Surface Of Steel Bar Research Articles

Experimental investigation on bond properties of nano-Al2O3 and hydroxypropyl methyl cellulose (HPMC) modified coated steel bar embedded in concrete

In this work, cementitious coatings incorporate nano-Al2O3 (NA) and HPMC were developed applying to the surface of steel bars to enhance bond behavior. A total of 81 pull-out specimens were prepared to evaluated bond properties of different coated steel bars embedded in ordinary performance concrete (OPC), high performance concrete (HPC) and ultra-high-performance concrete (UHPC). The mechanical properties of the cement-based coatings have also been examined. Test results show that flexural and compressive strengths of coating paste exhibited initially increasing and followed by decreasing as NA content increase. Synergistic effect of NA and HPMC results in cement-based coating exhibiting superior mechanical properties. Besides, coating microscopic morphology characterized by scanning electron microscope (SEM) technique revealed that fewer coating defects with NA and HPMC compounding. More importantly, the highest bond strength between coated steel bar and different types concretes was found at 1.0 % NA content in the coatings. Synergistic effect of 1.0 % NA and 0.12 % HPMC improved bond strength of coated steel bar embedded in OPC, HPC and UHPC. It can be obtained from bond-slip curve that, regardless of the HPMC addition to coatings, coated steel bar with 1.0 % NA content shows higher bond stiffness. With both NA and HPMC added, bond stiffness, bond toughness and bond ductility of coated steel bar are superior to those of the coating with NA alone. Moreover, as concrete strength increases, the bond strength, bond stiffness and bond toughness of coated steel bar also increase, respectively.

Chloride Resistance of Assembled Bridge Piers Reinforced with Epoxy-Coated Steel Bars

To reveal the influence of joint type and epoxy-coated steel bar surface damage on the durability of assembled bridge piers, this study simulated the potential damage to epoxy-coated steel bars at various stages of an actual construction process by bending, scratching, and knocking. The pier inter-segmental joint and the pier-bearing platform joint were designed to highlight the critical zones affecting the durability of sea-crossing bridge substructures. The migration of chloride ions into the concrete was accelerated by applying a constant voltage DC electric field. The electrochemical indexes of epoxy-coated steel bars and chloride ion content in concrete were measured regularly. Results show that the corrosion risk and corrosion rate of steel bars increase significantly when the damaged area ratio of epoxy coating is higher than 5%. The chloride ion transport rate at the interface of the pier-bearing platform joint is about 5 times that of the pier inter-segmental joint. The service life of the pier-bearing platform joint is only 1/2 that of the pier inter-segmental joint when epoxy-coated steel bars with the same treatment are used.

Walnut (Juglans regia L.) fruit septum alcoholic extract as corrosion inhibitor for Fe B500B steel bars in mixed acidic solution

The corrosion inhibition performance of the walnut fruit (Juglans regia L.) septum alcoholic extract for Fe B500B steel bars in a mixed acidic solution (H2SO4/HCl) is reported. Weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy measurements were performed at 298 to 318 K, with the addition of various extract concentrations. Results showed the maximum corrosion inhibition efficiency of 86.99 % for 300 mg L-1 extract added. The extract acts as a mixed-type inhibitor, predominantly affect­ing the anodic side, following Flory-Huggins adsorption isotherm. Thermodynamic analysis indicated an endothermic process with both chemisorption and physisorption on the steel bar surface. Surface characterization was conducted using ATR-FTIR, UV-vis and SEM techniques to prove the adsorption of the inhibitor molecules on the steel bar surface. Also, a possible adsorption mechanism of inhibitor molecules was proposed.

Facile route for processing natural polymers for the formulation of new low-cost hydrophobic protective hybrid coatings for carbon steel in petroleum industry

