Rebar Corrosion Research Articles

Effect of Ce on structural evolution and corrosion resistance of HRB500E rebar corrosion layer

HRB500E rebar is a low-alloy high-strength steel with excellent mechanical properties and good plasticity but suffers from deficient corrosion resistance. This can be solved by adding trace elements, including rare earth elements. Herein, the corrosion-resistant behavior of rebar was evaluated by weightlessness testing and electrochemical measurements, and the effects of Ce on the structural evolution of the corrosion product layer were investigated by scanning electron microscopy (SEM), Electron Probe X-ray Micro-Analyzer (EPMA), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The results showed that adding Ce to the rebar improved the densification of the reinforcing surface corrosion products, as well as reduced the corrosion rate of the experimental rebar. Compared to C0 sample without Ce, the rebar sample containing 0.044 wt.% Ce displayed increased Ecorr by 0.051 V, decreased Icorr by 15.573 mA cm−2, enhanced Rc of the corrosion product layer by 112.71 Ω cm2, incremented α-FeOOH content in the corrosion product layer, and boosted ratio of α/γ* in the corrosion product layer by 10.11%. Furthermore, the oxide (CeO2) formed by Ce in the corrosion layer of the rebar bar surface existed in the rust layer, resulting in a stable corrosion product layer with improved blocking ability of the corrosive medium. Overall, the addition of Ce at certain ratios looks promising to produce HRB500E rebar with excellent corrosion resistance and extended service life under harsh conditions.

Gaussian process regression driven rapid life-cycle based seismic fragility and risk assessment of laminated rubber bearings supported highway bridges subjected to multiple uncertainty sources

Structural attributes, corrosion of steel rebars in reinforced concrete (RC) columns, thermal oxidative aging of inherent rubber in laminated rubber bearings (LRBs), replacement of LRBs, and the time-dependent seismic hazard level at the bridge site are well recognized as the main factors that affect the accurate assessment of the seismic performance of RC bridges implemented with LRBs. However, the probabilistic seismic demand model (PSDM) and probabilistic structural capacity model (PSCM) of deteriorated bridge components may not exhibit homoscedastic log-linearity. And the expansion of seismic fragility surfaces and seismic risk curves in the temporal dimension requires a considerable computational cost on the nonlinear analysis, which regretfully has not been well addressed in current studies. To fill in this gap, this study proposes a life-cycle based seismic fragility and risk assessment framework for LRBs supported RC bridges considering deterioration mechanisms of bridge components during their life cycles demonstrated by a three-span LRBs supported highway bridge considering multiple uncertainties such as the replacement interval for LRBs. In this framework, Gaussian process regression (GPR) is employed to effectively construct the PSDM and PSCM of deteriorated bridge components, and then the time-dependent seismic fragility surfaces of bridge components and bridge system are established. Life-cycle based seismic risk analysis is conducted to quantify the coupled time-dependent effects of deterioration and site seismic hazard on a newly built bridge during its design service life and a deteriorated bridge within its remaining service life, respectively. Results indicate that GPR can successfully capture the nonlinearity and heteroscedasticity characteristics of PSDM and PSCM, leading to a significant reduced number of nonlinear analysis cases to generate the time-dependent seismic fragility surfaces and seismic risk curves. Consequently, the proposed framework using GPR can significantly improve the accuracy and efficiency of life-cycle based seismic performance assessment when uncertainties of structural attributes, deterioration progress and seismic hazard are taken into consideration.

Interactive effects of moisture, chloride, and carbonation on rebar corrosion in mortar

This study investigates the synergistic effects of chloride ions, carbonation, and relative humidity on rebar corrosion in mortar, elucidating the complex interactions at the rebar-mortar interface. Findings reveal that chloride ions and carbonation significantly alter the volumetric water content and resistivity of mortar, leading to non-binary corrosion behaviour through area effect, ohmic control, and anode-to-cathode ratio. In chloride-free, non-carbonated mortar, the area effect dominates, whereas the presence of chloride introduces ohmic control and a saturation-dependent anode-to-cathode ratio. In carbonated mortar, a distinctive ohmic control mechanism emerges, governed by local ionic conductivity. This study highlights the critical need to consider these combined effects for accurate prediction and mitigation of rebar corrosion in concrete structures. By advancing the understanding of these mechanisms, the research provides valuable insights for improving the durability of reinforced concrete structures exposed to harsh environmental conditions.

