Unraveling the Stray Current-Induced Interfacial Transition Zone(ITZ)Effect on Sulfate Corrosion in Concrete  

揭示杂散电流诱导的界面过渡区效应对混凝土硫酸盐腐蚀的影响

作　　者：Yong-Qing Chen Lin-Ya Liu Da-Wei Huang Qing-Song Feng Ren-Peng Chen Xin Kang 陈永青;刘林芽;黄大维;冯青松;陈仁朋;康馨

机构地区：[1]School of Transportation Engineering,East China Jiaotong University,Nanchang 330013,China [2]College of Civil Engineering,Hunan University,Changsha 410082,China [3]Key Laboratory of Building Safety and Energy Efficiency of Ministry of Education&National Center for International Research Collaboration in Building Safety and Environment,Hunan University,Changsha 410082,China

出　　处：《Engineering》2024年第10期130-152,共23页工程（英文）

基　　金：supported by the State Major Program of National Natural Science Foundation of China(52090082);the National Key Research and Development Program of China(2022YFB2602200);the National Natural Science Foundation of China(52178423 and 52378398).

摘　　要：The rail transit in sulfate-rich areas faces the combined effects of stray current and salt corrosion;however,the sulfate ion transport and concrete degradation mechanisms under such conditions are still unclear.To address this issue,novel sulfate transport and mesoscale splitting tests were designed,with a focus on considering the differences between the interfacial transition zone(ITZ)and cement matrix.Under the influence of stray current,the ITZ played a pivotal role in regulating the transport and mechanical failure processes of sulfate attack,while the tortuous and blocking effects of aggregates almost disappeared.This phenomenon was termed the“stray current-induced ITZ effect.”The experimental data revealed that the difference in sulfate ion transport attributed to the ITZ ranged from 1.90 to 2.31 times,while the difference in splitting strength ranged from 1.56 to 1.64 times.Through the real-time synchronization of splitting experiments and microsecond-responsive particle image velocimetry(PIV)technology,the mechanical properties were exposed to the consequences of the stray currentinduced ITZ effect.The number of splitting cracks in the concrete increased,rather than along the central axis,which was significantly different from the conditions without stray current and the ideal Brazilian disk test.Furthermore,a sulfate ion mass transfer model that incorporates reactivity and electrodiffusion was meticulously constructed.The embedded finite element calculation exhibited excellent agreement with the experimental results,indicating its reliability and accuracy.Additionally,the stress field was determined utilizing analytical methods,and the mechanism underlying crack propagation was successfully obtained.Compared to the cement matrix,a stray current led to more sulfates,more microstructure degradation,and greater increases in thickness and porosity in the ITZ,which was considered to be the essence of the stray current-induced ITZ effect.

关 键 词：Interfacial transition zone(ITZ)effect Stray current Sulfate attack Transport mechanism Splitting test MICROSTRUCTURE 

分 类 号：TU528[建筑科学—建筑技术科学]