Effects of Coating/Electroplating on Corrosion Resistance of Steel Bar in Reinforced Concrete

2012 ◽  
Vol 446-449 ◽  
pp. 3176-3179 ◽  
Author(s):  
Qun Zhou ◽  
Zhong He Shui ◽  
Yi De Xiao ◽  
Chang Sheng Xu
Keyword(s):  
Corrosion Resistance ◽  
Reinforced Concrete ◽  
Surface Treatment ◽  
Equivalent Circuit ◽  
Surface Coating ◽  
Corrosion Process ◽  
Steel Bar ◽  
Study Results ◽  
Steel Bars ◽  
Corrosion Of Steel

One of the main reasons for the damage of reinforced concrete is the expansion caused by corrosion of steel bar in concrete. In this paper, the equivalent circuit that inflects corrosion process of steel bars in reinforced concrete was analyzed, with the A.C.Impedance Spectrum method. And the effects of surface treatment of the bars on corrosion resistance of the reinforced concrete were investigated. Study results show that the surface coating (plating) on the built-in reinforcement can effectively prevent corrosion of steel bar, thereby enhancing the durability of concrete structures.

scholarly journals Study on the potential change of corroded reinforced concrete in ECE with MPC-CFRP as anode

2020 ◽  
Vol 319 ◽  
pp. 06005
Author(s):  
Yue Li ◽  
Xiuhu Zhang ◽  
S.M.Ali S. Hejazi
Keyword(s):  
Composite Material ◽  
Reinforced Concrete ◽  
Current Density ◽  
Good Effect ◽  
Steel Bar ◽  
Steel Bars ◽  
Cfrp Composite ◽  
Current Densities ◽  
Electrochemical Chloride Extraction ◽  
Corrosion Of Steel

Aiming at the rust removal requirements of reinforced concrete, the MPC-CFRP composite material was used as the external anode, and the Electrochemical chloride extraction (ECE) method was used to test the polarization curve of the steel bar under different ECE current densities, and the potential changes of the steel bar at different times were analyzed. The results show that the ECE system with MPC-CFRP as the external anode has a good effect of reducing the corrosion rate and the risk of corrosion of steel bars. The current density of 3A/m2is higher than that of 1A/m2in dechlorination efficiency. After 28 days of ECE, the current density of 1A/m2and 3A/m2can re passivate the reinforcement.

scholarly journals Relationship model between surface strain of concrete and expansion force of reinforcement rust

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fanxiu Chen ◽  
Zuquan Jin ◽  
Endong Wang ◽  
Lanqin Wang ◽  
Yudan Jiang ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Real Time ◽  
Steel Corrosion ◽  
Surface Strain ◽  
Concrete Cracking ◽  
Whole Process ◽  
Steel Bars ◽  
Relationship Model ◽  
Expansion Force ◽  
Corrosion Of Steel

AbstractConcrete cracking caused by corrosion of reinforcement could significantly shorten the durability of reinforced concrete structure. It remains critical to investigate the process and mechanism of the corrosion occurring to concrete reinforcement and establish the theoretical prediction model of concrete expansion force for the whole process of corrosion cracking of reinforcement. Under the premise of uniform corrosion of reinforcing steel bars, the elastic mechanics analysis method is adopted to analyze the entire process starting from the corrosion of steel bars to the cracking of concrete due to corrosion. A relationship model between the expansion force of corrosion of steel bars and the surface strain of concrete is established. On the cuboid reinforced concrete specimens with square cross-sections, accelerated corrosion tests are carried out to calibrate and verify the established model. The model can be able to estimate the real-time expansion force of reinforced concrete at any time of the whole process from the initiation of steel corrosion to the end of concrete cracking by measuring the surface strain of concrete. It could be useful for quantitative real-time monitoring of steel corrosion in concrete structures.