This research helps with the creation, assessment, and characterization of a new hybrid protective coating for carbon steel alloy in acid conditions. The findings of this study will be useful for both chemical and petrochemical companies as well as scientists. This study aims to protect C-steel in acid pickling solution 1.0M HCl and formulate new hydrophobic protective hybrid organic–inorganic coatings from biopolymers chitosan and plant resin guar gum. Eight coating samples of chitosan in the absence and the presence of guar gum, silica and two heterocyclic compounds are prepared at feasible operational conditions using hot melt method. The aiding additives improved compatibility between coating constituents as confirmed by using different methods of analysis. This new processing approach has addressed the problems of using chitosan in corrosion control such as solubility in acid media and low mechanical strength. Coating samples of chitosan and its composites with the heterocyclic compounds (2-Hydrazinyl-6-methyl-4, 5-dihydro pyrimidine-4-on) or (2-Hydrazinyl-6-phenyl-4, 5-dihydro pyrimidine-4-on) are potent biocides. Coating shifts corrosion potential of carbon steel by 30 mV to more noble direction relative to the active potential 520 mV of bare carbon steel surface. Impedance and polarization measurements indicate that coating samples protect metal surface as mixed-type inhibitor by adsorption mechanism. There is a good agreement between percentages protection %P of coating calculated using the values of charge transfer resistance, Rct, and corrosion current density, icorr. All %P values are above 99% for all coating samples. Guar gum plant resin increases gloss of the coating film. Silica fills the pores in the polymeric film and increases the stuffiness of the polymeric coating film by modifying the particle size. All coated samples have high contact angle ranging from 150° to 165° indicating low wettability and high hydrophobicity of coating film on the metal surface.

The synergistic anti‐corrosion performance and mechanism of meso‐tetra(4‐carboxyphenyl)porphine on steel bars in alkaline environments

AbstractCorrosion protection of steel bars in alkaline concrete environments poses a common challenge in marine engineering. One approach to mitigate steel bar corrosion is the addition of corrosion inhibitors to the concrete. In alkaline environments, the passivation of rebars occurs through anodic passivation coupled with the cathodic oxygen reduction reaction (ORR). The catalysis of ORR can expedite anode passivation. To investigate the corrosion inhibition of steel bars in alkaline environments, meso‐tetra(4‐carboxyphenyl)porphine (TCPP), known for its ORR catalytic properties, is selected. TCPP forms adsorption films on the surface of steel bars, facilitating the formation of passivation films. TCPP primarily adsorbs onto active sites on the surface of the passivation film, where lattice iron ions have leached. The adsorbed TCPP accelerates the formation of the passivation film through ORR catalysis, inhibiting the development of passivation film defects and enhancing the integrity and protection of the passivation film. The most significant effect is observed when the concentration of TCPP is 0.5 mmol/L. The physical adsorption of TCPP is primarily determined by the negative charge centers, namely the carboxyl group O and the pyrrole N. However, due to steric hindrance caused by the unrestricted rotation of the carboxyl benzene, the pyrrole N does not play a dominant role in chemical adsorption. Instead, the active site for chemical adsorption is the carboxyl group O. The adsorption process significantly reduces the diffusion coefficient of TCPP molecules, providing a robust and stable adsorption binding. Phthalocyanine molecules without carboxyl benzene groups adopt a planar structure, allowing them to form stable adsorption configurations on the iron surface through flat adsorption. This observation provides guidance for the design of novel metal phthalocyanine molecules. Specifically, the development of metal phthalocyanine molecules with modifying groups that are coplanar with the phthalocyanine ring and possess restricted rotation can achieve flat adsorption, improve coverage rate, and enhance adsorption configuration stability.

The Droplet Creeping-Sliding Dynamic Wetting Mechanism on Bionic Self-Cleaning Surfaces.

The dynamic wetting behavior of droplets has been of wide concern due to the hazards of accretion/icing of supercooled droplets on engineering components/systems served in low temperature freezing rain environment; thus, it is urgent to establish the relationship between droplet depinning/removing behaviors and surface characteristics. In this article, the actual rotation conditions of moving components such as wind turbine blades are simulated. The self-cleaning hydrophobic coating surface(S1) and bionic superhydrophobic coating surface(S2) show outstanding droplet removal performance compared to hydrophilic bare steel surface(S0), and the average speed of the droplet removal is increased by 400-500%. The "creeping-sliding" behavior of droplets on self-cleaning coatings is investigated by the change of droplet displacement(ΔD). The effect of the energy storage caused by the droplet creeping process provides initial kinetic energy for the droplet removal. Combined with the experimental data and theoretical model, the critical depinning resistance is calculated. The difference of the wetting interface free energy(ΔEx) during the dynamic wetting process of the droplets on the bionic superhydrophobic self-cleaning surface is researched. And the influence mechanism of the droplet embedded depth(x) on the creeping/sliding behavior in the nanotexture is clarified. Thus, the mechanical criterion of droplet depinning is proposed (the error is about 10%). The results can provide a theoretical basis for the design principle of antifreezing rain coatings on moving components.

