Corrosion macrocell behavior of reinforcing steel in partially submerged concrete columns

Sagüés, Alberto A.; Pech‐Canul, M. A.; Al-Mansur, Akm

doi:10.1016/s0010-938x(02)00087-2

Cited by 68 publications

(38 citation statements)

References 36 publications

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“…The first time constant deals with the charge transfer resistance and pseudodouble layer capacitance ͑R ct and Q ct , respectively͒; the second time constant is related to redox transformations, mainly Fe 2+ /Fe 3+ , in the surface layers ͑R red and Q red , respectively͒. The replacement of pure capacitance ͑C͒ with constant phase element ͑CPE or Q͒ in the equivalent circuits is widely accepted for systems as in this study, [56][57][58][59] being denoted to inhomogeneities at different levels, hereby being mainly relevant to the heterogeneity of hydration/ corrosion products that form on the steel surface, in addition to the participation of micelles in the product layer formation. The CPE is an empirical mathematical description of the observed impedance response and is defined as 52 : Z = ͑j͒ −n /Y 0 , being further quantified by the parameters Y 0 and n ͑CPE constant and CPE factor, respectively͒, where Y 0 is a parameter with units ⍀ −1 s n and 0 Ͻ n ഛ 1.…”

Section: Resultsmentioning

confidence: 99%

Corrosion Performance of Carbon Steel in Simulated Pore Solution in the Presence of Micelles

Koleva

Wit

et al. 2011

J. Electrochem. Soc.

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This study presents the results on the investigation of the corrosion behavior of carbon steel in model alkaline medium in the presence of very low concentration of polymeric nanoaggregates ͓0.0024 wt % polyethylene oxide ͑PEO͒ 113 -b-PS 70 micelles͔. The steel electrodes were investigated in chloride-free and chloride-containing cement extracts. The electrochemical measurements ͑electrochemical impedance spectroscopy and potentiodynamic polarization͒ indicate that the presence of micelles alters the composition of the surface layers ͑i.e., micelles were indeed absorbed to the steel surface͒ and influences the electrochemical behavior of the steel, i.e., the micelles lead to an initially increased corrosion resistance of the steel whereas no significant improvement was observed within longer immersion periods. Surface analysis, performed by environmental scanning electronic microscopy, energy-dispersive x-ray analysis, and x-ray photoelectron spectroscopy, supports and elucidates the corrosion performance. The product layers in the micelles-containing specimens are more homogenous and compact, presenting protective ␣-Fe 2 O 3 and/or Fe 3 O 4 , whereas the product layers in the micelles-free specimens exhibit mainly FeOOH, FeO, and FeCO 3 , which are prone to chloride attack. Therefore, the increased "barrier effects" along with the layers composition and altered surface morphology denote for the initially increased corrosion resistance of the steel in chloride-containing alkaline medium in the presence of micelles. A well-known fact is that corrosion of steel reinforcement can cause reinforced concrete deterioration and thus affect civil structures durability.1,2 Logically, corrosion-related issues result in a significant economic loss. For example, in the United States, the annual direct cost of bridge infrastructure corrosion was estimated to be $8.3 billion, and the indirect cost was reported to be many times higher. 3In normal conditions, the reinforcing steel embedded in cementbased materials ͑i.e., cement paste, mortar, and concrete͒ is in a passive state because of the high alkalinity ͑pH = 12.6-13.5͒ of the pore solution and the cement paste, respectively. 4,5 However, corrosion can be initiated due to carbonation or chloride contamination. 6 Carbonation can result in a pH drop ͑to about 8-9͒ 7,8 in the pore solution of the bulk cementitious matrix, leading to a general corrosion of the reinforcing steel. In the event of chloride penetration and chloride arrival at the steel/cement paste interface, localized corrosion is initiated; the local pH can drop to even below 6, resulting in fast corrosion propagation. This will cause accelerated damage of the reinforcing steel and possible rapid failure of reinforced concrete. 9To minimize the corrosion processes, various methods and techniques are used. Among them, the polymer-based organic corrosion inhibitors are widely applied because they can provide an easy handling, cost-effective corrosion prevention, delaying corrosion initiation.10-14 The organic inh...

