预埋式钢筋腐蚀监测电化学传感器研究现状与应用中的问题分析

概述了钢筋腐蚀监测电化学传感器的研究发展现状,分析了现有成熟的电化学传感器在实际工程应用中存在的问题,并为电化学传感器在钢筋混凝土中推广应用,更准确的反映实际混凝土结构钢筋的腐蚀状况的研究提出了建议。     

钢筋腐蚀监测的光纤传感技术

采用电化学方法制备了用于混凝土结构钢筋腐蚀监测的光纤传感器,该方法基于电沉积于光纤纤芯上的敏感膜能够将腐蚀信息传递给光纤内传导的光波,从而获取腐蚀信息,实现腐蚀监测。证明了采用光纤传感技术监测混凝土结构筋腐蚀是可行的。     

钢筋混凝土的腐蚀监测/检测

混凝土中钢筋的腐蚀是混凝土结构破坏和修复的主要原因之一，钢筋腐蚀速率的监测和腐蚀状况的判定可以为钢筋混凝土结构的剩余载荷和结构的耐久性提供基础数据。本文叙述了混凝土中钢筋腐蚀的监测技术，包括7种基于电化学基础的测定瞬时腐蚀速率的方法和3种物理方法，给出了测定电位(或电位图)、线性极化、电化学噪音、宏观电池电流、脉冲电流、电化学阻抗谱、恒电量方法的原理、装置和实施方法。同时简单介绍了利用电阻探针法、光纤传导方法、微波反射法测定腐蚀速率和其他腐蚀相关参数(电阻率、pH、Cl^-)的测定方法。     

混凝土结构光纤光栅腐蚀传感器

提出了一种新型测量钢筋锈蚀的光栅传感器,即双筋腐蚀光栅传感器.这种传感器将光纤布拉格光栅粘贴固定于两根紧密排列的钢筋上表面.当钢筋锈蚀后,体积膨胀而使光纤光栅产生拉伸应变,光纤光栅的反射光波长将发生变化,所以通过测量光纤光栅的波长就可以测得钢筋锈蚀程度.这种传感器利用光纤光栅波长位移来监测钢筋锈蚀,能够间接反映钢筋锈蚀程度,且不受锈蚀因素的影响,可用于混凝土结构中钢筋锈蚀的早期监测.     

钢筋锈蚀状态的超声导波监测试验

为了对钢筋锈蚀进行监测，基于压电超声导波法，采用埋置于混凝土内部贴附于钢筋两端的压电传感器，对电加速锈蚀的纯钢筋和混凝土中的钢筋以及未电加速方式锈蚀的混凝土中钢筋进行主动锈蚀监测。监测结果表明，在钢筋锈蚀过程中，其超声导波信号振幅变化可以明显监测到腐蚀的5个阶段，即钝化脱钝-起锈-脱黏-继续锈蚀-严重锈蚀；且导波信号振幅不随着锈蚀的加深而持续降低，而是具有一定的变化规律。使用超声导波监测包裹于混凝土中的钢筋锈蚀时，可以直接通过测定导波信号振幅不同阶段来区分钢筋所处的腐蚀阶段。该结论为工程实际监测提供了有力的数据支撑和支持。     

钢筋混凝土中钢筋锈蚀与防护研究概况

为了对进一步研究钢筋混凝土中钢筋的腐蚀与防护提供参考,本文通过查阅相关文献,对钢筋锈蚀对钢筋混凝土力学特性的影响、钢筋锈蚀的影响因素、钢筋锈蚀的检测与评定方法以及钢筋锈蚀的防护与修复技术进行了论述。结果表明,钢筋锈蚀对钢筋混凝土力学特性的影响有三个方面;氯化物、混凝土碳化、硫酸盐、水和氧气、环境温度、混凝土裂缝是影响钢筋锈蚀的因素;钢筋锈蚀的检测与评定方法有电位图法、电位梯度法、交流阻抗法、恒电流脉冲法、极化曲线法、线性极化法、光纤监测法。指出完善混凝土中钢筋锈蚀的智能检测方法,建立更符合工程实际的混凝土结构失效评估指标体系,研究具有实际应用价值的混凝土中钢筋锈蚀的防护方法及混凝土中已锈蚀钢筋的修复方法是今后研究的发展方向。     

混凝土中钢筋的腐蚀与防护

钢筋腐蚀引起混凝土结构的破坏,钢筋在混凝土中腐蚀的基本历程,混凝土中钢筋腐蚀的研究方法和控制方法,作者研究成果,未来的研究方向。     

环氧树脂涂层钢筋在混凝土结构中的应用

介绍了混凝土结构中钢筋的腐蚀机理,在此基础上介绍了环氧树脂涂层钢筋的主要特点及其在混凝土结构中的应用,希望能为延长钢筋使用寿命、增强混凝土结构耐久性提供帮助.     

