Chloride ingress and steel corrosion in geopolymer concrete based on long term tests

Tennakoon, Chandani; Shayan, A; Sanjayan, Jay; Xu, Aiguo

doi:10.1016/j.matdes.2016.12.030

Cited by 162 publications

(61 citation statements)

References 37 publications

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“…Results of One-way ANOVA for crack spacing are listed in Table 9. From Tables 7-9, it can be concluded that F-values of crack width and crack number are larger than F 0.01 (3,8), which means the probability is 99% that crack width and crack number present a significant influence of rebar corrosion. Meanwhile, F-value of crack number is larger than that of crack width, which means the influence of crack number is larger than crack width.…”

Section: The Effect Of Crack On Corrosion Behavior Of Rebarmentioning

confidence: 93%

“…Besides, cracks provide a convenient channel for water ingression, harmful ions and oxygen towards the internal concrete and the surface of rebar, which could result in accelerating corrosion of rebar. Therefore, it is necessary to investigate corrosion behavior of rebar under the effect of crack in chloride aggressive environment [5][6][7][8].…”

Section: Introductionmentioning

confidence: 99%

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Effect of Crack on Durability of RC Material under the Chloride Aggressive Environment

et al. 2018

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Exposed to aggressive environments, the rebar in reinforced concrete (RC) bridges will be corroded gradually. Durability of RC material mostly depends on the rebar corrosion behavior. In this research, influences of crack on rebar corrosion were investigated. Firstly, RC specimens with different crack number, width and spacing were prepared and the rebar corrosion was conducted through an accelerated chloride penetration method. Then, corrosion current densities of rebar were calculated from electrochemical test methods including liner polarization (LP), Tafel potentiodynamic polarization (TPP) and electrochemical impedance spectroscopy (EIS) measurements. Finally, the discussion was presented about a more reasonable electrochemical testing method for rebar corrosion in RC material. Besides, the significant influence factor among crack width, number and spacing was evaluated based on both One-way analysis of variance (One-way ANOVA) and Turkey's honest significant difference (Turkey's HSD) test. The results revealed that a more reasonable way to obtain corrosion current densities of rebar is combining EIS measurement with TPP measurement. Crack number shows the most significant effect on corrosion behavior of rebar, while crack spacing possesses the least one.

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Section: The Effect Of Crack On Corrosion Behavior Of Rebarmentioning

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Effect of Crack on Durability of RC Material under the Chloride Aggressive Environment

et al. 2018

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“…Therefore, elemental sulfur could play a role in inhibiting pitting corrosion only if sufficient oxygen is available at the SCI. Higher corrosion rates [48], higher i corr and lower R p values [42,49] have been reported for steel-reinforced AAS exposed to chloride solutions in comparison to those observed in PC. However, visual examination of the steel rebars in each of these studies found that the extent of corrosion for steel embedded in AAS was much lower than those in PC, for instance, no evidence of corrosion was observed by Criado et al [42], Fig.5, which contrasts strongly with the electrochemical observations.…”

Section: Binders With a Reducing Internal Environmentmentioning

confidence: 99%

Steel corrosion in reinforced alkali-activated materials

et al. 2017

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The development of alkali-activated materials (AAMs) as an alternative to Portland cement (PC) has seen significant progress in the past decades. However, there still remains significant uncertainty regarding their long term performance when used in steel-reinforced structures. The durability of AAMs in such applications depends strongly on the corrosion behaviour of the embedded steel reinforcement, and the experimental data in the literature are limited and in some cases inconsistent. This letter elucidates the role of the chemistry of AAMs on the mechanisms governing passivation and chloride-induced corrosion of the steel reinforcement, to bring a better understanding of the durability of AAM structures exposed to chloride. The corrosion of the steel reinforcement in AAMs differs significantly from observations in PC; the onset of pitting (or the chloride 'threshold' value) depends strongly on the alkalinity, and the redox environment, of these binders. Classifications or standards used to assess the severity of steel corrosion in PC appear not to be directly applicable to AAMs due to important differences in pore solution chemistry and phase assemblage.