Corrosion inhibition of steel rebar in chloride-contaminated concrete pore solution: Ecofriendly glutamic acid inhibitor and its synergy with galvanized coating

In this study, we explore the effectiveness of glutamic acid as corrosion inhibitor for protecting steel rebars within a concrete pore solution contaminated with chloride (CCCPS) along with its synergy with galvanized coating are investigated. The study is defined in two phases: (a) examining the inhibition efficiency (%IE) of glutamic acid at various concentrations of 0.25, 0.50, 0.75, and 1 g/L using a combination of experimental and theoretical methods, and (b) evaluating its synergistic effect with Zn present in the galvanized coating. In the first phase, various electrochemical tests and theoretical investigations are employed. The electrochemical examinations consistently demonstrated that at a concentration of 1 g/L, the maximum %IE reaches ∼ 80 %. Langmuir adsorption isotherm fitting effectively describes the relationship between inhibitor concentration and its coverage percentage. Thermodynamic data indicate the adsorption of these inhibitors on the steel surface involves both physical and chemical adsorptions with a ΔG°ads (standard free energy of adsorption) of around –23.5 kJ/mol. Moreover, the activation energy for corrosion of steel rebar increases from 55.8 kJ/mol for the blank CCCPS to 78.3 kJ/mol for the inhibited CCCPS. Molecular dynamics simulations validate the binding of glutamic acid molecules to the surface of the steel, primarily through nitrogen atoms orientation towards d-orbitals of steel substrate. In the second phase, the carbon steel rebar underwent hot-dip galvanization, resulting in a galvanized coating with a thickness of approximately 36 µm. The synergistic effect of glutamic acid at its optimum concentration (0.75 g/L) was investigated with comparison of the corrosion behavior of three samples: bare steel, galvanized steel, and scratched galvanized steel in simulated CCCPS with and without the inhibitor. Results indicate that the presence of the inhibitor significantly enhances the %IE, up to 99 %, for scratched galvanized steel. FESEM/EDS analysis further reveals a substantially lower volume of corrosion products in the scratched area of the latter sample compared to its counterpart in the inhibitor-free solution. Furthermore, as indicated by the findings from X-ray photoelectron spectroscopy (XPS), the interactions between the N and Fe atoms, acting as donors and acceptors, respectively, hold significant importance in the chemisorption process.

Corrosion effects on bond strength in reinforced concrete with fly ash

Reinforcing steel bars provides additional strength and ductility to concrete by forming a strong bond with the concrete matrix. Corrosion of steel bars can significantly reduce the bonding effect between the steel bar and concrete, which can compromise the structural integrity and durability of reinforced concrete structures. An experimental investigation was performed to examine the influence of fly ash (FA) and corrosion on concrete–steel bond behavior. The accelerated corrosion method was employed to obtain the desired level of corrosion. The FA content, corrosion percentage, and presence of stirrups were considered significant factors influencing bond behavior. The bond–slip curves and bond toughness were used to discuss bond behaviors. The findings indicated that mild corrosion (below 2.5%) can enhance concrete–steel bond performance, and the addition of 20% FA leads to higher ultimate bond strength (τu ), significantly mitigating the decrease in bond strength caused by severe rebar corrosion. Also, this study analyzed the influence of stirrups on the bond strength of FA concrete and had a nearly insignificant effect compared to regular concrete. The results and discussions of the present study carry significant importance in the establishment of a bond–slip constitutive model under multifactor coupling conditions. Furthermore, it offers valuable insights into the design of engineering structures.

Synergistic effect of benzo triazole with polyethoxylated sorbitan monooleate in inhibiting corrosion of rebars and chloride diffusion through mortars

It is found that mixture of 1,2,3 benzo triazole (BTAH) with polyethoxylated sorbitan monooleate, a non-ionic surface-active agent (NIS) effectively improves the properties of the cast concrete as well as significantly reduces the chloride induced corrosion of steel reinforced bars, when added in freshly prepared paste of mortar mixture. The addition of this mixture in the cast mortars is noted to reduce the water absorption in comparison to the control mortars cast using identical materials and under similar cast conditions. Electrochemical impedance spectroscopy and polarization studies of the rebars embedded in mortars and exposed in cement slurry have been performed to study the role of synergistic mixture on kinetics and mechanism of corrosion of rebars. The characterisation of corrosion products formed on the surface of rebars was carried out by X-ray diffraction, Scanning electron microscopy and EDX analysis. It is proposed that the synergistic boosting in protection is caused due to the shielding of NIS around anionic BTA−, thus minimizing their electrostatic repulsion. This facilitates the migration of additional ionic BTA towards the double layer which increases their concentration at the corroding interface leading to reduced susceptibility to corrosion.

