Journal articles on the topic 'Reinforced concrete – Corrosion'
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Hernández, Y., O. Troconis de Rincón, A. Torres, S. Delgado, J. Rodríguez, and O. Morón. "Relación entre la velocidad de corrosión de la armadura y el ancho de fisuras en vigas de concreto armado expuestas a ambientes que simulan el medio marino." Revista ALCONPAT 6, no. 3 (September 30, 2016): 272–83. http://dx.doi.org/10.21041/ra.v6i3.152.
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Relación entre la velocidad de corrosión de la armadura y el ancho de fisuras en vigas de concreto armado expuestas a ambientes que simulan el medio marino RESUMENEsta investigación presenta una relación empírica entre la velocidad de corrosión de la armadura y la velocidad de ensanchamiento de fisuras por corrosión del recubrimiento de concreto en vigas, con o sin aplicación de carga. Se evaluaron vigas de concreto armado, expuestas a un proceso de corrosión natural mediante el rociado con solución salina al 3,5 %p/p de NaCl, para acelerar el proceso corrosivo de la armadura, mediante ensayos electroquímicos. El ancho de fisuras se evaluó mensualmente para estimar la relación existente entre éste y la pérdida de sección de la armadura. Los resultados demuestran que existe una relación directa entre la propagación del ancho de fisuras y la velocidad de corrosión, observando fisuras de mayor ancho en vigas cargadas.Palabras clave: corrosion; concreto armado; vigas cargadas; ancho de fisuras. Reinforcement corrosion rate and crack width relationship in concrete beams exposed to simulated marine environment ABSTRACTThis investigation presents an empirical correlation between the rebar corrosion rate and the corrosion-induced crack width propagation rate produced on beam's concrete cover, with or without load application to these beams. Reinforced concrete beams were evaluated, exposed to a natural corrosion process by spraying with 3.5 %w/w NaCl solution, to accelerate the rebar corrosion process, was performed with electrochemical tests. The beams corrosion-cracking evaluation was performed once every month, to determine the relation between crack width and the rebar corrosion loss. The results showed a direct relation between crack width propagation and rebar corrosion rate, showing wider cracks in the loaded beams.Keywords: corrosion; reinforced concrete; loaded beams; crack widths. Relação entre a velocidade de corrosão da armadura e a largura das fissuras em vigas de concreto armado expostas a ambientes que simulam o ambiente marinho RESUMOEsta pesquisa apresenta uma relação empírica entre a taxa de corrosão da armadura e a abertura de fissuras por efeito da corrosão da armadura em vigas de concreto, com ou sem aplicação de carga. Foram avaliadas vigas de concreto armado, expostas a um processo de corrosão natural por pulverização com solução salina a concentração de 3,5% de NaCl, para acelerar o processo de corrosão da armadura, mediante ensaios eletroquímicos. A abertura das fissuras foi avaliada mensalmente para estimar a relação entre ela e a perda de seção da armadura. Os resultados mostram que existe uma relação direta entre a propagação da abertura da fissura e a taxa de corrosão, observando a ocorrência de fissuras de maior abertura nas vigas sob carga.Palavras-chave: corrosão; vigas de concreto armado sob carga; abertura de fissuras.
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Anandan, Sivakumar, Sounthararajan Vallarasu Manoharan, and Thirumurugan Sengottian. "Corrosion Effects on the Strength Properties of Steel Fibre Reinforced Concrete Containing Slag and Corrosion Inhibitor." International Journal of Corrosion 2014 (2014): 1–7. http://dx.doi.org/10.1155/2014/595040.
