摘要
为了解决西部盐渍土环境下再生混凝土中钢筋的寿命预测问题,采用电化学测试仪对浸泡在氯盐溶液中的再生骨料钢筋混凝土进行了电化学试验,得到了表征钢筋腐蚀的腐蚀电流密度及自腐蚀电位两个指标。利用最小二乘法对Weibull参数做了进一步估计,在Weibull分布函数的基础上对钢筋腐蚀后的寿命进行了建模。结果表明:再生混凝土中的钢筋加速腐蚀至30个月时,其腐蚀电流密度最高为0.0584μA/cm^(2),处于未腐蚀状态;将钢筋低腐蚀与中等腐蚀的界限值(0.5μA/cm^(2))作为钢筋达到高腐蚀状态时的阈值,确定出再生混凝土中钢筋在第750个月时的可靠度函数开始趋近于零,处于中等腐蚀状态,从而直观反映了钢筋在实际环境中的有效使用寿命,可为再生混凝土中钢筋的维护与检测提供参考。
In order to solve the problem of steel bar life prediction in recycled concrete in the western saline soil environment,the electrochemical test of recycled aggregate reinforced concrete soaked in chloride solution was carried out by using an electrochemical tester,and the corrosion current density and self-corrosion potential of steel bar were obtained.The least-squares method was used to further estimate the Weibull parameters,and the life of the steel bars after corrosion was modeled based on the Weibull distribution function.The results show that when the steel bar in recycled concrete is accelerated to 30 months,the maximum corrosion current density is 0.0584μA/cm^(2),and the steel bars are in non corrosive state.Taking the limit value of low corrosion and moderate corrosion of steel bars(0.5μA/cm^(2))as the threshold value when steel bars reach high corrosion state,it is determined that the reliability function of steel bar in recycled concrete begins to approach zero at 750 months and is in the medium corrosive state,which directly reflects the effective service life of the steel bars in the actual environment.It can provide a reference for the maintenance and detection of steel bars in recycled concrete.
作者
王子健
彭金贵
郭飞
苏睿
乔宏霞
WANG Zi-jian;PENG Jin-gui;GUO Fei;SU Rui;QIAO Hong-xia(Gansu Construction Investment Mining Co.,Ltd.,Lanzhou 730000,China;Gansu Construction Investment Commercial Concrete Co.,Ltd.,Lanzhou 730060,China;Lanzhou University of Technology,Western Civil Engineering Disaster Prevention and Mitigation Engineering Research Center,Ministry of Education,Lanzhou 730050,China)
出处
《混凝土与水泥制品》
2022年第4期84-88,93,共6页
China Concrete and Cement Products
基金
2018年国家自然科学基金项目(51868044)。
关键词
再生混凝土
钢筋
自腐蚀电位
腐蚀电流密度
Weibull分布函数
寿命预测
Recycled concrete
Steel bar
Self-corrosion potential
Corrosion current density
Weibull distribution function
Life prediction