Test and Study on Impact of Corrosion on Bond Force between Steel and Concrete

2010 ◽  
Vol 36 ◽  
pp. 176-181
Author(s):  
Xian Feng He ◽  
Shou Gang Zhao ◽  
Yuan Bao Leng
Keyword(s):  
Reinforced Concrete ◽  
Corrosion Rate ◽  
Concrete Structure ◽  
Steel Corrosion ◽  
Reinforced Concrete Structure ◽  
Bond Force ◽  
Steel Bars ◽  
Protection Layer ◽  
Corrosion Of Steel ◽  
The Impact

The corrosion of steel will have a bad impact on the safety of reinforced concrete structure. In severe cases, it may even be disastrous. In order to understand the impact of steel corrosion on the structure, tests are carried out to study corrosion and expansion rules of steel bars as well as the impact rules of corrosion on bond force between steel and concrete. The results show that wet and salty environment will result in steel corrosion; relatively minor corrosion will not cause expansion cracks of protection layers; when steel rust to a certain extent, it will cause cracks along the protection layer; when there exists minor corrosion in steel and the protection layer does not have expansion cracks, the bond force is still large and rapidly decreases as the corrosion rate increases.

Research of the Surface Treatment Process of Bonded NdFeB Magnet with Composite Powder Electrostatic Spraying

2018 ◽  
Vol 278 ◽  
pp. 63-71 ◽  
Author(s):  
Kai Ye Xiao ◽  
Hai Xu ◽  
Zhi Wei Guo ◽  
Wen Zheng
Keyword(s):  
Corrosion Resistance ◽  
Surface Treatment ◽  
Surface Coating ◽  
Composite Powder ◽  
Treatment Process ◽  
Ndfeb Magnet ◽  
Treatment Technology ◽  
Electrostatic Spraying ◽  
Strong Adhesion ◽  
Epoxy Paint

Compared with the traditional air spraying technique and electroplate method, the coating defects of bonded NdFeB magnet, such as the workpiece hanging point, the pinhole, the bubble, have been solved by using the composite powder electrostatic spraying as surface treatment technology, along with the EE epoxy paint as primer coating and PU polyurethane paint as surface coating. The coating of this composite powder electrostatic spraying is uniform and compact, and the coating has strong adhesion and corrosion resistance. This paper gives a detailed introduction to the composite powder electrostatic spraying, including the choice of some important parameters and the unique hanging tools of composite powder electrostatic spraying.

scholarly journals Effect of Imidazoline Inhibitor on the Rehabilitation of Reinforced Concrete with Electromigration Method

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 398 ◽  
Author(s):  
Chonggen Pan ◽  
Jianghong Mao ◽  
Weiliang Jin
Keyword(s):  
Reinforced Concrete ◽  
Extraction Efficiency ◽  
Corrosion Potential ◽  
Steel Bar ◽  
Chloride Migration ◽  
Significant Difference ◽  
Steel Bars ◽  
Novel Method ◽  
Electrochemical Chloride Extraction ◽  
High Chloride

Steel bars embedded in reinforced concrete are vulnerable to corrosion in high chloride environments. Bidirectional electromigration rehabilitation (BIEM) is a novel method to enhance the durability of reinforced concrete by extracting chloride out of concrete and introducing an inhibitor to the surface of the steel bar under the action of an electric field. During the migration process, a higher ionization capacity of the inhibitor with a symmetrical molecular structure was introduced. A new imidazoline inhibitor was, therefore, employed in this study due to its great ionization capacity. The effect of imidazoline and triethylenetetramine inhibitor on chloride migration, corrosion potential, and strength of concrete were explored. The research results showed that the effect of chloride extraction and electrochemical chloride extraction made no significant difference on the surface of the concrete, where chloride extraction efficiency was more than 70%, and the chloride extraction efficiency was more than 90% around the location of the steel. while a dry-wet cycle test, the potential of concrete increased by about 200 mV by mixing imidazoline inhibitor. The imidazoline inhibitor was found to be effective at facilitating chloride migration and ameliorating corrosion, meanwhile, it had a negligible impact on the concrete’s strength.

scholarly journals Chemical Composition of Corrosion Products of Rebar Caused by Carbonation and Chloride