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Corrosion in steel can be detrimental in any steel rebar reinforced concrete as well as in the case of steel fibre reinforced concrete. The process of corrosion occurring in steel fibre incorporated concrete subjected to corrosive environment was systematically evaluated in this study. Concrete specimens were prepared with steel fibre inclusions at 1.5%Vf(volume fraction) of concrete and were added in slag based concrete (containing manufactured sand) and replaced with cement at 20%, 40%, and 60% of total binder. Accelerated corrosion studies were carried out using alternate wetting and drying cycle accompanied with initial stress at 40% and 60% of ultimate stress. Concrete specimens were then immersed in chloride-free water and sodium chloride solution (3.5%) after subjecting to initial stress. The alternate wetting and drying process of different concrete mixes was continued for longer exposure (6 months). Later, the strength degradation during the accelerated corrosion process was then assessed in compressive and flexural tests. Test results indicated that the strength degradation was marginal in the case of steel fibre reinforced concrete containing higher slag content and for the concretes containing corrosion inhibitors. The maximum strength reduction was noticed in the case of plain concrete containing steel fibres and, with the slag addition, a considerable reduction in corrosion potential was noticed. Also, with the increase in slag replacement up to 60%, a significant increase in strength was noticed in flexural test. Experimental test results also showed that the corrosion process in steel fibre reinforced concrete can be controlled with the incorporation of corrosion inhibitors in cementitious system.
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Дронов and Andrey Dronov. "THE PROPERTIES OF PITTING CORROSION OF STEEL REINFORCEMENT OF REINFORCED CONCRETE BEAMS." Bulletin of Belgorod State Technological University named after. V. G. Shukhov 2, no. 3 (April 4, 2017): 32–36. http://dx.doi.org/10.12737/24678.
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Two types of steel reinforcement depassivation process: carbonation of concrete and chloride penetration are considered in the article. The comparison between the corrosion due to carbonation of concrete and the chloride-induced corrosion was carried out. It was found out, that chlorides induced corrosion is potentially more dangerous than that resulting from carbonation. Method of durable tests of reinforced concrete structures under the action of the gravitational load and the corrosive chloride environment is described in the article. The results of experimental research on reinforced concrete structures with corrosive damages to steel reinforcement are given in the article. The properties of corrosion cracking in the case of the pitting corrosion were determined. The character of corrosive damage distribution along the reinforcement bars and its effect on the strength of reinforced concrete beams were determined.
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Meneses, R. S., J. M. Moro, R. R. Aveldaño, and N. F. Ortega. "Influencia del espesor del recubrimiento de elementos de hormigón armado expuestos a procesos de corrosión y sometidos a cargas externas." Revista ALCONPAT 6, no. 2 (May 31, 2016): 129–44. http://dx.doi.org/10.21041/ra.v6i2.134.
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Influencia del espesor del recubrimiento de elementos de hormigón armado expuestos a procesos de corrosión y sometidos a cargas externasRESUMENAl realizar estudios sobre corrosión en hormigón armado, es importante considerar en los ensayos, la acción de cargas externas, pues esta situación es la más frecuente en las estructuras. En este trabajo, se presentan los resultados obtenidos al exponer a un proceso de corrosión acelerada, a vigas de hormigón armado sometidas a esfuerzos flexionales, materializados con cargas, que generan iguales tensiones de tracción en las armaduras corroídas. Las vigas se fabricaron con diferentes espesores de recubrimiento de las armaduras y con un hormigón de resistencia característica 25 MPa. Este estudio pone en evidencia la influencia del espesor de recubrimiento de las armaduras, sobre el proceso de corrosión y su manifestación externa (fisuración del recubrimiento), frente a las mismas solicitaciones mecánicas.Palabras claves: corrosión de armaduras traccionadas; recubrimiento; fisuración. Influence of the thickness of the coating of the elements of reinforced concrete exposed to corrosion processes and subjected to external loadsABSTRACTWhen studies are done in reinforced concrete, it is important to consider the action of external loads, since that is the most common situation in structures. In this study we present the results of exposing reinforced concrete beams to a process of accelerated corrosion, while under bending stresses caused by loads that generate equal tensile stresses on the corroded reinforcements. The beams were built with different cover thicknesses over the reinforcements, and with a 25 MPa characteristic resistance concrete. This study shows the influence of the cover thickness over the corrosion process and its external manifestation (cover cracking), under the same mechanical stress.Keywords: tension corrosion reinforcement; cover; cracking. Influência da espessura de cobrimento dos elementos de concreto armado expostos a processos de corrosão e submetidos a cargas externasRESUMOAo realizar estudos sobre corrosão em concreto armado, é importante considerar nos ensaios a ação de cargas externas, pois esta situação é mais frequente nas estruturas. Neste artigo apresentam-se os resultados obtidos ao expor vigas de concreto armado a um processo de corrosão acelerada, submetidas a esforços de flexão materializados com cargas que geram tensões constantes de tração nas armaduras corroídas. As vigas foram elaboradas com diferentes espessuras de cobrimento das armaduras e com um concreto de resistência característica de 25MPa. Este estudo coloca em evidência a influência da espessura de cobrimento das armaduras, sobre o processo de corrosão e sua manifestação externa (fissuração do cobrimento), frente às mesmas solicitações mecânicas.Palavras-chave: corrosão de armaduras tracionadas; cobrimento; fissuração.
