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Copyright of Journal of Electronic Measurement & Instrument is the property of Journal of Electronic Measurement & Instrumentation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Corrosion is a phenomenon that occurs on pipes, reinforced concrete structures, and storage tanks and causes a major impact on the facility structures and can have a major impact on a facility's structural integrity. This can result in a serious failure in the system and lead to substantial economic losses. One of the solutions widely used to eliminate the corrosion effects is by applying cathodic protection, which depends on direct current as the supply potential. The technique of cathodic protection is used to control corrosion in the utilisation of reinforced concrete structures, pipelines, storage tanks, etc. A photovoltaic cathodic protection system is normally used as an energy source to supply the system. This research reviews the technique utilised for applying solar photovoltaics in powering systems of cathodic protection. Subsequently, it highlights the methods of cathodic protection systems, sacrificial anode cathodic protection and the impressed current cathodic protection. Finally, it is indicated that applying solar photovoltaics in powering cathodic protection systems has great efficacy in controlling the corrosion in the facility's equipment in a smarter, controlled way. Furthermore, this study provides significant insight into the designing and operating the domain of solar photovoltaic systems that power cathode protection systems. [ABSTRACT FROM AUTHOR]

In this study, a new anticorrosion method combining impressed current cathodic protection (ICCP) with coatings that can be applied to marine atmospheric environments is proposed. As the corrosion medium fills the cracks and pores of the coating, an electrolyte film layer is inevitably formed on the metal surface. Therefore, a graphene conductive coating with excellent chemical inertness and shielding performance is selected as the intermediate coating to form an electrolytic cell system with a metal substrate serving as the cathode and a graphene coating serving as the auxiliary anode. By studying the surface corrosion morphologies and electrochemical signals of the coating samples at different protection potentials and coating thicknesses, the optimal potential is determined to be 0.6 V, and the optimal coating thickness is determined to be 20 μm. The samples protected by the joint method have lower corrosion rates and better anticorrosion performance than those protected by the coatings alone. [ABSTRACT FROM AUTHOR]

Impressed current cathodic protection system in association with organic coatings is used for the protection of engineering structures such as buried pipe lines. However, the organic coating degrades with the function of time. Inherently or intrinsically conducting polymers have been emerged as promising materials for making anti-corrosion coatings on the active metals and alloys. In this work, epoxy, fusion bonded epoxy and conducting polyaniline based paints were applied on low carbon steel samples. Electrochemical studies was carried out using potentiodynamic polarization, open circuit potential measurements and electrochemical impedance spectroscopy in 3.5% NaCl solution. The corrosion rate of conducting polyaniline based painted low carbon steel by using platinum as a counter electrode was found to be 0.1 mpy which is about 82 times lower than uncoated low carbon steel, 9 times lower than epoxy coated low carbon steel and 6 times lower than fusion bonded epoxy coated low carbon steel. Conducting polyaniline coated low carbon steel samples offered higher impedance (Zmod), coating resistance (Rc), charge transfer resistance (Rct), lower coating capacitance (Cc) after 48 h of immersion in 3.5% NaCl solution without impressed current cathodic protection and under impressed current cathodic protection. [ABSTRACT FROM AUTHOR]

Offshore facilities, such as oil and gas rigs, wind turbines, and related subsea equipment, typically use flanges fastened using bolts and nuts as the main connectors. In this study, multidisciplinary parameters, namely the preload torque used to tighten bolts, simulated subsea water currents, water temperature, and impressed current cathodic protection, were applied to ASTM A193 B7 bolts. An experimental supervisory control and data acquisition system was designed to obtain measurements every 5 min throughout a 21-day experiment. Finite element analysis was performed to predict the structurally vulnerable areas of the bolts. A strong correlation was found between the reference electrode readings and the measured electrical current, tightening torque, and water temperature. As the water temperature rises during the day, the reference electrode reading becomes less negative and the electrical current decreases. Subsea water currents cause about a four-time increase in the bolt corrosion rate, with unprotected bolts suffering a nine-time-higher corrosion rate than protected bolts. A unique supply–demand interaction is observed; less protection is supplied to areas with lower corrosion rates (lower demand for protection). Finally, scanning electron microscopy examination reveals new insights into the failure mechanisms of subsea bolts.