Experimental and analytical investigations on flexural performance of corroded RC beams using RBSM-based corrosion model

Residual strength and structural performance of reinforced concrete (RC) structures subjected to rebar corrosion need to be precisely evaluated for an efficient rehabilitation process. However, the performance of deteriorated structures cannot be specified by using design methods since the damaged conditions are different in each type of structures due to corrosion degree, corrosion position, environmental condition. This study first presents an experimental investigation on the flexural performance of RC beam subjected to rebar corrosion. To complement the test data, an analytical corrosion model developed by the authors, which is based on Rigid Body Spring Method (RBSM), was employed. The results obtained from both analytical model and experiment confirmed that the corroded beam appeared to obtain a significantly lower bending stiffness and lower flexural capacity than those of the sound beam. The developed corrosion model can be able to capture the load-displacement curve of experimental results with good agreement.

Influence of Corrosion on Lifespan of Reinforced Concrete Structures: A Comprehensive Review

Carbonation-induced corrosion is a major concern for reinforced cement concrete (RCC) structures, impacting their long-term durability and structural integrity. This review synthesizes the findings on the deterioration mechanisms in concrete structures, focusing on carbonation, chloride-induced corrosion, and time-dependent deterioration. The analysis includes discussions on predictive likelihood methods for estimating bridge reliability, the impact of environmental factors on carbonation, and standardized testing methods for assessing concrete durability. The review highlights the importance of understanding material characteristics and environmental conditions in designing durable concrete structures, emphasizing the processes of carbonation, its impact on rebar corrosion, and strategies for mitigation. Sheltered concrete carbonation resistance in metropolitan tropical climates is 10-20% lower than open exposure. SCM concretes exhibit equivalent or greater long-term carbonation resistance to OPC concretes, as evidenced by the increase in carbonation depth ( Δ xd) at ages greater than 5 years. The paper concludes with recommendations for integrating advanced modeling techniques and empirical studies to develop robust maintenance strategies and improve concrete mix designs for enhanced durability.

Concentrically loaded concrete columns reinforced with steel-FRP composite bars (SFCB) and carbon fibre-reinforced polymer mesh fabric (CFRP-MF) stirrups

Corrosion of rebar is a major cause of performance degradation in coastal structures, and thereby, significantly affects their durability and safety. To address this issue, a new corrosion-resistant reinforced composite structural concrete column were formed by using basalt fibre-reinforced composite bar (SFCB) as the longitudinal reinforcement and carbon fibre-reinforced polymer mesh (CFRP-MF) as an alternative to stirrup. Eight columns were subjected to an axial compression test to determine their capacity. The effects of different combinations of embedded reinforcement, concrete strength, and CFRP-MF stirrup ratio on the cracking performance, ductility, and axial load carrying capacity were investigated. A nonlinear finite element modelling was used to predict axial compressive response of concrete column reinforced with SFCB and CFRP-MF stirrups, and parametric analyses were conducted. The experimental results indicated that all tested columns reinforced with CFRP-MF stirrups were damaged in the central region of the specimens with extensive peeling of the protective layer. To ensure optimal structural safety, it is recommended that SFCB adopt the equal stiffness alternative method to replace longitudinal reinforcement. The substitution increases load-carrying capacity and ductility of the specimen by 5.4 % and 7.8 %, respectively. The study proposes an improved design model for predicting the Nu of columns reinforced with SFCB and CFRP-MF stirrups, which enhances prediction accuracy and precision when compared with existing codes. The findings contribute innovative insights and practical recommendations for advancing the utilization of seawater sea sand concrete and its application in coastal engineering projects.

