scholarly journals Macrocell Corrosion of Steel in Concrete under Carbonation, Internal Chloride Admixing and Accelerated Chloride Penetration Conditions

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7691
Author(s):  
Zhilu Jiang ◽  
Siyao Li ◽  
Chuanqing Fu ◽  
Zheng Dong ◽  
Xuefeng Zhang ◽  
...  
Keyword(s):  
Corrosion Rate ◽  
Steel Corrosion ◽  
Chloride Penetration ◽  
Localized Corrosion ◽  
Geometrical Parameters ◽  
Correction Coefficient ◽  
Two Dimensional ◽  
Steel Bar ◽  
Corrosion Of Steel ◽  
Macrocell Corrosion

Steel corrosion has become the main reason for the deterioration of reinforced concrete structures. Due to the heterogeneity of concrete and the spatial variation of environmental conditions, macrocell corrosion is often formed by localized corrosion, which is more detrimental if the anode is supported by large numbers of cathodes. The macrocell corrosion caused by concrete carbonation has been seldom studied. Furthermore, the influence of geometrical conditions on cathode-controlled corrosion in the chloride environment needs to be further clarified. In this work, the macrocell corrosion of steel embedded in concrete specimens exposed to accelerated carbonation, chloride contamination, and chloride penetration is studied using a modified ASTM G109 method. Concrete specimens with various binder types, geometrical parameters (i.e., concrete cover thickness and the diameter of embedded steel), and boundary conditions were tested. A simplified mathematical model for the prediction of the steel corrosion rate was developed considering two-dimensional oxygen diffusion. The results showed that, at the same level of anodic potential drops, the corrosion current rate in chloride-induced corrosion is higher than that of carbonation-induced corrosion. Chloride contamination is less detrimental to concrete incorporated with slag and pulverized fly ash than it is to pure ordinary Portland cement (OPC), likely due to enhanced chloride binding capacity. The results also indicated that the model considering two-dimensional diffusion can accurately predict the cathodic reaction process on corroded steel bars, which provides a theoretical basis for considering the correction coefficient of steel bar position in the establishment of a steel bar corrosion rate model.

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.

The Calculation of the Thickness for Uniform Corrosion and Localized Corrosion in Steel Corrosion

2011 ◽  
Vol 255-260 ◽  
pp. 514-518
Author(s):  
Zheng Yi Kong ◽  
Shan Hua Xu ◽  
Yu Sheng Chen
Keyword(s):  
Corrosion Rate ◽  
Constant Temperature ◽  
Safety Assessment ◽  
Steel Corrosion ◽  
Localized Corrosion ◽  
Power Relationship ◽  
Uniform Corrosion ◽  
Experiment Data ◽  
Temperature And Humidity ◽  
Corrosion Pits

Because of the complexity of corrosion, the law of uniform corrosion and localized corrosion is still not clear,so it is difficult to assess their impact on the structure safety. In order to differ them and find their own law, we obtain a lot of corrosion specimens by ways of constant temperature and humidity, and then detect the size of corrosion pits by roughness tester. After that, the method for calculating the thickness of uniform corrosion and localized corrosion is proposed. Then the method is used to analyze the experiment data. The result indicates the thickness of uniform corrosion and localized corrosion all increase with the rate of corrosion, and they all show a power relationship with corrosion rate, so it will provide a basis for distinguishing them in safety assessment.

scholarly journals Galvanic Corrosion Due to a Heterogeneous Sulfate Reducing Bacteria Biofilm

Coatings ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1116
Author(s):  
Hongwei Liu ◽  
Haixian Liu ◽  
Yuxuan Zhang
Keyword(s):  
Galvanic Corrosion ◽  
Steel Corrosion ◽  
Localized Corrosion ◽  
Cathodic Reaction ◽  
Anodic Reaction ◽  
Sulfate Reducing ◽  
Corrosion Effect ◽  
Desulfotomaculum Nigrificans ◽  
Corrosion Of Steel ◽  
Reducing Bacteria

In this work, the galvanic corrosion behavior of sulfate reducing Desulfotomaculum nigrificans biofilm-covered and uncovered carbon steel was investigated using various electrochemical measurements. The results showed that the bare specimen in the abiotic solution functions as the anode; whereas the biofilm-covered specimen in the SRB-containing solution functions as the cathode after two electrodes being coupled. The anodic reaction of specimen in the biotic solution containing SRB was inhibited; whereas the cathodic reaction was considerably promoted after coupling. Hence, localized corrosion of specimen in the abiotic solution was observed due to the galvanic corrosion effect. SRB could still accelerate steel corrosion even after coupling, but the results indicate that the contribution of SRB to steel corrosion decreased. The localized corrosion of steel in the SRB-containing environments not only involved the SRB biofilm, but also a galvanic corrosion effect. The flow of electrons from the anodic dissolution of Fe in the abiotic solution to the SRB cells of cathodic area decreased the acceptance capacity of electrons by SRB from steel beneath biofilm. As a result, the steel corrosion beneath SRB biofilm decreased after coupling.