钢管桩码头外加电流阴极保护系统处于严苛海洋腐蚀环境并面临台风侵袭, 系统设计在确保满足阴极保护 规范要求的同时, 还需重点关注各系统组件的长期耐久性能。基于湛江港某码头钢管桩外加电流阴极保护系统设计, 详细介绍了关键参数的决策过程, 包括电流计算中涂层破损率的取值、阴极保护电源的设计选型和布置以及布线系 统设计。5 a 的运行结果表明, 阴极保护系统设计整体上是成功的, 系统运行状态与设计意图基本符合。 [ABSTRACT FROM AUTHOR]

The cable system is an important bearing element of a bridge with stay cables or slings and a matter of major concern in the safety of the bridge structure. Bridge cables are vulnerable to corrosion induced by leakage and soaking during their service life. To solve this problem, and based on the idea of proactive control by means of the impressed current cathodic protection (ICCP) of bridge cables, this study designs and develops an ICCP system device for bridge cable protection. In this study, an accelerated corrosion test was conducted to test the ICCP system of steel wires inside the cables and the cables under acid rain conditions. The corrosion protection behavior of ICCP was analyzed to reveal the corrosion protection mechanism of bridge cable ICCP. The results show that in the cable ICCP system, the impressed current generated by a more negative voltage may improve the efficiency of corrosion protection, but an excessively negative voltage may cause hydrogen embrittlement of the cable steel wire due to overprotection. The rational range of −1.13 V to −1.15 V was set as the result of the overall consideration. Within this range, the cable is subject to the joint protection of ICCP and sacrificial anode cathodic protection (SACP). Corrosive products can delay the development of cable corrosion to a certain degree; the SACP protection efficiency of the galvanized coat reduces gradually with corrosion development; and cable ICCP protection efficiency increases gradually. The ICCP for cable corrosion protection is transformed from joint protection using both a sacrificial anode and impressed current into protection, mainly using an impressed current. [ABSTRACT FROM AUTHOR]

Copyright of Electroplating & Finishing is the property of Electroplating & Finishing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The cable system is an important bearing element of a bridge with stay cables or slings and a matter of major concern in the safety of the bridge structure. Bridge cables are vulnerable to corrosion induced by leakage and soaking during their service life. To solve this problem, and based on the idea of proactive control by means of the impressed current cathodic protection (ICCP) of bridge cables, this study designs and develops an ICCP system device for bridge cable protection. In this study, an accelerated corrosion test was conducted to test the ICCP system of steel wires inside the cables and the cables under acid rain conditions. The corrosion protection behavior of ICCP was analyzed to reveal the corrosion protection mechanism of bridge cable ICCP. The results show that in the cable ICCP system, the impressed current generated by a more negative voltage may improve the efficiency of corrosion protection, but an excessively negative voltage may cause hydrogen embrittlement of the cable steel wire due to overprotection. The rational range of −1.13 V to −1.15 V was set as the result of the overall consideration. Within this range, the cable is subject to the joint protection of ICCP and sacrificial anode cathodic protection (SACP). Corrosive products can delay the development of cable corrosion to a certain degree; the SACP protection efficiency of the galvanized coat reduces gradually with corrosion development; and cable ICCP protection efficiency increases gradually. The ICCP for cable corrosion protection is transformed from joint protection using both a sacrificial anode and impressed current into protection, mainly using an impressed current.