Experimental and numerical assessment of GFRP and synthetic fiber reinforced waste aggregate concrete members

Improper disposal of plastic waste (P-waste) poses significant pollution and health risks to the environment. Additionally, steel rebar corrosion in concrete structures reduces their strength and serviceability. To address these issues, this study explores using glass fiber-reinforced polymer (GFRP) rebars and replacing natural coarse aggregates with P-waste aggregates for sustainable and eco-friendly construction. This work investigates the axial performance of polypropylene structural fiber-reinforced P-waste aggregate concrete (SFPC) compressive components having GFRP-reinforcement (GSFPC) under various loading conditions. For comparison, steel-reinforced SFPC compressive components (SSFPC) were also fabricated. Eighteen circular components with 1200 mm height and 300 mm diameter were tested and compared under different loading conditions. SSFPC components exhibited up to 21.9 % higher axial strength but up to 27.4 % lower ductility compared to GSFPC components. Eccentric loading similarly reduced axial strength in both GSFPC and SSFPC components. A 3-D finite element analysis (FEA) of GSFPC components was proposed using a modified damaged plastic model for SFPC which showed deviations of 2.3 % in axial strength and 7.7 % in equivalent axial shortening, demonstrating a good accuracy of the FEA model.

Review on Rebar Corrosion in Alkali-Activated Concrete Subjected to Chloride-Rich Environment

Review on Rebar Corrosion in Alkali-Activated Concrete Subjected to Chloride-Rich Environment

Anti-corrosive superhydrophobic coatings for reinforcement protection: recycling of concrete garbage

PurposeThe purpose of this paper was to prepare a ternary hierarchical rough particle to accelerate the anti-corrosive design for coastal concrete infrastructures.Design/methodology/approachA kind of micro-nano hydrophobic ternary microparticles was fabricated from SiO2/halloysite nanotubes (HNTs) and recycled concrete powders (RCPs), which was then mixed with sodium silicate and silane to form an inorganic slurry. The slurry was further sprayed on the concrete surface to construct a superhydrophobic coating (SHC). Transmission electron microscopy and energy-dispersive X-ray spectroscopy mappings demonstrate that the nano-sized SiO2 has been grafted on the sub-micron HNTs and then further adhered to the surface of micro-sized RCP, forming a kind of superhydrophobic particles (SiO2/HNTs@RCP) featured of abundant micro-nano hierarchical structures.FindingsThe SHC surface presents excellent superhydrophobicity with the water contact angle >156°. Electrochemical tests indicate that the corrosion rate of mild steel rebar in coated concrete reduces three-order magnitudes relative to the uncoated one in 3.5% NaCl solution. Water uptake and chloride ion (Cl-) diffusion tests show that the SHC exhibits high H2O and Cl- ions barrier properties thanks to the pore-sealing and water-repellence properties of SiO2/HNTs@RCP particles. Furthermore, the SHC possesses considerable mechanical durability and outstanding self-cleaning ability.Originality/valueSHC inhibits water uptake, Cl- diffusion and rebar corrosion of concrete, which will promote the sustainable application of concrete waste in anti-corrosive concrete projects.

Assessing the effect of sodium nitrite as corrosion inhibitor against the corrosion of steel rebar in alkali-activated concrete

The aim of this study is to investigate the effectiveness of corrosion inhibitor against chloride-induced corrosion of steel rebar in fly-ash (FA) and GGBS (ground granulated blast furnace slag) and Nanofine-based alkali-activated concrete. The Alkali-Activated Concrete (AAC) was prepared from FA, ground granulated blast furnace slag (GGBS), and Nanofine with Sodium hydroxide (NaOH) and Sodium Silicate (Na2SiO3) solutions. The concentration of NaOH varies to 10 M, 12 M, and 14 M, and all the specimens were subjected to accelerated corrosion, to perform the non-destructive test after the corrosion of the steel rebars. Fourier Transform Infrared (FTIR), scanning electron microscope (SEM), Energy dispersive X-ray spectroscopy (EDS), and Electron Backscatter Diffraction (EBSD) were used to examine the microstructure of AAC in the presence of Nano-Fine GGBS (NF), Sodium Chloride (NaCl), and NaNO2 and to compare the strength and corrosion properties with AAC and OPC. The ratio of sodium silicate to sodium hydroxide was taken as 2.5 and the solution-to-binder ratio was taken as 0.5. The compressive strength and ultrasonic pulse velocity (UPV) test of the Nano-fine based alkali-activated concrete increases as compared to the control concrete. The increase in the dosages of corrosion inhibitor and nano-fine increases the compressive strength of the control concrete and alkali-activated concrete. The half-cell potential of the control concrete and nano fine admixed with alkali-activated concrete mixes with different molarities is uncertain. The increases in the dosages of corrosion inhibitors reduce the occurrence of corrosion in the steel reinforcement rebars.