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“…These considerations, therefore, support use of the Weibull distribution as the descriptive statistics for detailing the corrosion test-results in this study. 2 Admixtures. The results of inhibition efficiency on reinforcing-steel corrosion, obtained by subjecting the Weibull mean of corrosion-rate to (8), are plotted in Figure 3, according to the ranking order of C. citratus leaf-extract and NaNO 2 admixture performance.…”

Section: Modelled Results Of Corrosion Test-data By Statisticalmentioning

confidence: 99%

“…Corrosion of reinforcing-steel by chloride ion ingress into concrete from saline (via artificial deicing salt usage in temperate regions) or marine (via natural seawater from coastal areas) environments is a major degradation mechanism affecting steel-reinforced concrete durability [1][2][3][4]. This is because chloride ion breaks the thin film of passive oxide layer protecting reinforcing-steel in the highly alkaline concrete pore environment, which, until the aggressive chloride ion ingression, had kept the steel embedment depassivated [5][6][7].…”

Section: Introductionmentioning

confidence: 99%

Cymbopogon citratusand NaNO₂Behaviours in 3.5% NaCl-Immersed Steel-Reinforced Concrete: Implications for Eco-Friendly Corrosion Inhibitor Applications for Steel in Concrete

Okeniyi

Popoola

Okeniyi

2018

International Journal of Corrosion

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This paper studies behaviours of Cymbopogon citratus leaf-extract and NaNO 2 , used as equal-mass admixture models, in 3.5% NaCl-immersed steel-reinforced concrete by nondestructive electrochemical methods and by compressive-strength improvement/reduction effects. Corrosion-rate, corrosion-current, and corrosion-potential constitute electrochemical test-techniques while compressive-strength effect investigations followed ASTM C29 and ASTM C33, in experiments using positive-controls for the electrochemical and compressive-strength studies. Analyses of the different electrochemical test-results mostly portrayed agreements on reinforcing-steel anticorrosion effects by the concentrations of natural plant and of chemical admixtures in the saline/marine simulating-environment and in the distilled H 2 O (electrochemical positive control) of steel-reinforced concrete immersions. These indicated that little amount (0.0833% cement for concrete-mixing) of Cymbopogon citratus leaf-extract was required for optimal inhibition efficiency, = 99.35%, on reinforcing-steel corrosion, in the study. Results of compressive-strength change factor also indicated that the 0.0833% Cymbopogon citratus concentration outperformed NaNO 2 admixture concentrations also in compressive-strength improvement effects on the NaCl-immersed steel-reinforced concrete. These established implications, from the study, on the suitability of the eco-friendly Cymbopogon citratus leaf-extract for replacing the also highly effective NaNO 2 inhibitor of steel-in-concrete corrosion in concrete designed for the saline/marine service-environment.

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Chloride ingress and steel corrosion in geopolymer concrete based on long term tests

Cited by 162 publications

References 37 publications

Effect of Crack on Durability of RC Material under the Chloride Aggressive Environment

Effect of Crack on Durability of RC Material under the Chloride Aggressive Environment

Steel corrosion in reinforced alkali-activated materials

Cymbopogon citratusand NaNO₂Behaviours in 3.5% NaCl-Immersed Steel-Reinforced Concrete: Implications for Eco-Friendly Corrosion Inhibitor Applications for Steel in Concrete

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Chloride ingress and steel corrosion in geopolymer concrete based on long term tests

Cited by 162 publications

References 37 publications

Effect of Crack on Durability of RC Material under the Chloride Aggressive Environment

Effect of Crack on Durability of RC Material under the Chloride Aggressive Environment

Steel corrosion in reinforced alkali-activated materials

Cymbopogon citratusand NaNO2Behaviours in 3.5% NaCl-Immersed Steel-Reinforced Concrete: Implications for Eco-Friendly Corrosion Inhibitor Applications for Steel in Concrete

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Cymbopogon citratusand NaNO₂Behaviours in 3.5% NaCl-Immersed Steel-Reinforced Concrete: Implications for Eco-Friendly Corrosion Inhibitor Applications for Steel in Concrete