钢筋腐蚀引起混凝土结构破坏的修补对策

4 混凝土碳化引起钢筋腐蚀的基本修补方法 混凝土碳化引起的钢筋腐蚀,指的是钢筋的去钝化和腐蚀唯一地是由混凝土碳化引起的,而混凝土的氯化物含量明显地低于能使钢筋去钝化所需的临界值(见下文)。图5中列出混凝土碳化引起的钢筋腐蚀的结构可以采用的基本修补方法。这些方法可以综合     

腐蚀监测技术研究现状与展望

腐蚀给世界各国造成的经济损失是巨大的，为充分认识腐蚀、表征腐蚀、控制腐蚀，腐蚀科研工作者对于腐蚀监测技术探索的脚步从未停歇。针对当前腐蚀监测技术状态，本文重点从监测技术种类、监测原理、监测参数、监测技术应用优缺点等方面开展了详尽的论述，同时讨论了腐蚀监测技术在工程实际应用中存在的一些问题，并对未来腐蚀监测技术的发展做了一些展望。     

Remote corrosion monitoring of the RC structures using the electrochemical wireless energy-harvesting sensors and networks

Essentially, the corrosion process of the steel bar in reinforcing concrete structures is a series of electrochemical reactions. Therefore, the released energy during these reactions provides the opportunities to identify the corrosion status and power the wireless corrosion monitoring sensors. Furthermore, the recognition of the corrosion status has been realized with active monitoring techniques (AMTs) and passive monitoring techniques (PMTs). Additionally, the sensor mote platform that harvests the corrosion energy has been designed for corrosion monitoring, and then how to network these sensors to remotely access the corrosion data has been discussed. The preliminary experiment has been conducted to validate the micro corrosion energy.     

光纤金属腐蚀传感器研究及应用进展

光纤传感技术具有诸多传统的检测方法不具备的优点,如防电磁干扰、传感器体积小、重量轻,可以进行远距离探测等,近年来越来越多的应用于金属腐蚀监测领域。本文综述了探测透射光强型、光纤光栅型、荧光光谱型等类型的光纤金属腐蚀传感器的工作原理、研究应用现状及发展趋势。     

电化学噪声技术检测核电环境材料的腐蚀损伤

探讨和解决了电化学噪声技术在核电环境材料腐蚀损伤检测应用的关键问题,建立了基于零阻电流（ZRA）检测的SCC电化学噪声测试体系。采用小面积的Pt或表面热喷涂陶瓷涂层的工作电极材料作为对电极,研制适用于核电现场检测的多种电化学传感器。运用Compact RIO模块化仪器和设计制作的基于ZRA电路的电化学噪声测试模块,实现电位一电流噪声的同步测量和采集。成功研制出便携式核电材料损伤检测系统。应用研制的测试系统和电化学传感器研究了高温高压和动态水环境304不锈钢的电化学噪声谱特征。并初步实现了在役核电站辅助车间不锈钢管道表面直接腐蚀检测和钢厂动力锅炉连续排污管的现场腐蚀检测,取得了比较满意的结果。     

Development of corrosion sensors for monitoring steel‐corroding agents in reinforced concrete structures

Corrosion sensors were devised to develop a system whereby the depth of chloride permeation from concrete surfaces can be monitored non‐destructively on a real‐time basis using such sensors embedded in cover concrete of reinforced concrete structures. The proposed corrosion sensors were subjected to accelerated corrosion in NaCl solutions, mortar specimens intrinsically containing chlorides, and mortar specimens impregnated with chloride solutions, while recording the changes in the resistance readings. The resistance of sensors increased as the degree of corrosion increased. The time to the first change in the resistance decreased and the corrosion degree and resistance increased as the chloride concentration increased and as the distance from mortar surfaces decreased. It was therefore confirmed that the corrosion sensors are capable of monitoring the depth of chloride permeation with sufficient accuracy.     