Impressed current cathodic protection (ICCP) was widely applied for the corrosion control of reinforced concrete. During the ICCP treatment, the anodic reactions happened on the primary anode surface may induce acidification and subsequently pH drop in the vicinity of the anode, leading to damage of the external anode mortar. In this study, the relationship between the applied current (simulating ICCP treatment) on the Ti mesh anode and pH alterations in simulated concrete pore (SCP) solution (with/without chlorides) was investigated. It was found that the applied current slightly reduced the corrosion resistance of Ti mesh; this negative effect was more pronounced in the presence of chlorides. The pH value of SCP solution near Ti mesh anode decreased when the external current was applied. The consumption rate of OH– ion was higher in the chloride-containing SCP solution. A mathematical model was proposed between the electric charge quantity (Q) and OH– concentration (cOH–) in SCP solution near Ti mesh anode. This model is a useful tool to quantitatively identify the acidification damage induced by impressed current from the perspective of pH alternation near Ti mesh anode.

Copyright of Journal of Petroleum Research & Studies is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper presents a new mitigation proposal to the AC corrosion in the metallic pipeline due to its interference with transmission lines (TLs) based on inserting the polarization cell (KOH-PC), and fuzzy logic controller (FLC) along the pipeline. Impressed current cathodic protection (ICCP) confirmed to be an appropriate technique to control AC corrosion. The approval of corrosion protection widely relies on the distribution of DC voltage along the route of the pipeline. This study aims to achieve the optimum DC voltage distribution. Finally, this paper will be useful in the improvement of cathodic protection performance, especially with the presence of KOH-PCs. [ABSTRACT FROM AUTHOR]

Copyright of Journal of National University of Defense Technology / Guofang Keji Daxue Xuebao is the property of NUDT Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

• Development of a dual-functional intervention method for reinforced concrete beams. • Experimental programme on simply supported beams repaired by ICCP-SS method. • Analysis on the structural responses of simply supported beams with C-FRCM strengthening. • Comparison of test results with existing design methods. • Recommendation of changes on the design methods for cross-section capacity prediction. Chloride ions in marine environment can cause corrosion of steel reinforcement in reinforced concrete (RC) structures and result in structure deterioration. This study investigates a dual-functional intervention method, i.e. impressed current cathodic protection – structural strengthening (ICCP-SS) method, using carbon fibre reinforced polymer (CFRP) as both the anode material for impressed current cathodic protection and strengthening material for structural strengthening system. The effectiveness of the ICCP-SS method on the improvement of durability of RC structures is considered in a long-term timeframe. An experimental programme comprising nine simply supported beams is presented in this paper. The beams experienced 360-day accelerated corrosion and 180-day cathodic protection, followed by four-point bending tests. Flexural behaviour and capacities of the degraded beams repaired by using ICCP technology, structural strengthening technology and ICCP-SS technology were obtained. After the tests, the steel reinforcement bars inside concrete were taken out and cleaned to measure the section reduction due to corrosion. Results showed that the ICCP-SS technology can prevent the corrosion of the steel reinforcement effectively and increase the capacities of the beams at the same time. Finally, the appropriateness of existing design approaches for the intervened beams was also discussed in the paper. The ICCP-SS intervention method is found to be beneficial for the durability of RC structures in marine environment. [ABSTRACT FROM AUTHOR]

In the present work, the efficiency of the Impressed Current Cathodic Protection (ICCP) applied to reinforced concretes is investigated. A comprehensive approach, combining experimental and numerical methodologies, is employed. The investigation focuses on a simplified system, represented by a reinforced concrete slab subjected to accelerated corrosion. Experimental tests are conducted to evaluate the initial condition of the system and subsequently examine different ICCP scenarios. Various parameters are considered, including the spatial arrangement of reference electrodes and activated titanium anodes, as well as the applied current intensity. The outcomes of these experiments are carefully analyzed to assess the influence of these parameters, and the results are presented for in-depth discussion. Finally, a theoretical model based on electrochemical interactions between the steel and the concrete is developed thanks to virtual work principle. Applied to the system under study, the predictions of the model are shown to give satisfactory results when compared to experimental data, demonstrating its reliability. [Display omitted] • Investigation of ICCP process efficiency using experimental and numerical approaches. • Identification of key parameters in ICCP, including mask and distance effects. • Demonstration of anode location and applied potential impact on system response. • Model used to better assess the steel/concrete interface during cathodic protection. • Optimization techniques implemented to achieve model fit with experimental data. [ABSTRACT FROM AUTHOR]