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Qin, Xian Ming, Chao Yan, Yue Li, and Juan Zhao. "Influence of Corrosion Inhibitor on Marine Concrete Corrosion Rate." Advanced Materials Research 446-449 (January 2012): 3508–12. http://dx.doi.org/10.4028/www.scientific.net/amr.446-449.3508.
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Corrosion inhibitor have a significant influence on corrosion rate of marine concrete. In this paper, linear polarization method is used in reinforced concrete that under marine environment, and reinforced concrete is mixed with corrosion inhibitor. The results show that: corrosion inhibitor has a little influence on the basic mechanical properties of reinforced concrete, and it can effectively improve the corrosion resistance ability of reinforced concrete. For reinforced concrete of the same corrosion inhibitor content, with the decline of water-cement ratio, the steel corrosion rate descends; in a certain content range , with the increase of corrosion inhibitor content, the corrosion rate of reinforced concrete decreases evidently.
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Pepenar, Ioan. "Corrosion behaviour of reinforced concrete constructions in acid aggressive environments: case studies, laboratory tests and corrosion mechanisms." MATEC Web of Conferences 149 (2018): 01018. http://dx.doi.org/10.1051/matecconf/201814901018.
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The paper presents the results of research on the corrosion behaviour of reinforced concrete elements which compose the bearing structure of some constructions subjected to the corrosive action of acid aggressive agents, after a long-term service in a strongly aggressive environment. To evaluate the damage state of reinforced concrete elements/constructions, both “in situ” investigation of constructions and laboratory tests on concrete samples extracted from some elements damaged by corrosion, using a specific investigation methodology were performed. The results of the research revealed the existence of a severe corrosion-induced damage of the structural elements, which affected the resistance, stability and durability of the constructions. Based on case studies on the service behaviour of reinforced concrete elements, there are pointed out the specific damages generated by the corrosive action of the acid aggressive agents, the causes of their occurrence and presents considerations on the mechanisms of the corrosion processes of concrete and steel reinforcement in acid aggressive environments. Finally, there were proposed intervention measures in order to assure normal service conditions of the reinforced concrete constructions located in such aggressive environments.
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Almeraya, Facundo, José Maria Bastidas, Andres A. Torres Acosta, and Citlalli Gaona Tiburcio. "Corrosion in Reinforced Concrete." International Journal of Corrosion 2012 (2012): 1. http://dx.doi.org/10.1155/2012/986186.
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Okeniyi, Joshua Olusegun, Isaac Oluwaseun Oladele, Oluwafemi Michael Omoniyi, Cleophas Akintoye Loto, and Abimbola Patricia Idowu Popoola. "Inhibition and compressive-strength performance of Na2Cr2O7 and C10H14N2Na2O8·2H2O in steel-reinforced concrete in corrosive environments." Canadian Journal of Civil Engineering 42, no. 6 (June 2015): 408–16. http://dx.doi.org/10.1139/cjce-2014-0364.