多孔薄板式气体腐蚀性探测电池

研制了一种多孔薄板结构的电化学探测电池,能按气体环境腐蚀性的强弱转换成电池电流输出。根据输出的电流及其积分电量可计算金属在气体中的瞬间及平均腐蚀速度。本文介绍这种探测电池的性能和使用范围,着重讨论碳钢电解电池的电流和真实腐蚀失重之间的关系,并列举了它们在大气,工业废气,高压管道天然气介质中在线腐蚀监测以及耐蚀材料筛选研究等方面的应用。     

Experimental methods designed for measuring corrosion in highly resistive and inhomogeneous media

Corrosion measurement in highly resistive and inhomogeneous media can be very challenging due to practical difficulties in setting up and maintaining testing cells and sensors, problems associated with IR potential drops and nonuniform polarisation current distribution, and limitations associated with localised corrosion monitoring and detection. Many technological innovations have been made over the past decade to address these issues with reports scattered throughout the literature. This paper provides an overview of innovative experimental methods designed for corrosion testing and monitoring in highly-resistive and inhomogeneous media, with particular focus on localised corrosion measurement using electrode array and electrochemical noise techniques.     

Optimizing periodic inspections in chemical plants by corrosion monitoring

An efficient industrial corrosion monitoring system would give information about the corrosion activity and corrosion damage of critical components within a chemical plant in real time. A research project to develop an industrial tool for the simultaneous monitoring of general and localized corrosion was initiated. General and localized corrosion can be monitored by combining several non‐destructive techniques. An industrial probe for corrosion monitoring is an excellent tool for an intelligent material selection, to identify critical process conditions or to optimize the use of corrosion inhibitors. The highest added value of an industrial tool for corrosion monitoring is its capacity to optimize periodic inspections.     

Listen to corrosion at work — A newly developed versatile corrosion monitoring tool ready for plant application

The basic principle of a new approach of electrochemical noise (ECN) diagnostics, the Coulombs counting method, is outlined, and the wide range of application as an online‐monitoring tool in technical corrosion systems is exemplified. It is shown that corrosion monitoring can be achieved with ECN sensors as simple as monitoring temperatures. A special feature of this method is that corrosion in crevices or under deposits can be investigated under real‐time conditions. This allows to monitor the efficiency of mitigation measures, e.g. application of corrosion inhibitors, under crevice corrosion conditions. The new ECN diagnostic approach listens to the message of corroding systems and translates it into technically relevant information.     

Monitoring of chloride-induced corrosion in steel rebars

Chloride-induced corrosion is very serious for steel rebar, because chloride-induced corrosion causes local disruption in the passive layer of the steel, forming surface pits. This paper proposes a novel corrosion monitoring method for steel rebars on the basis of the stress concentration in the plane stress condition caused by chloride-induced corrosion. The fundamentals of corrosion monitoring and the design concept of the proposed sensor are illustrated. The influence factors for corrosion monitoring are simulated to improve the sensitivity. Potentiostatic accelerated corrosion tests are conducted to evaluate the efficacy. The studies indicate that this indirect method for monitoring changes of physical properties caused by corrosion is effective. Influence factors in chloride-induced corrosion can be neglected, as compared with electrochemical techniques. The proposed corrosion monitoring method can provide useful information to evaluate the risk of corrosion initiation and propagation for steel rebars.     

Long-term Field Corrosion Monitoring in Supporting Structures of China Xiamen Xiangan Subsea Tunnel

Xiamen Xiangan Subsea Tunnel is the first undersea tunnel constructed in China.It has become the major undersea pathway connecting Xiamen Island and Xiangan District since its operation in 2010.The total length is 6.05 km with the undersea length of 4.2 km.In an effort to onsite-monitor reinforcement corrosion in concrete structures,the commercially available CorroWatch multiprobe sensors and ERE-20 reference electrodes were pre-embedded in the selected locations and positions of supporting structures during the tunnel constructions.The real-time data have been collected annually by onsite measurements for 6 years.In this paper,the feasibility of the onsite corrosion monitoring system and suitability of the measured parameters including corrosion current,potential and temperature are discussed based on the preliminary results.The measured typical cyclic-type variations in corrosion current and temperature with monitoring time might be related to the seasonal changes during the annual routine measurements.The widely scattered corrosion potentials that are fluctuated complicatedly reflected localized differences in the vicinity of rebar and concrete.These findings,along with the progressively ongoing research,will provide valuable information in structural durability for service life prediction of reinforced concrete structures exposed to marine environments.