Electrochemical behavior of mild and corrosion resistant concrete reinforcing steels

Sohail, Muazzam Ghous; Kahraman, Ramazan; Al‐Nuaimi, Nasser; Gencturk, Bora; Alnahhal, Wael; Dawood, Mina; Belarbi, Abdeldjelil

doi:10.1016/j.conbuildmat.2019.117205

Cited by 67 publications

(34 citation statements)

References 36 publications

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“…This is attributed to the inhibitor molecule adsorbed on the metal surface, which replaces the adsorbed water molecules. Moreover, the model describes the localized breakdown mechanism of the passive www.nature.com/scientificreports/ layer, which takes place because of the competitive adsorption of the Cland OHions, which are inhibited in the presence of Q-32 68,69 . The increase in the charge transfer resistance values may be attributed to either (i) the formed passive film, which is promoted by the presence of the inhibitor molecules that block the active sites on the steel surface, according to Uhlig and Bohni 70,71 , or (ii) the increase in the adsorbed layer thickness/area of the inhibitor, which acts as a physical barrier.…”

Section: Resultsmentioning

confidence: 99%

An efficient green ionic liquid for the corrosion inhibition of reinforcement steel in neutral and alkaline highly saline simulated concrete pore solutions

Sliem

Radwan

Mohamed

et al. 2020

Sci Rep

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The effect of the green ionic liquid compound, Quaternium-32 (Q-32), on the corrosion inhibition performance of reinforcement steel, in a simulated concrete pore solution, was investigated at different temperatures and pH values, using electrochemical impedance spectroscopy (EIS). The inhibition efficiency was improved as the concentration of Q-32 and pH values were increased. However, it decreased as the temperature was raised. A Q-32 concentration of 20 µmol L-1 exhibited a 94% inhibition efficiency at 20 °C. The adsorption isotherm was evaluated using EIS measurements, and it was found to obey the Langmuir isotherm. The surface topography was examined using an atomic force microscope and scanning electron microscope. The effect of the Q-32 concentration with the highest corrosion efficiency on the mechanical properties of the mortars was also explained by flexure and compression techniques. Reinforced concrete is utilized in most structures, such as buildings and bridges, because of its excellent service and easy maintenance. Reinforcement steel in concrete structures, especially those exposed to marine and industrial environments, can suffer from corrosion due to many factors, such as pH reduction, carbonation, and chloride attack 1-3. The chloride content is considered to be one of the main reasons for decreases in the strength of concrete structures. Once the chloride concentration around the steel bar reaches a threshold value, an early structural deterioration takes place 4,5. The simulated concrete pore solution (SCPS) method is commonly utilized in accelerated tests to investigate the corrosion behavior of the steel in concrete. However, it suffers from some errors due to the heterogeneity in the actual concrete, unlike the simulated one. The common SCPS contains saturated Ca(OH) 2 6-9 or cement extract solution 10-13. It is well known that steel forms a passive layer in SCPS, with a pH ranging from 9.5 to 12. This passive layer becomes unstable and cannot protect it from corrosion when the pH drops below 9.5 14,15. Several preventive techniques have been proposed and tested to stop or mitigate the corrosion of reinforcement steel. For example, galvanization, epoxy coating, cathodic protection and concrete sealing, in addition to the superplasticizer addition and use of corrosion inhibitors, are among the practices to control the corrosion of reinforcement steel 16-18. The corrosion inhibitor efficiency in SCPS has been studied by many researchers 19-26. Most of these studies focus on the adequate dosage of the corrosion inhibitors to provide sufficient inhibition protection for reinforcement steel. However, most of them do not investigate the mechanical properties of the concrete in the presence of the corrosion inhibitor. Corrosion inhibitors in concrete are divided into organic materials, such as alkanolamine and its salts 27,28 , organic acid salt mixtures 29 and inorganic substances, mainly nitrites. However, nitrites are currently banned in many countries due to their carcinogenicity and biologica...