Mechanism of rebar depassivation in concrete containing sulphate: A vicious cycle between sulphate adsorption and surface vacancy formation

Sulphate-induced corrosion of rebars has been reported to plague the lifespan of concrete structures. However, the associated mechanism underlying this issue is still unclear and therefore deserves further investigation. To fill in this gap, three electrochemical experiments including OCP, EIS and LPR were conducted in this study, alongside XPS and SEM characterizations. Moreover, a Density Functional Theory (DFT) was adopted to simulate the depassivation behaviour of rebar under the sulphate condition. Taking together, the underlying mechanism was disclosed. The results reveal that the presence of sulphate ions appeared to reduce the thickness of the rebar passive film and the Fe3+/Fe2+ ratio in the outer layer. In addition, the threshold value of [SO42−]/[OH−] to cause the depassivation of rebar was experimentally found about 1.26–1.51 in the saturated Ca(OH)2 solution. Further, the pristine and vacancy-contained α-Fe2O3 (001) surfaces were chosen respectively, to simulate the passive film surface surrounding rebars via DFT. It was found that the SO42− adsorption boosted the formation of surface vacancy, and compared to the pristine surface, the increase in SO42− coverage also promoted the ensuing formation of Fe vacancy on the O vacancy-contained surface. Then, the Fe-O pair vacancy was so formed, and in turn, boosted the following adsorption of SO42− on the passive film of rebars. Combining the experimental results and DFT simulation, the vicious cycle is believed to exist during the sulphate-induced depassivation of rebar, specifically composed of (i) the adsorption of SO42−, (ii) the vacancy formation and increase, and (iii) the progressively enhanced adsorption of SO42−.

Predicting corrosion behaviour of steel reinforcement in eco-friendly coral aggregate concrete based on hybrid machine learning methods

ABSTRACT This study proposes a machine learning-assisted method for assessing steel reinforcement corrosion, utilising data on chloride ion concentration (CIC) and chloride ion concentration threshold (CCT) from eco-friendly coral aggregate concrete (EFCAC). A total of 2185 data points were collected to establish the EFCAC-CIC database. A multi-objective slime mould optimised support vector regression (MOSMA-SVR) model for EFCAC-CIC was developed. The significance of each feature to EFCAC-CIC was analysed. Subsequently, a graphical user interface (GUI) was developed based on the MOSMA-SVR model. Finally, the GUI and EFCAC-CCT were used to assess the corrosion behaviour of reinforcement. Results indicate that the MOSMA-SVR model provides predictions that are closer to the actual values, with smaller mean errors and standard deviations. The performance indicators, including coefficient of determination, mean absolute error, mean absolute percentage error, mean square error, root mean square error, and a20-index, of the MOSMA-SVR model are 0.987, 0.0124, 0.0332, 2.91e − 4, 0.0171 and 0.9991, respectively, and they are superior to those of the other tested models. The water type and the water–binder ratio are identified as the two most critical factors. Furthermore, by integrating the GUI and feature importance analysis results, chloride salt-resistant EFCAC can be designed. When this is combined with the GUI and EFCAC-CCT, the corrosion of rebar in EFCAC can be assessed in real time.

Permittivity analysis of weathered concrete in a bridge based on open-ended probe and impedance measurements

Pathologies like corrosion of rebars or alkali aggregate reactions in a reinforced concrete (RC) bridge are usually accompanied by the existence of aqueous pore solutions with a high concentration of ions. The distribution of aqueous solutions in the concrete is inhomogeneous and depends on the RC’s location in the bridge and complex climate factors. Frequency-dependent complex permittivity is sensitive to aqueous pore solutions because the high conductivity caused by charge carriers can result in a large imaginary part of the permittivity, much higher than that caused by water. In this study, we used a non-destructive open-ended probe to measure the complex permittivity of the RC in a bridge’s pillar with different levels of pathologies. By measuring the impedance of core samples with various controlled water volumetric fractions in the laboratory, the water effect on the evolution of the loss tangent (the ratio between the imaginary part of the permittivity and the real part) can be calibrated. Comparing the loss tangent in the bridge with that of the core samples treated by water, we can map the areas with a high density of aqueous pore solution and cracks, and estimate the unhealthy area with partial damage in the pillar by an effective and non-destructive diagnosis.

