基于两参数Weibull分布的镁水泥再生细骨料钢筋混凝土抗盐可靠度评估  

Salt resistance reliability evaluation of magnesium cement recycled fine aggregate reinforced concrete based on two-parameter weibull distribution

作　　者：杨天霞 乔宏霞[1,2,3] 李金鹏 王鹏辉 路承功[1] 文静 YANG Tianxia;QIAO Hongxia;LI Jinpeng;WANG Penghui;LU Chenggong;WEN Jing(Gansu Key Laboratory of Earthquake Prevention and Disaster Mitigation for Civil Engineering,Lanzhou University of Technology,Lanzhou 730050,China;Qinghai Salt Lake Institute,Chinese Academy of Sciences,Xining 810000,China;Qinghai Minzu University,Xining 810000,China;Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources Chinese Academy of Sciences,Xining 810000,China)

机构地区：[1]兰州理工大学土木工程防震减灾重点实验室,兰州730050 [2]中国科学院青海盐湖研究所,西宁810000 [3]青海民族大学,西宁810000 [4]中国科学院盐湖资源综合高效利用重点实验室,西宁810000

出　　处：《复合材料学报》2023年第9期5397-5410,共14页Acta Materiae Compositae Sinica

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

摘　　要：针对盐湖地区建筑结构受到恶劣气候环境和腐蚀性离子双重侵害现象,采用镁水泥再生细骨料钢筋混凝土来缓减构筑物寿命退化速度。通过掺加不同量的再生细骨料并将其埋置在盐渍土中进行恒电流通电加速试验,借助电化学工作站、超声波无损检测技术及SEM、XRD分析微结构演变机制,最后引入两参数Weibull分布函数退化过程对评价指标腐蚀电流密度icorr、相对动弹性模量建模进行可靠度评价。结果表明:掺入质量比为15%、30%和45%的细骨料时,Cl^(-)、CO_(3)^(2-)和SO_(4)^(2-)侵蚀性离子随着再生细骨料掺量的增多侵入试件几率增大,内部结构损伤程度更加显著;大片、块状的锈蚀产物逐渐疏松内部结构导致劣化程度加深,15%、30%掺量试件低腐蚀程度,45%掺量试件则处于严重腐蚀;以动弹模量作为退化参数得到15%、30%、45%再生细骨料掺量试件的服役寿命分别为10000天、7500天、6000天;以腐蚀电流密度icorr得到45%掺量试件的工作寿命为4000天,钢筋腐蚀电流密度耐久性退化相对动弹模量更加敏感,对于镁水泥再生细骨料钢筋混凝土构件的日常维护与检测具有可观的指导意义。In view of the fact that the building structure in the salt lake area is subjected to the double damage of harsh climate environment and corrosive ions,which leads to the phenomenon of shortened life.Magnesium cement recycled fine aggregate reinforced concrete was used to slow down the life degradation speed of the structure.The galvanostatic accelerated test was carried out by adding different amounts of regenerated fine aggregate and burying it in saline soil.With the help of electrochemical workstation,ultrasonic non-destructive testing technology,SEM and XRD,the evolution mechanism of microstructure was analyzed,Finally,the degradation process of the two-parameter Weibull distribution function was introduced to evaluate the reliability of the evaluation index corrosion current density icorr and relative dynamic elastic modulus modeling.The results show that:When mixed with mass ratios of 15%,30%and 45%fine aggregates in the accelerated test environment,aggressive ions such as Cl^(−),CO_(3)^(2−)and SO_(4)^(2−)invade the interior of the specimen with the increase of the content of recycled fine aggregates.The probability increases,and the degree of damage to the internal structure is more significant.The large and block corrosion products gradually loosen,which makes the internal structure deteriorate further.The specimens with 15%and 30%dosage have low corrosion degree,and the specimen with 45%dosage is in serious corrosion.The dynamic elastic modulus is used as the degradation parameter to obtain 15%,30%,45%regeneration.The service life of the samples with fine aggregate content is 10000 days,7500 days and 6000 days,respectively.The working life of the specimen with 45%dosage obtained by the corrosion current density icorr is 4000 days.The corrosion current density durability degradation of steel bars is more sensitive to the dynamic elastic modulus,which has considerable guiding significance for the daily maintenance and inspection of magnesium cement recycled fine aggregate reinforced concrete compone

关 键 词：镁水泥再生细骨料钢筋混凝土 腐蚀电流密度icorr 相对动弹模量 两参数WEIBULL分布 可靠度 

分 类 号：TU525[建筑科学—建筑技术科学] TB333[一般工业技术—材料科学与工程]