Microcell and macrocell corrosion kinetics of steel bars in reinforced concrete slabs subjected to alternate wet and dry environments

Electrochemical kinetics of steel bar corrosion in concrete is of complex nature, especially when it is subjected to alternate wet and dry environments with changes in conditions of steel-concrete interface and rust properties. In this paper, a quantitative electrochemical mechanism was proposed based on thermodynamics and anodic polarisation kinetics to account for variations of microcell and macrocell current densities in reinforced concrete (RC) slabs subjected to periodic wetting and drying cycles. Effects of environmental conditions on corrosion process were incorporated into anodic Tafel slope through three quantifiable parameters, namely, corrosion potential, linear polarisation resistance and ferrous ion concentration at the steel bar surface. A numerical model was established based on the proposed mechanism to quantify microcell and macrocell current densities. An experimental programme of two RC slabs with multiple steel bars arranged at different layers was conducted to verify the numerical model. It shows that the model could reasonably predict variations of both microcell and macrocell corrosion under different wet and dry environments. When concrete was moistened, current density was substantially increased compared to that in dry concrete. Macrocell contribution from uncorroded steel bars at different layers was more significant than microcell corrosion on the corroded bar itself, especially in wet environments.

Evaluation of combined addition of nitrite and chloride on the corrosion behavior of steel bars in modified magnesium oxysulfate cement paste

Magnesium oxysulfate (MOS) cement, a new breed of eco-friendly and carbon-efficient material, boasts exceptional corrosion resistance, especially in harsh environments such as high salt and high humidity. Understanding how it affects the corrosion of steel bars is crucial for its widespread application in coastal concrete engineering. Nitrite-based inhibitors are known for their rust-preventing qualities in cementitious materials. However, more research is needed to determine if nitrite remains effective in MOS cement mixed with chloride salts. This study focuses on the combined effect of chloride and nitrite salts on the corrosion of steel bars in MOS cement. Methods like corrosion area rate, weight loss rate, natural potential, and electrochemical station are employed to study the corrosion behavior of steel in MOS cement. Microscopic techniques help unravel the influence mechanism of phase composition and microstructure on these materials. Furthermore, the study examines how chloride and nitrite contents affect the concentration of free nitrite and chloride ions in MOS cement paste. The analysis model is also established to compare simple linear adsorption, Langmuir adsorption, and Freundlich adsorption. The results indicate that chloride accelerates steel corrosion, while nitrite slows it down in the environment of mixed chloride and nitrite. In low-chloride environments, nitrite content has minimal impact on steel corrosion, but its effect becomes more pronounced in high-chloride settings. The MOS cement mixed with chloride and nitrite primarily consists of Mg(OH)2, MgCl2, MgCO3, MgO, and the 5Mg(OH)2·MgSO4·7 H2O (517 phase). The phase content of passive film on the surface of steel bar is composed primarily of Fe2O3, FeO, Fe, and FeOOH in descending order. As nitrite content increases, the absorption and concentration of free nitrite ions in the MOS cement paste gradually rise, exhibiting a linear trend. Based on the fitting calculations for three distinct adsorption relationships, notably, due to the limited adsorption capacity of MOS cement for nitrite, there's a considerable difference between the simple linear adsorption relationship and the two nonlinear adsorption models in high nitrite environments. However, in low nitrite concentrations, the difference among these three fitting adsorption relationships is little. This research can provide theoretical basis for enhancing the corrosion resistance and durability of coastal concrete engineering with high chloride exposure.

Improve corrosion resistance of steel bars in simulated concrete pore solution by the addition of EDTA intercalated CaAl-LDH

The main perspective of this paper is to prepare an eco-friendly corrosion inhibitor suitable for reinforced concrete. The properties of CaAl-LDHs loaded with ethylenediaminetetraacetic acid (EDTA) synthesized under different conditions were studied and the optimal condition was determined. Electrochemical tests showed that CaAl-EDTA-LDH had excellent anti-corrosion properties for steel bars in the simulated concrete pore (SCP) solution. Mechanistically, the dual protection mechanism of CaAl-EDTA-LDH on steel bars was mainly due to the fact that the organic corrosion inhibitor adsorbed on the surface of steel bars to form a protective film while consolidating chlorides.

