海工结构服役寿命及保护层开裂模式细观数值模拟  

Numerical Simulation of Service Life and Protective Layer Cracking Pattern of Marine Structures

作　　者：陈宣东 刘光焰[1,2] 刘恺德 虞爱平 黄达[1,2] 荣华 CHEN Xuandong;LIU Guangyan;LIU Kaide;YU Aiping;HUANG Da;RONG Hua(Guilin University of Technology,Guilin 541004,China;Guangxi Key Laboratory of New Energy and Building Energy Saving,College of Civil and Architecture Engineering,Guilin 541004,China;Shaanxi Key Laboratory of Safety and Durability of Concrete Structure,Xijing University,Xi’an 710123,China;Central Research Institute)

机构地区：[1]桂林理工大学土木与建筑工程学院,广西桂林541004 [2]广西建筑新能源与节能重点实验室,广西桂林541004 [3]西京学院陕西省混凝土结构安全与耐久性重点实验室,陕西西安710123 [4]中冶建筑研究总院有限公司,北京100088

出　　处：《材料科学与工程学报》2021年第5期776-782,共7页Journal of Materials Science and Engineering

基　　金：国家自然科学基金资助项目(51468014,52078509);国家科技重大专项资助项目(2018ZX06002008);广西自然科学基金资助项目(2020GXNSFBA297034);广西建筑新能源与节能重点实验室资助项目(桂科能19-J-21-4,19-J-21-30)。

摘　　要：通过在钢筋与混凝土交界面处施加时变边界位移建立非均匀锈蚀钢筋锈胀模型,其中混凝土损伤本构采用指数应力软化模型,时变边界位移采用Faraday定律对氯离子浓度积分计算得到。参数化分析保护层厚度、钢筋位置、钢筋直径等因素对服役寿命及保护层开裂模式的影响。研究结果表明,服役寿命随保护层厚度增加而增长,而且增加幅度逐步增大,而钢筋直径变化对服役寿命影响较小,角部钢筋锈蚀则导致结构服役寿命缩短;中部钢筋的锈蚀使得保护层出现三条主裂缝,当保护层较小,保护层破坏模式为凸起式破坏,保护层较大时则将出现层裂;同时,角部钢筋锈蚀将在保护层内形成两条主裂纹,最终导致角部保护层脱落。Predicting the service life of marine structures is of great significance to the repair and safety assessment of marine structures.The corrosion expansion model of non-uniformly corroded steel bar is established by applying time-varying boundary displacement at the interface between steel bar and concrete,in which the damage constitutive model of concrete is based on exponential stress softening model,and the time-varying boundary displacement is calculated by integrating the concentration of chloride ion with Faraday’s law.The effects of cover thickness,steel bar position and steel bar diameter on service life and cover cracking mode are analyzed parametrically.The study shows that the service life increases with the increasing of the cover thickness,but the change of the steel bar diameter has little effect on the service life,and the corrosion of the corner steel bar leads to the decrease of the service life of the structure.The corrosion of the steel bar in the middle leads to three main cracks in the protective layer.When the protective layer is small,the failure mode of the protective layer is convex failure,and the crack is formed when the protective layer is large.The corrosion of the corner steel bar will form two main cracks in the protective layer,which will eventually lead to the fall-off of the corner protective layer.

关 键 词：服役寿命 混凝土细观力学 钢筋锈蚀 保护层开裂 

分 类 号：TU528[建筑科学—建筑技术科学]