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Section: Resultsmentioning

confidence: 99%

An efficient green ionic liquid for the corrosion inhibition of reinforcement steel in neutral and alkaline highly saline simulated concrete pore solutions

Sliem

Radwan

Mohamed

et al. 2020

Sci Rep

Self Cite

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“…As curvas geradas pelo EIS apresentam comportamentos semelhantes para ambos os concretos, sendo curvas representativas para materiais cimentícios (VENDALAKSHMI et al, 2009;BRAGANÇA et al, 2014;SOHAIL et al, 2020).…”

Section: Análise Eletroquímicaunclassified

Estudo Do Comportamento Eletroquímico Do Concreto Auto Adensável E Do Concreto Convencional Submetidos a Ciclos De Secagem E Molhagem Exposto Ao Ataque De Cloretos

Tabarelli¹,

Garcez²,

Trein³

et al. 2020

≫Congresso Brasileiro De Patologia Das Construções

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O Concreto Auto Adensável (CAA) é considerado uma inovação de sucesso na construção civil e proporciona um material mais compacto, com menos poros, sendo considerado uma evolução da tecnologia do concreto. O CAA vem sendo bastante utilizado no Japão e na Europa, mas no Brasil, sua utilização ainda é pequena e são poucos os estudos existentes frente ao comportamento do CAA referente a melhorias principalmente no quesito durabilidade. A corrosão do aço ainda é o principal fator de degradação do concreto armado. A resistividade elétrica do concreto é uma propriedade sensível ao processo eletroquímico que gera a corrosão das armaduras. O presente trabalho tem objetivo avaliar a resistividade elétrica através da técnica de espectroscopia de impedância eletroquímica de dois tipos de concretos de cimento Portland expostos à cloretos: o concreto convencional (CC) e o concreto auto adensável (CAA). O programa experimental consta de corpos de prova de mesma classe de resistência e mesma relação água/cimento, submetidos a ciclos de secagem e molhagem em solução de cloretos por um período de dois anos. Os resultados demostram uma variação na resistividade elétrica onde o CAA possui uma resistividade superior (90%), e uma degradação inferior (25%) se comparada com o concreto convencional.

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“…However, the rebar must be partially exposed in these methods, which also require more time for inspections. As simple non-destructive inspection (NDI) methods, electric impedance methods [ 8 , 9 , 10 ] and eddy current testing [ 11 , 12 , 13 ] are proposed for evaluation of rebar corrosion, but it is difficult to evaluate the quantitative corrosion loss of the rebar in practical situations. Thermal imaging inspection [ 14 , 15 ] is a non-destructive method that can quickly indicate delamination by examining changes in infrared radiation emitted from the surface of concrete.…”

Section: Introductionmentioning

confidence: 99%

Non-Destructive and Quantitative Evaluation of Rebar Corrosion by a Vibro-Doppler Radar Method

Miwa

2021

Sensors

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It is well known that evaluation of rebar corrosion is important for the maintenance of reinforced concrete structures, but, it is difficult to simply, quickly and quantitatively evaluate the amount of corrosion of rebars embedded in concrete by conventional non-destructive evaluation (NDE) methods such as electrical, electromagnetic and mechanical method. This paper proposes a vibro-Doppler radar (VDR) measurement method to quantitatively evaluate rebar corrosion by measuring the vibration ability of the rebar forcibly vibrated in concrete by an excitation coil. It is experimentally demonstrated in RC test pieces that the rebar vibration displacement obtained by developed VDR method is valid and is less affected by the moisture in the concrete. In addition, simultaneous monitoring of the rebar vibration displacement of the test pieces is performed through an electrolytic corrosion test and the measured vibration displacement is compared to the rebar corrosion loss evaluated. As the results, it is cleared that the rebar vibration displacement starts to increase from slightly before the occurrences of corrosion crack on the concrete surface as the corrosion loss increases. It is also shown that the rebar vibration displacement becomes 4 times higher than that in initial condition at the rebar corrosion loss of 250 mg/cm2. This implies that the VDR has potential to nondestructively and quantitatively evaluate rebar corrosion in concrete.

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Electrochemical behavior of mild and corrosion resistant concrete reinforcing steels

Cited by 67 publications

References 36 publications

An efficient green ionic liquid for the corrosion inhibition of reinforcement steel in neutral and alkaline highly saline simulated concrete pore solutions

An efficient green ionic liquid for the corrosion inhibition of reinforcement steel in neutral and alkaline highly saline simulated concrete pore solutions

Estudo Do Comportamento Eletroquímico Do Concreto Auto Adensável E Do Concreto Convencional Submetidos a Ciclos De Secagem E Molhagem Exposto Ao Ataque De Cloretos

Non-Destructive and Quantitative Evaluation of Rebar Corrosion by a Vibro-Doppler Radar Method

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