Application of Digitised Frequency Modulated Thermal Wave Imaging for Testing and Evaluation of Rebar Corrosion in Concrete Structures: A Numerical Study

Application of Digitised Frequency Modulated Thermal Wave Imaging for Testing and Evaluation of Rebar Corrosion in Concrete Structures: A Numerical Study

Study Of The Impact Of Several Coatings In Minimizing The Rebar Corrosion In Concrete

This paper represents experimental study to examine the influence of several coatings to decrease the rebar corrosion. The experiments were carried out for three types of coatings. Those have been painted on the steel and select the best type of coatings in decreasing the steel corrosion rate. Testing program included experiments to select the best one within three types of coatings (Isonem MS Polymers, Sika Zink Rich-1, Isonem PU Floor) are used and available in market. The result of corrosion rate for rebar in uncoated samples in level five (after 70 days) was loss of more than 50% from its weight. While, the result of corrosion rate for rebar in samples with coating type (C) ”Isonem PU Floor” was loss of less than 2% from its weight which is the most effective type and the best coating.

Effects of electroless nickel -coating on tribological and corrosion behaviour of TMT steel rebar with multi-walled carbon-nanotube and titanium dioxide nanoparticles

This study incorporated Multi-walled carbon nanotube particles (MWCNTs) and Titanium Dioxide Nanoparticles (TiO2) into a metal matrix composite in Ni–P coated substrate using an Electroless technique. This study significantly improves the tribological properties, enhances corrosion resistance, increases durability and extends the service life of coated rebar. Coated rebar helps make infrastructure more sustainable by extending the life of buildings and lowering their material consumption, trash output, and ecological footprint. The tribological behaviour of steel rebar has been studied by using a variety of characterization techniques, like X-ray diffraction, Atomic Force Microscopy, Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (EDX) including the corrosion test and the hardness test. The topographical roughness of the bare specimen, Ni–P coated specimen, CNT coated specimen and TiO2 coated specimen are 67.4 nm, 112 nm, 201 nm, and 162 nm respectively. The microhardness of the bare substrate, Ni–P coated, CNT doped coated, and TiO2 dopped coated specimens was done using Vicker's Hardness tester and the mean values were 455 HV, 580 HV, 810 HV, and 680 HV respectively. Resistance to corrosion of TMT steel rebar of Fe500 was examined using the polarisation method and Electrochemical-Impedance-Spectroscope (EIS) method. These techniques were examined in 3.5 wt% aqueous medium of NaCl and analysed the Ecorr (corrosion potential) and Icorr (Corrosion current density) of the bare substrate, Ni–P coated, Ni–P/CNT and Ni–P/TiO2 substrate. The corrosion inhabitation efficiency of the Ni–P-CNT doped was 22.5% more than the Bare substrate, and the TiO2 doped coated specimen was 10.63% more than the bare substrate. Resistance to corrosion of the CNT-coated substrate is better than Ni–P/TiO2 and Ni–P-coated specimens.

Effect of loading level on the corrosion resistance of a novel self-healing cementitious composite

A novel self-healing cementitious composite SMA-ECC is utilized to enhance corrosion resistance and maintain mechanical properties in chloride environment. The purpose of this study is to investigate the impact of the loading level on embedded steel rebar corrosion and the self-healing performance of SMA-ECC. The study examined the damage conditions, mechanical properties, and rebar corrosion resistance following a loading test. Chloride ingress depth and electrochemical tests were adopted to evaluate the corrosion resistance of the specimens. The findings reveal that SMA-ECC exhibits remarkable self-healing abilities in terms of damage recovery and restoration of mechanical properties. Cracks smaller than 50 μm can achieve a 100 % closure rate in SMA-ECC. It was observed that specimens with less damage (50 %, 70 % damage conditions) displayed improved chloride resistance (SMA-ECC in 50 % damage condition has equivalent corrosion resistance in terms of corrosion current density compared to intact NC control specimens), leading to higher corrosion resistance for SMA-ECC according to the electrochemical test results.