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This paper studied corrosion-inhibition and compressive-strength performances of Na2Cr2O7 (sodium dichromate) and C10H14N2Na2O8·2H2O (ethylenediaminetetraacetic disodium salt: EDTA-Na2) admixtures in steel-reinforced concrete immersed in NaCl and in H2SO4 corrosive environments. Electrochemical methods were used for studying corrosion responses of different concentrations of the individual admixtures and their synergies, in the model that partially replace the toxic Na2Cr2O7 by the environmentally-friendly C10H14N2Na2O8·2H2O, in steel-reinforced concretes. After the electrochemical experiment, the steel-reinforced concrete samples were subjected to the compressive-strength testing and analyses of ASTM C39/C39M-03 and ASTM C267-01(2012). Results showed that the use of environmentally-friendly EDTA-Na2 for partially replacing toxic Na2Cr2O7 chemical exhibited better corrosion-inhibition and compressive-strength improvement in the NaCl-immersed concretes, than in the H2SO4-immersed concretes. The 2 g Na2Cr2O7 + 6 g EDTA-Na2 admixture (representing partial replacement model of 6 g Na2Cr2O7 by 6 g EDTA-Na2) exhibited optimal corrosion inhibition efficiency (η = 99.0%) and very good compressive-strength improvement advantage in the NaCl-immersed concretes. In contrast, comparatively low compressive-strength reduction trade-off with the good inhibition effectiveness of η = 79.9% support use of 6 g EDTA-Na2 admixture only (i.e., without Na2Cr2O7 addition) for inhibiting reinforcing-steel corrosion in the H2SO4-immersed concretes.
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Mirsayapov, Ilshat, Samat Yakupov, and Majd Hassoun. "About concrete and reinforced concrete corrosion." IOP Conference Series: Materials Science and Engineering 890 (August 13, 2020): 012061. http://dx.doi.org/10.1088/1757-899x/890/1/012061.
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Wasim, Muhammad, Rajeev Roychand, Rhys Barnes, Jason Talevski, David Law, Jie Li, and Mohammad Saberian. "Performance of Reinforced Foam and Geopolymer Concretes against Prolonged Exposures to Chloride in a Normal Environment." Materials 16, no. 1 (December 23, 2022): 149. http://dx.doi.org/10.3390/ma16010149.
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The utilization of sustainable cement replacement materials in concrete can control the emission of carbon dioxide and greenhouse gases in the construction industry, thus contributing significantly to the environment, society, and the global economy. Various types of sustainable concrete including geopolymer concrete are tested for their efficacy for construction in laboratories. However, the performance and longevity of sustainable concrete for civil engineering applications in corrosive environments are still debatable. This paper aims to investigate the performance of the reinforced geopolymer (GPC) and foam concretes (FC) against corrosive chloride exposure. Two long term key parameters, i.e., corrosion rate and mechanical performance of reinforcing steel in geopolymer and foam concrete were assessed to evaluate their performance against chloride attack. For experiments, reinforced GPC and FC specimens, each admixed with 3 and 5% chlorides, were kept at varying temperatures and humidity levels in the environmental chambers. The corrosion rates of the reinforced geopolymer and foam concrete specimens were also compared with control specimens after 803 days and the tensile strength of the corroded reinforcing steel was also determined. Moreover, the long term efficacy of repaired patches (810 days), in a chloride-rich surrounding environment utilizing FC and GPC, was investigated. The results suggested greater performance of FC compared to GPC under standard environmental conditions. However, the simulated patch repair with GPC showed better resistance against chloride attack compared to FC. The research also undertook the fractographical examination of the surfaces of the reinforcement exposed to 5% admixed chloride and develops models for the corrosion rates of foam concrete as a function of the corrosion rates of geopolymer concrete and chloride content. A correlation model for the corrosion rates of FC and GPC was also developed. The findings of the current research and the model developed are novel and contribute to the knowledge of long term degradation science of geopolymers and form concrete materials. Furthermore, the findings and methodology of the current research have practical significance in the construction and repair industry for determining the remaining service life for any reinforced and steel infrastructure.
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San Miguel, G. F., M. R. Alvarado, P. V. Tamez, R. G. Alcorta, R. M. Garza, and J. P. Farias. "Deterioro por corrosión de elementos de concreto armado de un edificio industrial." Revista ALCONPAT 2, no. 3 (September 30, 2012): 195–210. http://dx.doi.org/10.21041/ra.v2i3.38.