• The feasibility of applying ICCP to chain structure was studied. • The conductivity was the key factor restricting the successful application of ICCP on the chain structure. • The 90-day corrosion rate of the ICCP-protected conductivity-improved chain reduced by 94.8%. • The quantitative formula of the relationship between the critical conductivity required for ICCP and the chain diameter was determined. Corrosion protection of mooring chain is difficult but of great significance to guarantee the security of deep-sea operation. In consideration of the advantages and limitation of impressed current cathodic protection (ICCP), the feasibility of ICCP application on chain structure was studied through physical experiments combining with COMSOL simulation. The influence of electrical continuity on the protection potential distribution was investigated by potential measurement and numerical simulation. It was demonstrated that the conductivity was the key factor restricting the successful application of ICCP on the chain structure. With improved electrical continuity, the surface potential distribution of the chain structure under ICCP was uniform with a difference less than 12 mV, and the 90-day corrosion rate significantly reduced by 94.8% compared with that without ICCP. Furthermore, the quantitative formula of the relationship between the critical conductivity required for ICCP and the chain diameter was determined to be σ c = 0.015 d 2 + 0.65 d + 10.49. The effect of corrosion time and auxiliary anode distance on the potential distribution was also investigated. This work might provide new idea for the corrosion protection of mooring chain and provide reference for the design of mooring chain with improved possibility in corrosion protection. [Display omitted] [ABSTRACT FROM AUTHOR]

Copyright of Matériaux et Techniques is the property of EDP Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Reinforced concrete (RC) stub columns are commonly featured in the construction industry, used in structures such as buildings and bridges. In coastal areas, bridge piers are subjected to serious corrosion damage, which may result in safety issues and huge economic losses. Currently, one of the most widely used retrofitting methods is the application of fiber reinforced polymer (FRP) sheets. This strengthening method can effectively improve the column capacities. However, as time goes by, the corrosion of re-bars will continue, leading to less force resistance. Impressed current cathodic protection (ICCP) is a well-known, efficient method to prevent further corrosion of the re-bars. Therefore, this study uses both ICCP and structural strengthening (SS) techniques to strengthen corroded RC columns. An experimental program consisting of 10 stub columns was carried out, including a 100-day accelerated corrosion process and 100-day ICCP protection and compression tests. Results show that the proposed ICCP-SS retrofitting method is not only effective in retarding the corrosion of steel but also capable of recovering the compression capacity of the corroded RC columns. In addition, comparisons between the test results and the predictions for RC column strengths by existing international design codes are made. The existing design methods were found to be conservative for the compression design of retrofitted columns. [ABSTRACT FROM AUTHOR]

Storage tanks condition and integrity is maintained by joint application of coating and cathodic protection. Iraq southern region rich in oil and petroleum product refineries need and use plenty of aboveground storage tanks. Iraq went through conflicts over the past thirty five years resulting in holding the oil industry infrastructure behind regarding maintenance and modernization. The primary concern in this work is the design and implementation of cathodic protection systems for the aboveground storage tanks farm in the oil industry. Storage tank external base area and tank internal surface area are to be protected against corrosion using impressed current and sacrificial anode cathodic protection systems. Interactive versatile computer programs are developed to provide the necessary system parameters data including the anode requirements, composition, rating, configuration, etc. Microsoft-Excel datasheet and Visual Basic.Net developed software were used throughout the study in the design of both cathodic protection systems. The case study considered in this work is the eleven aboveground storage tanks farm situated in al-Shauiba refinery in southern IRAQ. The designed cathodic protection systems are to be installed and monitored realistically in the near future. Both systems were designed for a life span of (15-30) years, and all their parameters were within the internationally accepted standards.