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Section: Resultsmentioning

confidence: 99%

Corrosion Performance of Carbon Steel in Simulated Pore Solution in the Presence of Micelles

Koleva

Wit

et al. 2011

J. Electrochem. Soc.

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“…If that corrosion actually occurred in service, the previous discussion suggests that initiation took place relatively recently, so typical corrosion propagation rates may be in the micrometer per year range (barely above usual estimates of passive corrosion rates). (19) This modest range estimate is not surprising considering that the concrete in the piles, even when wet, had high resistivity (reflecting low pore connectivity and often moderate internal humidity), of a level commonly associated with very low or negligible corrosion rates. In the wetter parts of the substructure oxygen diffusivity would be expected to be low, further lowering the overall corrosion rate.…”

Section: Corrosion Propagation Ratesmentioning

confidence: 95%

Corrosion Performance of Concrete Cylinder Piles

Lau¹,

Sagüés²,

Yao³

et al. 2007

CORROSION

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Concrete cylinder piles produced by a centrifugally cast, vibrated, roller-compacted process have shown promising corrosion resistance in marine environments. Three bridges in the Florida panhandle with ~40 years in aggressive marine service and one newly constructed marine bridge utilizing concrete cylinder piles were examined. Examination of the older marine bridges showed minimal corrosion distress despite low design concrete cover over the steel hoop reinforcement (2-4 cm). Typical concrete distress included minor rust staining (not necessarily indicating corrosion of reinforcement steel) and thin longitudinal cracks (likely caused by mechanical damage from pile driving). Chloride ion diffusivity was low, in the order of 1x10 -9 cm 2 /s. Other measured parameters such as concrete resistivity, porosity, and water absorption indicate low permeability. Chloride analysis of cracked and uncracked concrete cores from the older bridges in this study did not show pronounced preferential chloride penetration. Chloride analysis from the contemporary marine bridge did show some preferential transport of chloride ions at shallow depths through cracks with further evidence of lower electrical resistivity indicating enhanced electrolyte transport. Simplified corrosion durability modeling projections indicate that a moderate relaxation of a current 7.6 cm cover requirement may be made without significantly compromising the service life requirements of cylinder piles.

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“…The elements of the equivalent circuit present the following physical meanings: R el?b is the mortar resistance, including the contribution of the electrolyte resistance; the first time constant (R pn and Q pn ) is attributed to the properties of the bulk matrix in terms of connected pore network; the second time constant (Q ct and R ct ) is normally used to evaluate charge transfer process in combination with mass transport process. When there are no mass transport limitations, R ct equals the global polarization resistance R p [35,45] and is related to the electrochemical reaction on the steel surface (widely accepted for reinforced cement-based materials is to use constant phase element (Q) instead of pure capacitance to account for steel surface, product layers, and bulk matrix heterogeneity [49,50]). …”

Section: Electrochemical Impedance Spectroscopy (Eis)mentioning

confidence: 99%

Corrosion performance of reinforced mortar in the presence of polymeric nano-aggregates: electrochemical behavior, surface analysis, and properties of the steel/cement paste interface

Koleva

Breugel

2012

J Mater Sci

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This study reports on the effect of admixed polyethylene oxide-b-polystyrene (PEO 113 -b-PS 70 ) micelles on corrosion behavior of reinforced mortar. The electrochemical measurement shows that the corrosion performance of the reinforcing steel was not significantly improved. However, surface analysis and microstructural investigation at the steel/cement paste interface reveal that the admixed micelles lead to a steel surface layer with enhanced barrier properties in terms of morphology and composition. Therefore, the presence of micelles further minimized and halted the corrosion process, despite the very aggressive, chloride-containing environment of 5% NaCl. The reasons and mechanisms behind the hereby observed corrosion behavior of reinforced mortar in the presence of micelles are related to the influence of these nano-aggregates on microstructural properties. These further results in altered water/ion transport and chloride-binding mechanisms in the bulk mortar matrix and thus steel product layer modifications towards enhanced corrosion resistance.

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Corrosion macrocell behavior of reinforcing steel in partially submerged concrete columns

Cited by 68 publications

References 36 publications

Corrosion Performance of Carbon Steel in Simulated Pore Solution in the Presence of Micelles

Corrosion Performance of Carbon Steel in Simulated Pore Solution in the Presence of Micelles

Corrosion Performance of Concrete Cylinder Piles

Corrosion performance of reinforced mortar in the presence of polymeric nano-aggregates: electrochemical behavior, surface analysis, and properties of the steel/cement paste interface

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