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RESUMENLa corrosión de las estructuras de concreto armado se acentúa cuando son colocadas en ambientes con microclimas extremadamente agresivos. La habilidad para evaluar la corrosión de las varillas de refuerzo en estas estructuras y poder estimar la vida en servicio remanente es tema de estudios en muchas partes del mundo. Este trabajo muestra la importancia de implementar una metodología de inspección y diagnóstico que genere, a través del empleo de equipos especializados y tecnología de punta, datos confiables que permitan el desarrollo de procesos de planeación en las intervenciones de rehabilitación y/o mantenimiento de los elementos de concreto reforzado. El conjunto de resultados permitió la optimización de recursos humanos y materiales del usuario final.Palabras Clave: Corrosión; concreto armado; evaluación; reparación.ABSTRACTCorrosion of reinforced concrete structures (RCS) is accentuated when there are placed in environments with extremely aggressive microclimates. In many parts of the world, the ability to evaluate the corrosion of rebars in these RCS and estimate the remaining service life is subject of study. This work shows that the implementation of an inspection and diagnosis methodology must generate reliable data, through the use of specialized equipment and technology. Additionally, the development of planning processes in rehabilitation interventions and/or maintenance of reinforced concrete elements should be privileged. The results obtained allowed the optimization of human and material resources of the end user.Keywords: Corrosion; reinforced concrete; evaluation; rehabilitation.
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Moon, Kyung Man, Sung Yul Lee, Jae Hyun Jeong, and Myeong Hoon Lee. "Coating Thickness of Reinforced Concrete Affecting to Cathodic Polarization and Cyclic Voltammogram of Reinforced Steel." Key Engineering Materials 723 (December 2016): 741–47. http://dx.doi.org/10.4028/www.scientific.net/kem.723.741.
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The reinforced concretes are often exposed to severely corrosive environments such as sea water, contaminated water, acid rain and seashore etc.. Therefore, the reinforced steel bar embedded in the concrete is increasingly corroded in various environments mentioned above, and this corrosion problem is thought to be very important in terms of the safety and economic points of view. In this study, a multiple mortar test specimen(W/C:0.5) with variation of coating thickness was prepared and immerged in flowing seawater for five years. And, the effects of coating thickness affecting to cathodic polarization and cyclic voltammogram were investigated using electrochemical methods. The thinner coating thickness, both invasion and diffusion of dissolved oxygen, water and chloride ion on the surface of reinforced steel bar is more easily compared to the thicker coating thickness. Thus, at the beginning of immersion, the rate of corrosion in the case of the thinner coating thickness is higher than that of the thicker coating thickness. However, it is considered that corrosion products deposited on the surface due to higher corrosion rate played the role as a resistance polarization, and increased the diffusion layer, as a result, decreased the corrosion current density compared to the thicker coating thickness. Consequently, the relationship between corrosion current density and the coating thickness were not well in good agreement with each other due to the corrosion products after being immersed for 5 years. Therefore, in order to more optimum evaluate for corrosion possibility of the reinforced steel embedded in the concrete, not only corrosion potential but also other parameters such as coating thickness, W/C ratio, and other corrosion environment should be investigated in the case of immersed in seawater for long years.
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Potapov, Yuri B., Sergey A. Pinaev, Arutyun A. Arakelyan, and Andrei D. Barabash. "Polymer-Cement Material for Corrosion Protection of Reinforced Concrete Elements." Materials Science Forum 871 (September 2016): 104–9. http://dx.doi.org/10.4028/www.scientific.net/msf.871.104.
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The paper presents composition of innovative material used for corrosion protection of reinforced concrete structures and experimental data on the increase in cracking of reinforced concrete elements coated with polymer-cement protective layer against corrosive media.
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Choe, Gyeongcheol, Yasuji Shinohara, Gyuyong Kim, Sangkyu Lee, Euibae Lee, and Jeongsoo Nam. "Concrete Corrosion Cracking and Transverse Bar Strain Behavior in a Reinforced Concrete Column under Simulated Marine Conditions." Applied Sciences 10, no. 5 (March 5, 2020): 1794. http://dx.doi.org/10.3390/app10051794.