All-Solid-State Reference Electrode Based on Polymer Composites for Corrosion Monitoring of Steel in Concrete

2010 ◽  
Vol 163-167 ◽  
pp. 2945-2948
Author(s):  
Li Juan Kong ◽  
Tong Zhang ◽  
Guang Pin Song
Keyword(s):  
Solid State ◽  
Civil Engineering ◽  
Reference Electrode ◽  
Steel Corrosion ◽  
Steel Structures ◽  
Electrode System ◽  
Corrosion Monitoring ◽  
Steel Bar ◽  
State Reference ◽  
Corrosion Of Steel

Corrosion of steel structures has been found to be a problem Corrosion can be managed but not eliminated, so detecting corrosion will remain an issue no matter how effective corrosion prevention programs become. Electrochemical reaction is the basically process of steel corrosion in civil engineering, so electrochemical method is the best way to monitor corrosion grade. Liquid state reference is often used in lab to study steel corrosion by triple electrode system, but it is very difficultly used in steel bar corrosion monitoring in civil engineering. Firstly, liquid reference’s life is, generally speaking, very short. The steel corrosion is a very slow process, corrosion monitoring should be tens of years, so the liquid reference’s life is not long enough for corrosion monitoring; Secondly, the reference electrode’s strength have to be very high. Obviously, liquid electrode reference can not meet the requirement. In this paper, a novel all solid state reference electrode (ASSRE) has been developed. There are three layers in the electrode. Four kinds of components have been included in first and second layer. Additional AgCl powder has been used to inhibit AgCl decrease which is on the surface of Ag wire by complexing effect. There is only one kind of component in third layer. There are four steps to prepare the reference electrode: electrolyze, pre-mixed components, modelling and sintering. Finally, the potential of ASSR has been measured by SCE.

scholarly journals Thin Benzotriazole Films for Inhibition of Carbon Steel Corrosion in Neutral Electrolytes

Coatings ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 362 ◽  
Author(s):  
Maxim Petrunin ◽  
Liudmila Maksaeva ◽  
Natalia Gladkikh ◽  
Yuriy Makarychev ◽  
Marina Maleeva ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Photoelectron Spectroscopy ◽  
Steel Surface ◽  
Steel Corrosion ◽  
Chloride Ions ◽  
Localized Corrosion ◽  
Polymeric Coatings ◽  
Carbon Steel Surface ◽  
Corrosion Of Steel ◽  
Anticorrosion Properties

This article investigates the modification of a carbon steel surface by benzotriazole (BTA), and the structure and properties of the formed layers. Adsorption was studied by surface analytical methods such as X-ray photoelectron spectroscopy (XPS) and reflecting infrared microscopy (FTIR). It has been established that a polymer-like film containing iron-azole complexes that are 2 nm thick and strongly bonded to the metal is formed on the surface as a result of the azole interacting with a steel surface. This film is capable to inhibit uniform and localized corrosion of steel in neutral aqueous electrolytes containing chloride ions. It is shown that the iron-azole layer located at the interface acts as a promotor of adhesion, increasing the interaction of polymeric coatings with the steel surface. Taking into account these properties, the steel pretreatments can be used for improving the anticorrosion properties of polymeric coatings applied for the protection of steel constructions.

Effect of Migrating Corrosion Inhibitor on Corrosion Rate of Reinforcing Steel in Concrete with Various Admixed Chloride

2012 ◽  
Vol 204-208 ◽  
pp. 3146-3150 ◽  
Author(s):  
Zhi Yong Liu ◽  
Xin Gang Zhou ◽  
Xiu Lin Li
Keyword(s):  
Corrosion Rate ◽  
Electrochemical Impedance ◽  
Corrosion Current ◽  
Cementitious Materials ◽  
Steel Bar ◽  
Average Corrosion Rate ◽  
Corrosion Of Steel ◽  
High Chloride ◽  
Effect Of Surface ◽  
Chloride Contaminated

Effect of surface applied inhibitor on the durability of chloride contaminated reinforced concrete has been investigated in this paper. The C30 concrete samples contaminated with 0.5%,1.0%,1.5% NaCl by mass of the cementitious materials in the mixing process were experienced adequate curing and subjected to 1 months exposure tests after painting with 400 g/m2 MCIs. The corrosion behavior of the steel rebar in concrete samples was monitored by using electrochemical impedance spectroscopy (EIS), linear polarization resistance (LPR) and corrosion currents. The results indicate that, after painting the MCIs for 28d on the surface of concrete samples with 0.5% and 1% NaCl, the average corrosion rate of reinforcements in concrete samples （0.34μA/cm2 ）is lower than that of the control one (No.0, no painted inhibitor), and about 1/4 of the initial corrosion current of the samples with 0.5% and 1% NaCl before painting MCI. But the corrosion current of rebar in No.3 sample with 1.5% NaCl is still higher than that of the control one (No.0). Therefore, painting MCIs on the surface of samples is very effective to inhibit the corrosion of steel bar in concrete at low or middle chloride conditions, but it is not enough to repair severely corroded steel bar in high chloride contaminated concrete.

