摘要
2014年我国由于腐蚀产生的损失约为21 278亿元,占国家GDP的3.34%。海洋环境中氯离子渗透至混凝土内部导致钢筋锈蚀是海洋环境下混凝土结构损伤的重要原因。海洋不同腐蚀区域的离子浓度、氧气浓度及海水干湿循环作用时间各不相同,这使得海洋不同腐蚀区域中暴露混凝土的氯离子传输速度和分布规律、钢筋锈蚀产物及锈蚀模式、钢筋锈蚀速率存在显著差异。其中海洋浪溅区和高潮位区域因氧气充足、海水干湿循环作用剧烈及浪溅作用导致钢筋混凝土更易破坏。钢筋锈蚀产物体积是原始体积的2～6倍,持续增加的锈蚀产物将导致混凝土开裂、保护层剥落并进一步加速钢筋锈蚀;考虑钢筋非均匀锈蚀、锈蚀产物填充效应、钢筋及混凝土性能的钢筋混凝土锈胀开裂模型将更加精确。根据海洋不同腐蚀区带特点、钢筋混凝土性能及受荷情况,建立不同腐蚀区域中混凝土的氯离子传输模型,钢筋锈蚀速率模型和混凝土锈胀开裂模型有助于准确预测海洋环境下钢筋混凝土的服役寿命。通过对混凝土中钢筋锈蚀的检测与监测有助于实时了解混凝土的服役状态。采用线性极化、电化学噪声和电化学阻抗谱等电化学方法可以较好地检测钢筋锈蚀状态、获得混凝土中钢筋的锈蚀速率。基于电化学原理开发的阳极梯和环形电极、基于钢筋锈胀应力测试的光纤监测技术以及基于数字图像技术获得混凝土中钢筋锈蚀应力应变场,有助于实现对混凝土中钢筋锈蚀的监测,并且部分已应用于海洋工程。相比于普通钢筋,锈蚀钢筋的导电率和导磁率均显著降低,采用电磁感应原理开发钢筋锈蚀装置实现了暴露在海水中的普通钢筋和耐蚀钢筋磁通量变化值与钢筋质量损失线性关系的建立。这也为更精确监测混凝土中钢筋锈蚀全过程、实现混凝土中钢筋锈蚀源定位及损伤程度�
In2014,the loss caused by corrosion in China was about2127.8billion RMB,accounting for3.34%of the country’s GDP.The penetration of chloride ions into the concrete in marine environment leads to the corrosion of reinforced bars,which is the most crucial factor damaging the structures of concrete.Exposed concrete in diverse marine corrosive areas vary in the chloride ion transport velocity and distribution principle,corrosion rate and pattern as well as corrosion products of reinforcement in virtue of the different ion concentration,oxygen concentration and wet-dry cycling time.Among them,reinforced concrete in splash-zone and high-tide area is prone to be vulnerable due to the sufficient-oxygen supply,drastic wet-dry cycling,and splashing effect.The volume of corrosion products are2-6times of the original’s,meanwhile,continuous increasing of corrosion products will lead to concrete cracking,protective layer peeling and further accelerate the corrosion of reinforcement.The corrosion-induced cracking model of reinforced concrete will be more precise by considering non-uniform corrosion,filling effect of corrosion products,properties of reinforcement and concrete.Moreover,it will be more efficient to predict the service-life span of reinforced concrete exposed to diverse corrosive zones inmarine environment by establishing models of chloride ion transportation,reinforcement corrosion rate and corrosion-induced cracking according to the characteristics of diverse corrosive zones in the ocean,the properties of reinforced concrete as well as the load level.The detection and monitoring of reinforcement corrosion in concrete contribute to acquire the information of concrete service status in real time.The corrosion state and ratio of reinforcement can be measured via electrochemical methods such as linear polarization,electrochemical noise and electrochemical impedance spectroscopy.The electrochemical anode ladder and circular electrode develops on the basis of the electrochemical principle,the fiber monitoring techno
作者
李哲
金祖权
邵爽爽
徐翔波
LI Zhe;JIN Zuquan;SHAO Shuangshuang;XU Xiangbo(School of Civil Engineering, Qingdao University of Technology, Qingdao 266033)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2018年第23期4170-4181,共12页
Materials Reports
基金
国家重点研发计划(2017YFB0310000)
国家自然科学基金(51678318)
关键词
混凝土
钢筋
锈蚀
监测
concrete
reinforcement
corrosion
monitoring