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This study performed accelerated corrosion tests on reinforced concrete (RC) specimens reinforced with transverse steel bars to evaluate the concrete cracking and rebar strain behaviors caused by rebar corrosion. Seven RC specimens were created with variable compressive strengths, rebar diameters, and concrete cover thicknesses. To mimic in-situ conditions, the accelerated corrosion tests applied a current to the longitudinal bar and transverse bar for different periods of time to create an unbalanced chloride ion distribution. These tests evaluated the amount of rebar corrosion, corrosion cracking properties, and transverse bar strain behavior. The corrosion rate of the transverse bar was faster than that of the longitudinal bar, and cracking first occurred in the concreate around the transverse bar in the specimens with low concrete compressive strength and thin concrete cover. Corrosion cracking and rebar strain were greatly affected by the behavior of the corrosion products that resulted from the pore volume and cracking properties of the cement paste.
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Troconis de Rincón, O., M. Sánchez, V. Millano, J. Bravo, and S. Delgado. "Enseñanzas de casos de inspección en sótanos." Revista ALCONPAT 2, no. 2 (May 30, 2012): 104–13. http://dx.doi.org/10.21041/ra.v2i2.31.
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RESUMENEste trabajo muestra las enseñanzas obtenidas al evaluar y diagnosticar problemas por corrosión y estructurales en varios sótanos de diferentes tipos de edificaciones, ubicadas cerca y lejos de la costa. En este se reportan los resultados obtenidos de esta inspección, de los cuales se encuentran: levantamiento de daños, ensayos físico-químicos, mecánicos y electroquímicos que permitieron caracterizar el concreto y los daños por corrosión que puedan comprometer a las estructuras evaluadas. Dado que en la mayoría de los casos los sótanos se utilizan como estacionamientos, los problemas de corrosión se deben, en general, a la carbonatación del concreto. No obstante, este efecto se potenció por niveles freáticos altos y presencia de bolsas de agua salina ubicadas en el subsuelo del sótano, lo cual permitió no solo el ingreso del agua sino también de los iones cloruros hacia el concreto. En este trabajo se muestra la evaluación, así como las recomendaciones de las acciones a tomar para extender su vida en servicio.Palabras Clave: Corrosión; sótanos; concreto armado; evaluación; rehabilitaciónABSTRACTThis paper shows the lessons learned in evaluating and diagnosing corrosion and structural problems in several basements of different types of buildings located near and far from the coast. The results of this inspection are reported. They include: damage survey, physical-chemical, mechanical and electrochemical tests; all of which allowed characterizing the concrete and corrosion damages that could compromise the structures evaluated. Since in most cases the basements are used as parking lots, corrosion problems are due, in general, to the carbonation of concrete. However, this effect is potentiated by high freatic levels and the presence of saline water bags located in the subsoil of the basement, which allowed not only the ingress of water but also of chloride ions into concrete. This paper shows the evaluation and recommendations of actions to be taken to extend the service life of the reinforced concrete structures evaluated.Keywords: Corrosion; basements; reinforced concrete; evaluation; rehabilitation.
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Shukla, Divyansh, Abhay Kumar Jha, and Barun Kumar. "Experimental Study on the Effects of Corrosion in Reinforced Concrete Incorporating Steel Fiber and Ultra-Fine Slag." International Journal for Research in Applied Science and Engineering Technology 11, no. 4 (April 30, 2023): 2318–21. http://dx.doi.org/10.22214/ijraset.2023.50636.
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Abstract: In this work, a thorough review of the literature was conducted with a primary focus on accelerated corrosion-induced corrosion. The report that follows compares different reinforced concrete mixtures following corrosion. By adjusting the transparent cover and reinforcement diameter, a simple reinforced concrete specimen, a specimen of reinforced concrete mixed with steel fiber, and a specimen of reinforced concrete mixed with steel fibre and ultra-fine slag were all produced. Using the accelerated corrosion method, the rate of induced corrosion, the flexural strength before and after corrosion, and the depth of corrosion penetration were compared.
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Melchers, Robert E., and Henry Humphrey. "Concrete Alkali–Aggregate-Reactivity-Induced Steel Reinforcement Corrosion." Corrosion and Materials Degradation 4, no. 3 (July 21, 2023): 428–44. http://dx.doi.org/10.3390/cmd4030022.
