纳米二氧化硅对水泥-粉煤灰体系氯离子固化能力的影响  

Effect of Nano-silica on the Chloride Immobilization Capacity of Cement-Fly Ash System

作　　者：吕周岭 罗英 马保国[1] 谭洪波[1] 刘晓海[1] 陈偏 张挺[1] LYU Zhou-ling;LUO Ying;MA Bao-guo;TAN Hong-bo;LIU Xiao-hai;CHEN Pian;ZHANG Ting(State Key Laboratoo of Silicate Building Materials,Wuhan University of Technology,Wuhan 430070,China;CCCC Second Haebor Engineeering Company Ltd.,Wuhan 430040,Chtna)

机构地区：[1]武汉理工大学硅酸盐建筑材料国家重点实验室,武汉430070 [2]中交第二航务工程局有限公司,武汉430040

出　　处：《硅酸盐通报》2019年第7期1997-2003,共7页Bulletin of the Chinese Ceramic Society

基　　金：“十三五”国家重点研究计划(2016YFC0701003-05)

摘　　要：研究了纳米二氧化硅(NS)对于水泥-粉煤灰体系的氯离子固化能力的影响。同时,采用相应的测试方法分析了NS对于氯离子固化不同因素的影响:采用MIP和抗压强度评价了氯离子阻迁能力;使用XRD和DTG分析了水泥中的氯铝酸盐含量;采用NMR和EDS测试表征了C-S-H凝胶含量和Ca/Si比。实验结果表明,0.5%掺量的NS可以提升氯离子固化率;而高于1%后,将导致氯离子固化率下降。根据微观测试结果,NS加入水泥-粉煤灰体系,其积极作用在于:增加C-S-H凝胶含量,降低孔隙率,即改善物理吸附和阻迁;消极作用在于:阻碍氯铝酸盐的生成,降低C-S-H凝胶的钙硅比,即降低化学结合和物理吸附。The effect of nano-silica(NS) on the chloride immobilization capacity in cement-fly ash system was studied.And the corresponding test methods were used to analyze the different aspects: the chloride ion migration resistance was evaluated by MIP and compressive strength test;XRD and DTG were conducted to analyze the phase assemblage;the amount and Ca/Si ratio of C-S-H gel were verified by NMR and EDS test. The results reveal that NS added with the dosage of 0. 5% can strengthen the chloride immobilization,but the dosage higher than 1% will reduce the chloride immobilization.The behind mechanism is discussed: the positive effects of NS included increasing the C-S-H gel content and reducing the porosity,which can improve the migration resistance and physical adsorption;and the negative effects include hindering the formation of chloroaluminate and reducing the Ca/Si ratio of C-S-H gel,which will decrease the chemical binding and physical adsorption.

关 键 词：纳米二氧化硅 水泥-粉煤灰体系 氯离子固化 

分 类 号：TU528[建筑科学—建筑技术科学]