This research is devoted to design and implement a Supervisory Control and Data Acquisition system (SCADA) for monitoring and controlling the corrosion of a carbon steel pipe buried in soil. A smart technique equipped with a microcontroller, a collection of sensors and a communication system was applied to monitor and control the operation of an ICCP process for a carbon steel pipe. The integration of the built hardware, LabVIEW graphical programming and PC interface produces an effective SCADA system for two types of control namely: a Proportional Integral Derivative (PID) that supports a closed loop, and a traditional open loop control. Through this work, under environmental temperature of 30°C, an evaluation and comparison were done for two types of controls tested at low soil moisture (48%) and high soil moisture (80 %) to study the value of current, anode voltage, pipe to soil potential (PSP) and consumed power. The results show an decrease of 59.1% in consumed power when the moisture changes from the low to high level. It was reached that the closed loop controller PID is the best solution in terms of efficiency, reliability, fast response and power consumption.

The inductive coupling between high‐voltage power lines (HVPL) and buried pipelines has been an important research subject over the last decades. This coupling may result in alternating current (AC) on pipelines that may pose a serious threat to the pipelines due to corrosive effects and the cathodic protection (CP) performance. A method to investigate the effects of the induced AC density on the corrosion and the CP performances of the X70 steel buried pipeline due to the inductive interference caused by HVPL is proposed in this study. The method is based on the corrosion parameters of the X70 steel pipeline obtained by electrochemical measurements such as Tafel slopes, corrosion current densities, and corrosion potentials. These parameters were used as boundary conditions in the elaborated CP model. The results showed that, firstly, the induced AC density affects the electrochemical characteristic of the X70 steel and accelerates the corrosion of the pipeline. On the other hand, the impressed current cathodic protection is incapable of maintaining the CP potential level. However, some technical solutions were proposed to prevent the pipelines from AC corrosion and maintain the CP potential to an acceptable level. [ABSTRACT FROM AUTHOR]

Corrosion of reinforcing steel is the primary degradation mechanism by which the long-term durability of RC structures can be seriously impaired. In order to mitigate reinforcement corrosion, impressed current cathodic protection (ICCP) is becoming an interesting option to be used in practice on real structures. In this study, the electrical field distribution of ICCP systems for RC structures with complicated geometry and multiple corrosion boundaries is investigated by using a finite-element method (FEM) numerical simulation method. The numerical optimization scheme for ICCP to control corrosion of RC structures is developed by tuning the amplitude of the impressed voltage, as well as the location and area size of the anode layer. Two prototypes of ICCP systems for RC structures are built to verify the effectiveness of the optimization algorithm under laboratory conditions. The testing results indicate that this optimization design scheme of ICCP systems can effectively control the corrosion of RC structures with multiple boundary conditions. [ABSTRACT FROM AUTHOR]

Carbon fiber-reinforced polymer (CFRP) is recognized as a promising anode material to prevent steel corrosion in reinforced concrete. However, the electrochemical performance of CFRP itself is unclear. This paper focuses on the understanding of electrochemical and mechanical properties of CFRP in an oxygen evolution environment by conducting accelerated polarization tests. Different amounts of current density were applied in polarization tests with various test durations, and feeding voltage and potential were measured. Afterwards, tensile tests were carried out to investigate the failure modes for the post-polarization CFRP specimens. Results show that CFRP specimens had two typical tensile-failure modes and had a stable anodic performance in an oxygen evolution environment. As such, CFRP can be potentially used as an anode material for impressed current cathodic protection (ICCP) of reinforced concrete structures, besides the fact that CFRP can strengthen the structural properties of reinforced concrete. [ABSTRACT FROM AUTHOR]

Impressed current cathodic protection (ICCP) has been verified to be an effective method to control the corrosion of reinforced concrete (RC) structures, and the use of numerical simulation methods has become a powerful technique to investigate ICCP systems. This paper presents a numerical optimization method to design an economical and effective ICCP system for RC structures. First, the numerical model of the ICCP electrical field is built. The potential of the reinforcing steel and service life of the ICCP system are constrained by the protection potential in BS 12696:2012 and the life expectancy of the RC structure to be protected, and the accurate design parameters of the ICCP system, for example, the location and area of the anode overlay and the amplitude of the output voltage, are obtained by minimizing the total cost of the ICCP system. Finally, a small-scale RC T-shaped beam is adopted as an example to illustrate the numerical optimization method, and corresponding prototypes are developed to verify the corrosion control effect of the numerically optimized ICCP system. [ABSTRACT FROM AUTHOR]

