EDTA改性CaAl-LDH对水泥基材料性能的影响  

Effect of EDTA Modified CaAl-LDH on Properties of Cement-Based Materials

作　　者：袁慧慧 秦兴 孙钰璇 叶建雄[1] 陈梦竹 吴芳[1] 蔡渝新 余林文[1] YUAN Huihui;QIN Xing;SUN Yuxuan;YE Jianxiong;CHEN Mengzhu;WU Fang;CAI Yuxin;YU Linwen(College of Materials Science and Engineering,Chongqing University,Chongqing 400045,China;Jiangsu Nigao Science and Technology Co.,Ltd.,Changzhou 213141,China;School of Materials Science and Engineering,Sun Yat-sen University,Guangzhou 510275,China;State Key Laboratory of Ocean Engineering,School of Naval Architecture,Ocean and Civil Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]重庆大学材料科学与工程学院,重庆400045 [2]江苏尼高科技有限公司,常州213141 [3]中山大学材料科学与工程学院,广州510275 [4]上海交通大学船舶海洋与建筑工程学院,海洋国家重点实验室,上海200240

出　　处：《硅酸盐通报》2023年第5期1578-1588,共11页Bulletin of the Chinese Ceramic Society

基　　金：重庆市留学人员回国创业创新支持计划(cx2021083)。

摘　　要：本文以乙二胺四乙酸二钠作为改性剂,通过焙烧还原法成功制备出改性CaAl-LDHs阻锈剂(CaAl-EDTA LDH),并探明了CaAl-EDTA LDH对水泥基材料宏观性能(流动度、凝结时间、力学性能)及微观性能(产物组成、水化热、孔结构)的影响规律。此外,成型了内埋钢筋的砂浆试件,设置了两种腐蚀模式(内掺氯盐+干湿循环、干湿循环),模拟测试不同掺量(0%、0.5%、1.0%、2.0%、4.0%,质量分数)CaAl-EDTA LDH对实际钢筋混凝土体系的防护效果。结果表明,掺量为0.5%和1.0%的CaAl-EDTA LDH会促进水泥矿物溶解,提高水化放热量,使砂浆早期强度提升。但是EDTA自身具有缓凝效果,当CaAl-EDTA LDH掺量为4.0%时,砂浆水化放热量及早期水化产物生成量严重降低,而28 d净浆总孔隙率增加了4%左右。腐蚀试验结果表明干湿循环模式下CaAl-EDTA LDH未表现出阻锈性能,而在双重腐蚀模式下,CaAl-EDTA LDH在经历90次干湿循环后仍对砂浆中的钢筋存在优异的防腐效果,但掺量应控制在1.0%~2.0%。本文开发的新型阻锈剂对延长钢筋混凝土寿命、提高结构耐久性具有参考意义。The modified CaAl-LDHs corrosion inhibitor(CaAl-EDTA LDH)was prepared by calcination reduction method with EDTA-2Na as modifier,and the effect of CaAl-EDTA LDH on the macro-properties(fluidity,setting time,mechanical properties)and micro-properties(product composition,hydration heat,pore structure)of cement-based materials was investigated.Besides,two corrosion modes were set up to simulate the protective effect of CaAl-EDTA LDH with different content(0%,0.5%,1.0%,2.0%,4.0%,mass fraction)on the embedded reinforced mortar specimens.The results show that the addition of 0.5%and 1.0%CaAl-EDTA LDH promotes the dissolution of cement minerals,increases the hydration heat release,and improves the early strength of mortar.However,EDTA has a retarding effect.When the content of CaAl-EDTA LDH is 4.0%,the hydration heat release and the formation of early hydration products of mortar seriously reduces,while the paste total porosity of 28 d increases by about 4%.Moreover,corrosion test results indicate that CaAl-EDTA LDH does not show corrosion resistance in dry-wet cycle mode,while it shows excellent corrosion resistance on reinforcement in mortar after 90 times dry-wet cycle under dual corrosion mode with the content controlled in 1.0%~2.0%.The new type of corrosion inhibitor in this paper has reference significance for prolonging service life of reinforced concrete and improving durability of structures.

关 键 词：层状双金属氢氧化物 乙二胺四乙酸二钠 改性 阻锈剂 钢筋混凝土 氯盐 

分 类 号：TU528[建筑科学—建筑技术科学]