氯氧镁水泥混凝土中涂层钢筋的耐久性退化研究  

Study on Durability Degradation of Coated Steel Bar in Magnesium Oxychloride Cement Concrete

作　　者：王鹏辉[1] 乔宏霞[1,2] 冯琼[1] 曹辉[1] 温少勇 WANG Penghui;QIAO Hongxia;FENG Qiong;CAO Hui;WEN Shaoyong(Key Laboratory of Disaster Prevention and Mitigation in Civil Engineering of Gansu Province, Lanzhou University of Technology, Lanzhou 730050, China;Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810083, China)

机构地区：[1]兰州理工大学甘肃省土木工程防灾减灾重点实验室,甘肃兰州730050 [2]中国科学院青海盐湖研究所,青海西宁810083

出　　处：《建筑材料学报》2020年第3期563-571,共9页Journal of Building Materials

基　　金：国家自然科学基金资助项目(51468039,51868044)。

摘　　要：采用氯化镁溶液浸泡加速锈蚀试验,对氯氧镁水泥混凝土中的涂层钢筋进行电化学试验,实测出表征涂层钢筋锈蚀的腐蚀电流密度;以腐蚀电流密度作为退化指标,用最小二乘法、矩估计法、最大似然法进行参数估计,在Weibull函数基础上建立涂层钢筋的锈蚀预测模型;同时采用扫描电镜、X射线衍射仪对涂层钢筋进行微观分析,判断涂层对钢筋的保护作用.结果表明:Weibull函数可以很好地反映涂层钢筋的退化过程,最小二乘法可以很好地描述涂层钢筋的耐久性退化过程,涂层钢筋的最终失效时间为38000d(104.1a)左右,可靠度为0.4时所对应的失效时间R(t0.4)为2960d(8.1a);涂层可以很好地保护混凝土中的钢筋,防止其发生锈蚀.The corrosion was accelerated and tested by immersion in magnesium chloride solution,electrochemical test of coated steel bars in magnesium oxychloride cement concrete was carried out,and the characterization of corrosion current density for the corrosion of the coated steel bars was studied.Taking corrosion current density as the degradation index the least squares method,the moment estimation method and the maximum likelihood method were used to estimate the parameters,the corrosion prediction model of the coated steel bar was established based on the Weibull function.And then scanning electron microscopy and X-ray diffractometer were used to conduct microanalysis on the coated steel bar to judge the protective effect of the coating.The results show that the Weibull function can well reflect the degradation process of the coated steel bar,and the least squares method can well describe the durability degradation process of the coated steel bars.The failure time of coated steel bar is about 38000d(104.1 a),the failure time of R(t0.4)is 2960d(8.1a).The coating can protect steel bar in concrete from corrosion.

关 键 词：腐蚀电流密度 Weibull函数 参数估计 耐久性退化 

分 类 号：TU528.01[建筑科学—建筑技术科学]