Microscopic mechanisms and chloride resistance performance of silane coupling agent self-assembly on reinforced concrete utilizing X-ray CT technology: A comprehensive investigation

To enhance corrosion resistance in reinforced concrete exposed to chloride environments, a γ-aminopropyltriethoxysilane (KH550) solution was used to treat the steel bar surface. This study investigated the corrosion resistance and microscopic mechanism of self-assembled silane film-modified steel bars. Surface morphology, elemental composition, and functional group changes were analyzed using SEM, EDS, and FTIR before and after solution treatment to determine the optimal treatment concentration. X-ray computed tomography (X-ray CT) was employed to analyze rust evolution and fracture characteristics in steel bars treated with silane coupling agent self-assembly technology. Results revealed that the self-assembly of molecules significantly enhanced corrosion resistance when using a water to ethanol to KH550 solution volume ratio of 50:3:10. The corrosion resistance mechanism of silane self-assembled steel bars against chloride salt corrosion was verified through X-ray CT technology, quantifying the volume expansion rate of rust products.

Bioinspired coating based on fluid: Electrochemical fabrication and corrosion protection for steel

BackgroundSteel corrosion poses a significant challenge, and coating plays a pivotal role in preventing it. In this study, instead of using solid materials, we explored air-based coating inspired by lotus leaves and liquid-based coating inspired by pitcher plants, collectively known as fluid infused coatings, to protect steel from corrosion. MethodInitially, Zn metal is prepared through electrochemical deposition, followed by anodization of the zinc metal to achieve a radially structured surface of zinc oxide. Surface modification is then conducted to create a superhydrophobic surface (SHS) by storing gas. The liquid coating is obtained by infusing the liquid oil into the superhydrophobic matrix by replacing air phase. Significant findingsWhen subjected to a salt spray, the resulting salt particle takes the form of doughnut rather than a spreading pancake shape on bare steel plate. From an adhesion standpoint, the contact area between the doughnut-shaped salt particle and SHS is significantly smaller compared to the pancake-shaped salt particle on bare steel surface. As a result, the salt particle tends to detach from SHS. Corrosion protection investigations are carried out on these fluid-based coatings using electrochemical techniques and other methodologies, revealing that the liquid-based coating system exhibits significantly larger efficacy compared to the gas-based fluid coating.

Corrosion inhibition mechanism of vitamins on steel bars in chloride environments: Experimental analysis and quantum chemical calculation

The inhibition potency of thiamine (VB1), nicotinic acid (VB3), pyridoxine (VB6) and ascorbic acid (VC) against the reinforcement corrosion and their adsorption behavior on the surface of steel bars in chloride environments are studied using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) tests. Based on the density functional theory (DFT), quantum chemical calculation is also performed to further reveal the corrosion inhibition mechanism of vitamins at the electronic level. The results indicate that these four kinds of vitamins are proven to be potentially applied as corrosion inhibitors to effectively reduce the risk of chloride-induced reinforcement corrosion in a simulated concrete pore solution with 0.05 M NaCl, and VB6 shows the best corrosion inhibition effect since the bonding stability between its highest occupied molecular orbital (HOMO) and the 3d-orbital of iron is the strongest among these vitamins. Under the experimental conditions of this study, there is a specific concentration value for each vitamin to achieve the optimum corrosion inhibition efficiency (IE%). At this time, VB1 and VB3 act as anodic corrosion inhibitors, while VB6 and VC act as mixed-type corrosion inhibitors. With the increase of vitamin concentration, IE% shows a fluctuating value, which is ascribed to the further aggravated imbalance between the cathode and the anode when the cathodic reaction is inhibited due to the adsorption of polar groups on the steel surface.

Inhibition resistance and mechanism of migrating corrosion inhibitor on reinforced concrete under coupled carbonation and chloride attack

Corrosion of steel bars in the marine environment is an important reason to reduce the service life of reinforced concrete structures. In this study, an amino alcohol migrating corrosion inhibitor (MCI) was coated on the concrete surface, which was then subjected to a simulated marine atmospheric environment by carbonation and salt spraying. The carbonation depth, chloride concentration of concrete, electrochemical performance of steel bars and mass loss rate of steel bar were determined to evaluate the corrosion inhibition performance of MCI. NELD-BS610 hardened concrete bubble spacing coefficient analyzer and scanning electron microscopy (SEM) were applied to analyze the pore structure parameters in concrete and the corrosion behavior of steel bar, respectively. The test results showed that MCI could alleviate the deterioration of concrete induced by accelerated carbonation and chloride attack, and delay the carbonation effect. After 7 days of accelerated carbonation and 35 days of chloride attack, the carbonation depth and chloride concentration of concrete coated with MCI were 16.07% and 16.93% lower than those of concrete uncoated with MCI, respectively. MCI could migrate to the steel bar surface of steel bar to form a protective film, significantly improving the electrochemical performance of the steel bar, and the inhibition efficiency of MCI was about 66.07 ∼ 97.91%. Besides, MCI could also reduce the mass loss rate of steel bars and porosity of concrete induced by carbonation and chloride attack. For the specimens coated with MCI, the mass loss rates of steel bar decreased by 20.31 ∼ 39.78%, and pores with sizes of 1.0 ∼ 0.2 μm in concrete reduced by 59.10 ∼ 76.38%. The results of this research are purposeful for alleviating the corrosion damage problems of reinforced concrete in marine areas.

