭土是自然界中常见的一种黏土矿物,是一种层状铝硅酸盐矿物。本文选用小分子草酸和柠檬酸复合有机酸对高岭土进行酸活化处理,然后通过高温煅烧与机械粉磨,制备一种有机酸活化偏高岭土;通过SEM和TEM分析有机酸活化方式对高岭土微观形貌的影响,研究有机酸活化偏高岭土对混凝土力学性能、干缩性能、电通量等宏观性能以及微观孔隙结构的影响。结果表明:有机酸活化使高岭土中部分Si和Al被溶出,层状结构棱角与层间遭到破坏,微观形貌变得相对毛糙,煅烧温度降低160℃,比表面积增大;有机酸活化偏高岭土通过增强混凝土致密性来提升混凝土综合性能,其中28 d抗压强度提升23.2%,28 d电通量降低51.8%,优于偏高岭土和硅灰。Kaolin is a common clay minerals in nature and a layered aluminosilicate mineral.Small molecule oxalic acid and citric acid were selected as composite organic acids,and kaolin was subjected to acid activation treatment to prepare an organic acid activated metakaolin by high temperature calcination and mechanical grinding.The influences of organic acid activation methods on the microstructure of kaolin were analyzed through SEM and TEM,and the influence of organic acid activated metakaolin on macroscopic properties such as mechanical properties,drying shrinkage performance,electrical flux of concrete and microscopic pore structure was studied,and its microscopic mechanism of action was revealed.The results show that organic acid activation leads to the dissolution of some Si and Al in kaolin,causing damage to the edges and interlayer of the layered structure,resulting in a relatively rough microstructure.The calcination temperature decreases by 160℃and the specific surface area increases.Adding organic acid activated metakaolin to concrete can improve the comprehensive performance of concrete by enhancing the compactness of concrete.The compressive strength at 28 d increases by 23.2%,and the 28 d electric flux is reduced by 51.8%,which is superior to metakaolin and silica fume.

关 键 词：高岭土 有机酸活化 有机酸 混凝土 宏观性能 微观结构 

分 类 号：TU526[建筑科学—建筑技术科学]