基于Weibull分布的镁水泥涂层钢筋混凝土耐温性可靠度评价  

Reliability Evaluation of Temperature Resistance of Magnesium Cement Coated Reinforced Concrete Based on Weibull Distribution

作　　者：杨天霞 乔宏霞[1,2,3] 王鹏辉 李金鹏 薛豪 YANG Tianxia;QIAO Hongxia;WANG Penghui;LI Jinpeng;XUE Hao(School of Civil Engineering,Lanzhou University of Technology,Engineering Research Center for Disaster Prevention and Mitigation of Civil Engineering in Westem China of Ministry of Education,Lanzhou 730050,China;Qinghai Salt Lake Institute,Chinese Academy of Sciences,Xining 810000,China;School of Civil and Traffic Engineering,Qinghai Mingzu University,Xining 810000,China)

机构地区：[1]兰州理工大学土木工程学院,西部土木工程防灾减灾教育部工程研究中心,甘肃兰州730050 [2]中国科学院青海盐湖研究所,青海西宁810000 [3]青海民族大学土木与交通工程学院,青海西宁810000

出　　处：《应用基础与工程科学学报》2024年第2期587-600,共14页Journal of Basic Science and Engineering

基　　金：国家自然科学基金项目(51868044,52178216);青海省基础研究计划项目(2022-ZJ-921)。

摘　　要：针对西部盐湖地区建筑结构在恶劣气候环境下工作寿命缩短的现象,提出采用耐盐、耐卤的镁水泥涂层钢筋混凝土(CRMOCC)延长其服役时间.通过对防护层厚度为45mm的试件进行高低温交变湿热加速试验,定期无损检测并结合微观手段进行机理分析,最后选用Weibull分布函数进行可靠性建模,使用最小二乘法、中位秩法、极大似然法3种方法估计可靠度的形状参数和尺度参数.结果表明,加速试验条件除了针棒状水化产物还有纤维絮状的腐蚀产物,随着加速时间增长,内部产物体积膨胀顺着界面过渡区发展,造成部件局部开裂;3种不同参数估计方法估计可靠性存在一定差异:最小二乘法的形状参数值m最小;中位秩法的尺度参数η较大;极大似然法受二分迭代次数影响,形状参数m最大,尺度参数η最小,概率密度函数较大,失效时间越短,失效率越大.In view of the phenomenon that the working life of building structures in the western salt lake area is shortened under the harsh climate environment,salt and halogen resistant magnesium cement coated reinforced concrete(CRMOCC)is proposed to extend its service life.Through the high and low temperature alternating heat and humidity accelerated test of the specimen with a protective layer thickness of 45 mm,the mechanism analysis was carried out by means of regular non-destructive testing and micro means.Finally,the Weibull distribution function was selected for reliability modeling,and the shape parameters and scale parameters of reliability were estimated by least square method,median rank and maximum likelihood.The results show that:The accelerated test conditions include needle-like hydration products and fiber flocculent corrosion products.With the increase of acceleration time,the volume expansion of internal products along the interface transition zone causes local cracking of components.The reliability of the three different parameter estimation methods are different to a certain extent:the shape parameter value m of the least square method is the smallest,the scale parameter of the median rank method is larger,and the maximum likelihood method is affected by the number of binary iterations.The shape parameter m is the largest,the scale parameter n is the smallest,the probability density function is larger,the shorter the failure time,the greater the failure rate.

关 键 词：镁水泥涂层钢筋混凝土(CRMOCC) Weibull分布函数 参数估计方法 可靠度 最小二乘法 中位秩 极大似然法 

分 类 号：TU511[建筑科学—建筑技术科学]