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The alkali–aggregate reactivity (AAR) of concrete, long known for mass concrete, can also induce corrosion of steel in reinforced concrete structures. Several examples are given for which the origin of observed reinforcement corrosion and loss of concrete cover originally was attributed to chloride-induced or to carbonation-induced reinforcement corrosion. Critical reviews of these cases, using available information, suggest that, more likely, the observed crack patterns and concrete deterioration are the result of long-term AAR-induced concrete matrix expansion and loss of concrete strength and that these effects occurred prior to the eventual initiation of reinforcement corrosion. This proposition is supported by finite element and other stress analyses of various concrete–steel ensembles. They show that concrete expansion produces tensile stresses localised at and near exterior concrete surfaces or relative to the reinforcement. The locations of high-stress and -strain zones so produced correlate with field observations of long-term concrete cracking and delamination. The present interpretations highlight that AAR may be a significant contributor to initiation and subsequent long-term development of reinforcement corrosion in structurally reinforced concretes.
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Yang, Li Ming, Hong Fa Yu, and Hai Yan Ma. "Stress Corrosion of High Performance Hybrid Fibers Reinforced Expansive Concrete Exposed to Magnesium Sulfate Solution." Advanced Materials Research 79-82 (August 2009): 115–18. http://dx.doi.org/10.4028/www.scientific.net/amr.79-82.115.
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Deterioration of fly ash concrete (FAC), high performance concrete (HPC), and high performance hybrid fibers reinforced expansive concrete (HPHFREC) subjected to combined action of flexural load and 5% magnesium sulfate solution is investigated. The change of dynamic modulus of elasticity (DME) was monitored and recorded as to observe the corrosion of concrete specimens in magnesium sulfate environment. Results show that in the initial exposure stage, the relative dynamic modulus of elasticity (RDME) of concretes increase steadily as a result of the reinforced effect of flexural load and nucleation of attack products, consequently the microstructure is compacted and the strength of the concretes is enhanced in some extent. As for the later corrosion proceed, the interior cracks occurred and the flexural load accelerated the degradation of concrete. HPC demonstrated good corrosion resistance when it was exposed to only magnesium sulfate solution, and HPHFREC showed the best stress corrosion resistance when it was subjected to combined action of magnesium sulfate solution and flexural load.
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Song, Liu Bin, Dao Wu Yang, Zhong Liang Xiao, and Feng Zhang. "Research on Effects of Inhibitors on Anti-Corrosion Performance of Reinforced Bar in the Concrete." Advanced Materials Research 239-242 (May 2011): 1195–98. http://dx.doi.org/10.4028/www.scientific.net/amr.239-242.1195.
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The corrosion behavior of reinforcing bars in concrete was studied by simulating the 4×4 wire-beam electrode array. Different inhibitors were added to reinforced concrete. By measuring the open-circuit potential of an iron wire, the impact of different inhibitors on the corrosion of rebar in the concretes was studied after immersion in NaCl solution. The result showed that best protection was achieved by adding NaNO2 and aniline as inhibitors jointly to the concrete, as this combination maintained the open-circuit potential within the passivation range at all times, so ensuring the integrity of the passive membrane. By addition of this combination of the inhibitors, the compactibility of the cement concrete structure can be increased, thereby protecting the reinforcing bar against the external corrosive media.
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Guo, Xiao, Hongwei Wang, Kaizhong Xie, Tuo Shi, and Dan Yu. "Experimental and Numerical Study on the Influence of Corrosion Rate and Shear Span Ratio on Reinforced Concrete Beam." Advances in Materials Science and Engineering 2020 (September 8, 2020): 1–10. http://dx.doi.org/10.1155/2020/4718960.