Low-Frequency ultrasonic tomography of Corrosion-induced damage patterns on naturally corroded solid reinforcing bar rock bolts

A combined non-destructive guided ultrasonic wave measuring approach and low-frequency ultrasonic tomography technique on cylindrical surfaces is developed to investigate corrosion-induced damage patterns in naturally corroded 60-year-old solid rebars. The main goal of low-frequency tomographic imaging simulations is for differential detection of general and localized pitting corrosions on cylindrical surfaces of solid steel bars. The modified damage probabilistic reconstruction algorithm for cylindrical surfaces is also adopted to simulate naturally general and localized pitting corrosion patterns. To increase the ray density or resolution of images, a regular array of accelerometer sensors with high-density spatial distributions around the cylindrical surface of steel bars is installed for a fixed piezocomposite actuator. As such, an efficient sensor deployment method can be applied with the trilateration technique to achieve effective coverage and connectivity properties between accelerometer sensors. Stochastic signal processing which is elicited from the Hilbert-Huang Transform (HHT) signal method is also employed to analysis low-frequency tomography time domain algorithms. Finally, optical surface profilometry approaches, and static state tensile testings, together with scanning electron microscopy (SEM) are adopted to confirm the effectiveness of non-destructive and tomography imaging techniques. The results show that the guided wave signals with excitation frequency of less than 10 kHz can be precisely employed to identify the general and localized pitting corrosion distributions on the cylindrical surfaces of steel bars and qualitatively reconstruct them using low-frequency ultrasonic tomography simulations. This research study also demonstrates that the low-frequency ultrasonic tomography simulations can be effectively applied in corrosion pattern uncertainty modelling.

Tribo-catalysis triggered the in-situ formation of amphiphilic molecules to reduce friction and wear

A coating composed of Au/Ag/Cu was deposited onto steel surfaces to catalyze the tribochemical reaction of polyalphaolefin (PAO), resulting in the formation of amphiphilic molecules. The coated surface showed a reduction in friction coefficient and wear track width by 24.9∼43.0% and 61.4∼68.9%, respectively, compared to the bare steel surface. The in situ formed amphiphilic molecules were chemically bonded on tribopair surface after deprotonation, and then formed a tribofilm. This tribofilm exhibited low interfacial adhesion at nano scale, contributing to low friction and wear. Density functional theory simulations reveals that the dissociation energy of C-H bond on Au surface was much lower than that on iron surface, favoring the catalytic oxidation reaction of PAO into amphiphilic molecules.

Effect of Processing Technology on Mechanical Properties of HRB500 High-Strength Steel Bar Threading

The processing quality of steel bar thread has a large influence on its performance. Using the traditional thread processing technology, it is difficult to meet the requirements of steel bar thread processing with large diameter and high strength. A technical process for HRB500 high-strength steel bar thread processing, including face milling, rib stripping, chamfering, necking formation, and thread rolling, was proposed. The influences of cutting parameters on the cutting force of steel bar surface in face milling were analyzed by the finite element method. For the necking formation process, the effect of springback amount on necking formation was studied. The main parameters in rolling formation were analyzed and calculated, including extrusion pressure, rolling speed, and rolling feed. Experiments for uniaxial tensile of the processed high-strength steel bar threads were carried out. The results showed that cutting depth has the largest influence on the cutting force; the second is feed rate. The effect of the spindle speed was lowest during the face milling. After the necking formation process, the values of the maximum springback amount along the X, Y, and Z directions were 0.05 mm, 0.06 mm, and 0.98 mm, respectively. The finished thread met the precision and quality requirements of a grade I joint. This study provides a high-quality processing technology for large-diameter and high-strength steel bar threads.