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Jundi Geng ◽  
Junzhe Liu ◽  
Jiali Yan ◽  
Mingfang Ba ◽  
Zhimin He ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Corrosion Products ◽  
Chloride Salt ◽  
Oxide Content ◽  
Passivation Film ◽  
Steel Bar ◽  
Steel Bars ◽  
Main Components ◽  
Corrosion Of Steel ◽  
Peak Value

The microstructures of steel bars were studied by X-ray photoelectron spectroscopy (XPS), and the mechanism of corrosion of steel bars under the corrosion factors was elucidated. The results show that the passivation film and corrosive surface of the steel surface in the solution of the chloride-containing salt were coarser and the surface state was denser. The main corrosion products are FeOOH and FeO. The surface of the steel immersed in the simulated carbonized solution had loose pores. The main components are FeOOH, Fe3O4, and Fe2O3. The surface of the steel bar has a large amount of yellowish brown corrosion products in the simulated carbonization and chloride salt. The surface of the corrosion products was stripped and the main components are FeOOH, Fe3O4, and FeCl3, where the content of FeOOH is as high as 60%. The peak value of iron is gradually increased from the simulated chloride salt solution to the carbonized solution to the combined effect of carbonation and chloride salt; the iron oxide content is increased and corrosion of steel is obviously serious.

The Study of Fuzzy Reliability of Concrete Durability after Corrosion of Steel-Bars

2011 ◽  
Vol 291-294 ◽  
pp. 2159-2163
Author(s):  
Yang Hang Shi ◽  
Lu Zhang ◽  
De Hai Yu
Keyword(s):  
Reinforced Concrete ◽  
Influencing Factors ◽  
Mathematic Model ◽  
Engineering Practice ◽  
Concrete Durability ◽  
Actual Situation ◽  
Fuzzy Probability ◽  
Fuzzy Reliability ◽  
Steel Bars ◽  
Corrosion Of Steel

Based on the mechanism, influencing factors and their fuzziness of reinforced concrete (RC) cracking caused by corrosion of steel bars, fuzzy reliability of RC durability failure due to corrosion expansion of steel bars is analyzed adopting the mathematic model of fuzzy probability. The method having the advantages of explicit concept, convenient calculation and stable results which is proved by the examples accords with the actual situation and can be applied to the engineering practice.

Wave amplitude of embedded ultrasonic transducer-based damage monitoring of concrete due to steel bar corrosion

2021 ◽  
pp. 147592172110417
Author(s):  
Shunquan Zhang ◽  
Zijian Jia ◽  
Yuanliang Xiong ◽  
Ruilin Cao ◽  
Yamei Zhang ◽  
...  
Keyword(s):  
Ultrasonic Transducer ◽  
Steel Corrosion ◽  
Galvanic Current ◽  
Cell Potential ◽  
Accelerated Corrosion ◽  
Electrochemical Testing ◽  
Steel Bar ◽  
Steel Bars ◽  
Damage Process ◽  
Corrosion Of Steel

In this research, four embedded ultrasonic piezoelectric transducers were combined to form cross pair and opposite pair monitoring schemes for continuously monitoring the damage to different strength grades of concrete caused by the corrosion of reinforcements under accelerated corrosion conditions. The damage process was analyzed by combining the electrochemical effects of steel corrosion, that is, half-cell potential and galvanic current tests. Results show that the embedded ultrasonic transducer method can detect damage of concrete during steel corrosion and that each stage of damage can be determined from the plots of ultrasonic transducer data versus corrosion rate. The results further indicate that a combination of cross pair and opposite pair testing methods can more comprehensively reflect the damage to concrete caused by the expansion of corrosion of steel bars, than a single testing method. Since electrochemical testing can only depict the corrosion state of steel rebars, it is beneficial to use embedded ultrasonic measurements to monitor the damage process of concrete. The differences in damage between different strength grades of concrete, that is, the resistance to corrosion of steel bars and brittle failure, can be obtained from the plots of ultrasonic transducer data.

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