Engineering design calculations for tank bottom sections, including direct current requirements and voltage calculations, followed by additional structures, such as electrical grounding systems, have already been successfully implemented and controlled in field conditions. Furthermore, the effect of soil resistivity in layers, oxygen content and the pH value of the soil against the disproportionate IR-Drop voltage, including its effect on potential distribution, have been already successfully observed. Other influences, such as the depth and location of the anode groundbed determination along with the establishment of impressed current cathodic protection related to the main tools and equipment, such as external corrosion control methods, have been defined as the most effective ways in order to control potential distribution against the additional structures. Persuant to the verification results from the site located at Marangkayu, East Borneo, it has been determined that high soil resistivity could cause error readings in accordance with the accumulation results of the true readings and the IR-Drop voltage, since under real conditions, the tank structure would have received less current flow from an anode compared to a lower result. Naturally, a low pH value from the soil would decrease soil resistivity and enhance potential distribution from the anodes to the tank structures. The results show that the cathodic protection required 10 additional anodes, (each one is of a tubular mixed metal oxide) with a DC supply at minimum amperage of 154 Amps and a minimum voltage supply of 32 Volts. During the research, it was identified that high soil resistivity above 3000 ohm-cm would cause error readings. Naturally, acidic soil is in the region of pH 5-7 value, which would decrease soil resistivity and enhance the potential distribution from the anode to the tank structure. [ABSTRACT FROM AUTHOR]

In order to improve corrosion protection effect of semi-submersible crane vessel (SSCV), 3-D boundary element method combined with automatic movement of anodes and adjustment of currents is developed to optimize anode quantity, location and output current of impressed current cathodic protection system for SSCV. Numerical simulation results show that protection potential of SSCV is obviously smoothed after optimization. The protection effect of SSCV in four different states is also predicted and simulation results indicate that SSCV is well protected in the whole service life when the protective coating on hull is repainted every seven years. Finally, challenges associated with cathodic protection providing for marine engineering equipment are discussed. [ABSTRACT FROM AUTHOR]

Carbon-based conductive coatings are complex composites, consisting of an organic or inorganic binder and conductive carbon components, for application as anodes in impressed current cathodic protection systems of reinforced concrete structures. The electrochemical properties of three coatings at different humidity and in saturated calcium hydroxide solution were studied by electrochemical methods, such as electrochemical impedance measurement, measuring of open circuit potential over time and galvanostatic polarization. The dissolved organic and inorganic carbons in electrolyte solution were quantified by using a photometric method. The structures of the coatings were investigated before and after the electrochemical tests by microscopy and scanning electron microscope/EDX analysis. The results of the electrochemical impedance measurements show that the tested coatings all have a relatively low resistance, which is between 100 and 200V. The binder and the surface porosity influence the degradation behavior of those coatings. Especially the organic binder reacts with the strong alkaline medium under dissolving of organic carbon. [ABSTRACT FROM AUTHOR]

Purpose -- The purpose of the paper was to design an anti-corrosion system that combined conductive coatings with cathodic protection for a 500-kV substation ground grid, and provide a basis for the anti-corrosion construction of the installation. Design/methodology/approach -- The study took the Shaoguan 500-kV substation grounding grid as the research object. The anti-corrosion performance of KV conductive coatings on grounding metal was researched. In parallel, the alkalinity of substation soil was evaluated according to the German DIN50929 Standard, and the combined protection system comprising conductive coatings and impressed current cathodic protection was designed. Findings -- KV conductive coatings, that have resistance to acids, alkalis and salts, can effectively slow down the corrosion rate of the grounding grid. The investigation also provided the outline design, installation, construction requirements and monitoring methods for the 500-kV substation grounding grid. Originality/value -- This report contains some guiding significance for anti-corrosion engineering of 500-kV substation grounding grids. [ABSTRACT FROM AUTHOR]