Observation of Transition Area Origin Cracks on Fracture Surfaces of Carburized JIS SCM415 Bars

Under high cycle and very high cycle fatigue, high strength steels break as a result of internal fracture from inclusions. In order to understand this fracture, “Fisheye” crack has been investigated. In our previous work we found that cracks grew from the boundary between the hard surface and soft core of case-hardened S45C, SUJ2 and SCM415 steel bars under rotating bending fatigue. These cracks were called “Transition area origin (TRO)” cracks. In this study, we closely observed the fracture surface of TRO crack areas in carburized JIS SCM415 specimens (under 734, 776 and 865 MPa). We found three features of the TRO cracks: outside of the TRO cracks had asperities; the shapes of TRO cracks were almost circular, and were different from those in S45C and SUJ2 steels; and the HAZ-TRO area which was located at hardened layer had some ridges, and the Core-TRO area at unheat-treated layer was smooth and flat.

Comparative Studies on Steel Corrosion Resistance of Different Inhibitors in Chloride Environment: The Effects of Multi-Functional Protective Film

A corrosion inhibitor was widely used to improve corrosion resistance of steel bar in reinforcement concrete structure. A kind of multi-component corrosion inhibitor, which is composed of organic and inorganic substances, was developed in this research. This corrosion inhibitor was comparatively studied with various other inhibitors by using open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV) methods. The results show that the OCP values and charge transfer resistance (calculated by EIS curves) of the multi-component corrosion inhibitor remain, respectively, as high as −0.45 V and 932.19 kΩ·cm−2 after 60 days immersion, which are significantly better than other groups. Wide passivation interval and various peaks in cyclic voltammograms (CV) were applied to analyze the mechanism of adsorption (organic substance) and oxidation–reduction reactions (inorganic substance). The functional groups -OH in triethanolamine (TEA) and tri-isopropanolamine (TIPA) bond to the steel bar surface quickly, behaving as an adsorbent of organic substance in early age. An additional protective precipitate related to the reactions of Fe3+ was formed by inorganic substances (Fe2(MoO4)3 and FePO4), which is consistent with the EIS results and equivalent electrochemical circuits. As an eco-friendly substitute, multi-component corrosion inhibitors possess similar or even better protecting effects on steel bars in comparison to calcium nitrite. In addition, the concept of a “multi-functional protective film” was proposed, providing a new insight to achieve modified anti-corrosion capacity of inhibitors.

Graphene oxide as an anti-corrosion coating on carbon steel: effect of surface structure and wettability of steel

ABSTRACT According to the literature data graphene oxide cannot be easily used as an anti-corrosion barrier on metals and alloys, especially on carbon steel. This article shows that the oxidised form of graphene can improve the electrochemical corrosion parameters of carbon steel, if necessary modifications on the surface structure and wettability of steel are made prior to the coating step. In this study, the effects of surface roughness and hydrophilicity of carbon steel on the anti-corrosion performance of the electrophoretically deposited graphene oxide were investigated by potentiodynamic polarization and electrochemical impedance spectroscopy. The results showed that increasing the roughness and hydrophilicity of the bare steel surface promotes the mechanical interlocking/adhesion between the graphene oxide and steel and this improves the protective performance of the deposited graphene oxide barrier on steel.

Modeling electrochemical chloride extraction process in cement-based materials considering coupled multi-ion transports and thermodynamic equilibriums

This paper proposes an electrochemical chloride extraction (ECE) model for cement-based materials that considers coupled multi-ion transport, adsorption and dissolution. Then ECE tests were designed and conducted to validate the proposed ECE model. Based on the proposed ECE model, parametric studies were conducted. Parametric studies show that the chloride binding capacity of cement pastes depends heavily on the contents of aluminate ferrite monosulfate (AFm) and alumina ferrite tri-sulfate (AFt). Moreover, the content compositions of free, absorbed and chemically-bound chloride ions vary with the types of chloride salts, i.e., the cations in the chloride salts. Moreover, temperatures within the range between 5 °C and 40 °C pose negligible influences on the ECE process. Current densities and durations are the most influential factors affecting the ECE process, which are thus the main parameters to be determined for the design of ECE. In addition, the chloride ion content distributions are bell curves during the ECE process and peaks exist within the concrete cover. Therefore, it is recommended to adopt three chloride ion contents as controlling indexes for the ECE process, i.e., 1) the chloride ion content at the surface of steel bars, 2) the average chloride ion content within the concrete cover and 3) the peak chloride ion content within the concrete cover.