耦合盐溶液环境下钢筋/混凝土Weibull耐久性寿命预测方法  

Weibull durability life prediction method of reinforced concrete in environment of coupled salt solution

作　　者：李刊 魏智强 乔宏霞[1,3] 路承功[1] 郭健 黄尚攀[2] LI Kan;WEI Zhiqiang;QIAO Hongxia;LU Chenggong;GUO Jian;HUANG Shangpan(School of Civil Engineering,Lanzhou University of Technology,Lanzhou 730050,China;State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals,Lanzhou University of Technology,Lanzhou 730050,China;Western Center of Disaster Mitigation in Civil Engineering of Ministry of Education,Lanzhou University of Technology,Lanzhou 730050,China)

机构地区：[1]兰州理工大学土木工程学院,兰州730050 [2]兰州理工大学省部共建有色金属先进加工与再利用国家重点实验室,兰州730050 [3]兰州理工大学西部土木工程防灾减灾教育部工程研究中心,兰州730050

出　　处：《复合材料学报》2021年第7期2370-2382,共13页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金(51168031,51868044);兰州理工大学红柳一流学科建设计划。

摘　　要：根据兰州地铁沿线站台服役环境,配置含有SO_(4)^(2−)、Cl^(−)、Mg^(2+)的耦合盐溶液,将钢筋/混凝土试件置于耦合盐溶液中每隔90天利用电化学工作站进行无损检测,选择Weibull分布建模,通过最小二乘法和BLUE法得到退化分布的固定参数估计值和动态参数估计值。结果表明:耦合盐溶液环境中腐蚀离子通过扩散、渗透及电化学迁移等方式到达钢筋表面,导致钢筋附近pH值降低,钝化膜由完整状态过渡到局部破损状态。可靠度曲线均呈现出三阶段变化特点,动态参数估计值中三次型尺度参数的可靠性寿命最接近固定参数值可靠性寿命,失效率最大;指数型尺度参数可靠性寿命最短,失效率最小;幂次型介于两者之间。且动态参数函数必须满足一阶导数及函数值为正的要求,否则可靠度计算结果为复数。尺度参数的函数形式对可靠度曲线影响大于形状参数的函数形式对可靠度曲线的影响。尺度参数函数类型一定时,形状参数函数类型对寿命结果影响较大,尺度参数函数类型变化时,可靠性曲线均发生较大变化。According to the service environment of the platform along Lanzhou Metro Line,coupled salt solutions containing SO_(4)^(2−),Cl^(−)and Mg^(2+)were allocated.The reinforced concrete specimens were placed in a coupled salt solution for nondestructive testing every 90 days.Weibull distribution model was selected.Fixed and dynamic parameter estimates of the degradation distribution were obtained by least square method and BLUE method.The results show that the corrosion ions in coupled salt solution reach the surface of steel bar by diffusion,permeation and electrochemical migration.The pH value near the steel bar decreases,and the passivation film transits from undamaged state to partial damaged state.The polarization curve moves towards the direction of negative potential and increasing corrosion current density,and the AC impedance graph shows a double capacitive reactance arc,while the low-frequency impedance arc radius gradually decreases and contracts to the real part of the impedance.The reliability curves show three-stage variation characteristics.Among the dynamic parameter estimates,the reliability life of the cubic scale parameter is the closest to that of the fixed parameter value,the failure rate is the largest,the reliability life of the exponential scale parameter is the shortest,the failure rate is the smallest,the power type is between the two,and the dynamic parameter function must be between them.The first derivative and the value of the function must be positive.Otherwise,the result of the reliability calculation is complex.The influence of the scale parameter function form on reliability curve is greater than that of the shape parameter function form on reliability curve.When the scale parameter function type is fixed,the shape parameter function type has great influence on the life result.However,the reliability curve changes obviously with the scale parameter function type altering.

关 键 词：WEIBULL分布 参数估计 最小二乘法 钢筋/混凝土 可靠性 寿命预测 

分 类 号：TU528[建筑科学—建筑技术科学]