A flexible anode and three graphite anodes were used to study cathodic protection in simulated grounding grid in the laboratory. The protection potential values and uniformities of these anodes were investigated under the same condition through potential detection at each grid node. The results showed that with flexible anode, the protection potential was 0·3 V less than that with graphite anode, the potential dispersion degree of each node was 0·1 times that with graphite anode, and no special demands were needed for the cathodic access points under the same condition. The potential dispersion degree of each node in grounding grid was influenced significantly by the cathodic access points when graphite was used as deep-well anode. The rational choice for cathode access points and increasing the depth of deep-well anode could decrease the potential differences and dispersion degree of each node. The impressed potential for realising the same protection potential with graphite anode was higher than that with flexible anode. [ABSTRACT FROM AUTHOR]

Abstract: Cathodic protection (CP) is an electrochemical repair technique that has increasingly been used for the repair of reinforced concrete structures in the UK and worldwide. Cathodic protection generally works by the passing of a small electrical current from the anode to the corroding steel reinforcement thereby protecting it from further deterioration by increasing the hydroxyl ions locally. This paper has looked at the advantages and disadvantages of using the two types of cathodic protection systems, namely sacrificial anode and impressed current CP, and highlighted some of the design considerations and challenges faced on a number of case histories that Mouchel have undertaken. From our experience the decision whether to use an impressed current CP system or a sacrificial anode CP system is influenced by a number of factors including but not limited to the condition (the level and extent of deterioration) of the structure, the client’s budget and the anticipated life expectancy of the structure following the repairs. Experience at Mouchel indicates that the circumstances where SACP is most suitable includes small and targeted repairs, repairs where budget costs are limited and repairs where the life expectancy is anticipated to be around 10years. On the other hand, ICCP is generally used to address significant corrosion problems to large structures and surface areas, where life expectancy is expected to be more than 25years and where access and traffic management are challenging and very costly. [Copyright &y& Elsevier]

Abstract: The magnitude of ship’s corrosion related electro-magnetic field was significantly influenced by the electrode positions and output current of the impressed current cathodic protection (ICCP) system. In order to minimize corrosion related electro-magnetic field, we must know how the electrode position and output current influence the strength of corrosion related electro-magnetic field. In this paper, the corrosion related electro-magnetic field was simulated by boundary element method (BEASY software) with different electrode position and output current, and then the influence of electrode position and output current on corrosion related electro-magnetic field was analyzed, last the optimized electrode position was ascertained. [Copyright &y& Elsevier]

Selection of an electrically remote location of an anode ground-bed with respect to its cathodic-protected pipeline and nearby foreign pipelines/structures is an important element of the design of impressed current cathodic protection systems. Proper understanding of commonly available and used practices is essential for selecting electrically remote locations of impressed current anode groundbeds. To facilitate proper design and evaluation of anode groundbeds of impressed current cathodic protection systems for cross-country pipelines, this paper contains a comprehensive review of commonly used practices and presents an improved technique for the calculation of earth potentials for the determination of remoteness of impressed current anode groundbeds. [ABSTRACT FROM AUTHOR]

A 1: 100 physical scale model of a vessel is established and used to study the distribution of the potential in the impressed current cathodic protection (ICCP) system of a hull's double-zones. The optimized design as below is obtained based on the experimental results of the 1 : 100 physical model. Two anodes are added to the bow area and reference electrode (RE) is fixed between two anodes, and RE is outside the anodes in the buttock area. Under the optimization operational condition, the potential range along the surface of the hull is between -- 0. 80 V and -- 0. 90 V, which provides adequate corrosion protection to the hull of the vessel. When the shaft is earthed, the potential around anodes reduces, and decreases with the increase of shaft's rotation rate. The optimized double-zones ICCP system can provide adequate corrosion protection of the vessel when the shaft is kept under different conditions. It is proved that the use of physical scale model provides a practical and flexible tool for the design and optimization of ICCP system of a ship. [ABSTRACT FROM AUTHOR]