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.

Influences of Concrete Resistivity on Corrosion Rate of Steel Bar in Concrete

2013 ◽  
Vol 438-439 ◽  
pp. 349-352
Author(s):  
Zhong Hui Huang ◽  
Bo Yu ◽  
Lu Feng Yang ◽  
Ming Wu
Keyword(s):  
Corrosion Rate ◽  
Current Density ◽  
Oxygen Diffusion ◽  
Residual Life ◽  
Steel Corrosion ◽  
Rc Structures ◽  
Macro Cell ◽  
Capacity Evaluation ◽  
Steel Bar ◽  
Concrete Resistivity

Corrosion rate of steel bar in concrete plays an important role in load bearing-capacity evaluation, maintenance decision and residual life prediction of existing RC structures. A macro cell corrosion model was developed to investigate the influences of concrete resistivity on corrosion rate of steel bar in concrete based on the electrochemical principle and the Bulter-Volmer equation. Analysis results show that concrete resistivity has significant effect on corrosion rate of steel bar in concrete if the limit current density is relative large and the steel corrosion is under control of ion transportation. With the increase of relative humidity, the limit current density decreases obviously and the steel corrosion is influenced by both oxygen diffusion and concrete resistivity. However, if the concrete resistivity is relative small, steel corrosion will be under control of oxygen diffusion.

Corrosion behavior of steel bar embedded in high-ductility cementitious composites under the coupled action of dry–wet cycles and chloride attack

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Li-Ping Guo ◽  
Li-Juan Chai ◽  
Yan-Hui Xu ◽  
Cong Ding ◽  
Yuan-Zhang Cao
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Steel Corrosion ◽  
High Ductility ◽  
Chloride Permeability ◽  
Content Type ◽  
Steel Bar ◽  
Chloride Attack ◽  
Structure Engineering

Purpose High-ductility cementitious composites (HDCC) have an excellent crack controlled capacity and corrosion resistance capacity, which has a promising application in structure engineering under harsh environment. The purpose of this study is to explore the corrosion mechanism of steel bar in HDCC. Design/methodology/approach Intact and the pre-cracked HDCC specimens under the coupled action of different dry–wet cycles and chloride attack were designed, and intact normal concrete (NC) was also considered for comparison. Corrosion behavior of a steel bar embedded in HDCC was analyzed by an electrochemical method, a chloride permeability test and X-ray computed tomography. Findings Steel corrosion probability is related to the chloride permeability of the HDCC cover, and the chloride permeability resistance of HDCC is better than that of NC. Besides, crack is the key factor affecting the corrosion of steel bars, and the HDCC with narrower cracks have a lower corrosion rate. Slight pitting occurs at the crack tips. In addition, the self-healing products and corrosion products fill up the cracks in HDCC, preventing the external aggressive ions from entering and thereby decreasing the steel corrosion rate. Originality/value HDCC has a superior corrosion resistance than that of NC, effects of variable crack width on corrosion behavior of steel bar in HDCC under the coupled actions of different dry–wet cycles and chloride attack are investigated, which can provide the guide for the design application of HDCC material in structure engineering exposed to marine environment.

Research on Carbon Steel Test Conducted by Means of Steady-Damp Heat Periodic Immersion Method

2012 ◽  
Vol 511 ◽  
pp. 78-82
Author(s):  
Dong Hao Li ◽  
Jun Hu ◽  
Ling Xia Li
Keyword(s):  
Carbon Steel ◽  
Corrosion Rate ◽  
Linear Correlation ◽  
Corrosion Test ◽  
Steel Corrosion ◽  
Accelerated Test ◽  
Immersion Method ◽  
Corrosion Of Steel ◽  
Corrosion Time

After analyzing the hazards of steel corrosion, the accelerated steel corrosion test conducted by means of steady-damp heat periodic immersion method (artificial accelerated test) is briefly introduced, and the result of the test is analyzed. It is indicated by the test that, the steady-damp heat periodic immersion method could significantly accelerate the corrosion of steel, and there is a linear correlation shown between the corrosion rate and corrosion time of steel.

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