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In order to study the influence of corrosion rate and shear span ratio on reinforced concrete beam, a numerical analysis method of corroded reinforced concrete beam was put forward. Bond-slip relationship formula between reinforcement and concrete was suggested. A three-dimensional finite element model of corroded reinforced concrete beam was established. Calculation method of ultimate bearing capacity for reinforced concrete beam was suggested. Ultimate bearing capacity experiment on 14 corroded reinforced concrete beams with different corrosion rates and shear span ratios was carried out. Numerical analysis results and experimental results were compared and analyzed. The results show that, for reinforced concrete beams with different corrosion rates and shear span ratios, load-deflection curve can be divided into elasticity stage and plasticity stage. With the increase of corrosion rate and shear span ratio, ultimate bearing capacity of corroded reinforced concrete beam decreased. When shear span ratio was 3.0, if corrosion rate increased by 1%, experimental value of ultimate bearing capacity decreased by 1.002 kN. When shear span ratio was 2.4, if corrosion rate increased by 1%, experimental value of ultimate bearing capacity decreased by 1.849 kN. The numerical analysis method put forward in this paper was feasible, and the suggested ultimate bearing capacity calculation method for reinforced concrete beam has a high accuracy.
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Raczkiewicz, Wioletta, Magdalena Bacharz, Kamil Bacharz, and Michał Teodorczyk. "Reinforcement Corrosion Testing in Concrete and Fiber Reinforced Concrete Specimens Exposed to Aggressive External Factors." Materials 16, no. 3 (January 30, 2023): 1174. http://dx.doi.org/10.3390/ma16031174.
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One of the leading causes of reinforced concrete degradation is chloride attack. It occurs due to the penetration of chlorides through pores and cracks into the concrete cover. This phenomenon becomes more dangerous if reinforced concrete elements are subjected to cyclic temperature changes. The concrete cover protects against corrosion. This paper presents research, the primary purpose of which was to determine the effect of the addition of steel fibers to concrete on the development of corrosion of the main reinforcement. The tests were carried out on three types of reinforced concrete specimens made of ordinary concrete and concrete with different amounts of steel fibers (0.25% and 0.50%). In order to initiate corrosion processes, specimens were partially submerged in a 3% sodium chloride solution and were subjected to freeze–thaw cycles. The electrochemical polarization galvanostatic pulse method was used for analyzing the reinforcement corrosion activity. Moreover, it was verified whether the corrosion of reinforced concrete elements affects the acoustic emission wave velocity. The addition of steel micro-reinforcement fibers increases the corrosion resistance of reinforced concrete. In addition, a strong linear correlation between the AE wave velocity and the values of the corrosion current density was revealed.
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Qiang, Yue, Li Li, and Ze Ping He. "Experiment Research on the Steel Fiber Reinforced Concrete in the Acid Environment." Advanced Materials Research 224 (April 2011): 224–28. http://dx.doi.org/10.4028/www.scientific.net/amr.224.224.
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For the purpose of studying the resistance of steel fiber reinforced concrete against the corrosion of different acid, test compressive strength and flexural strength of the steel fiber reinforced concrete of different volume rate after the corrosion of organic and inorganic acid, and express experiment results with the form of comprehensive corrosion coefficient and the flexural corrosion coefficient in order to reflect the corrosion degree. The results shows that, the organic corrosion has a stronger corrosion effect on the steel fiber reinforced concrete than the inorganic acid under the environment of same PH value. When steel fiber volume rate is 1.5%, the corrosion resistance capacity of the steel fiber reinforced concrete is best.
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Hameed, Asif, Muhammad Faheem Ud Din Afzal, Ali Javed, Ali Murtaza Rasool, Mohsin Usman Qureshi, Armin B. Mehrabi, and Imran Ashraf. "Behavior and Performance of Reinforced Concrete Columns Subjected to Accelerated Corrosion." Metals 13, no. 5 (May 10, 2023): 930. http://dx.doi.org/10.3390/met13050930.
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Steel reinforcement corrosion in concrete structures such as bridges, industrial plants, marine structures, and coastal buildings is a growing concern due to its impact on cost, safety, and serviceability. Corrosion leads to spalling, cracking, and reduced reinforcement diameter, which can compromise structural integrity. This study examines the behavior of concrete columns with corroded reinforcement in two phases. In the first phase, 72 columns of 150 × 150 mm cross-sectional dimensions and 300 mm length were cast and subjected to an accelerated corrosion technique. The study examined variables such as concrete cover, concrete strength, and corrosion exposure. The second phase involved studying the axial behavior of corroded columns concerning the effect of column length. Column specimens of 150 × 150 mm cross-sectional dimensions and lengths of 500 mm, 700 mm, and 900 mm were cast, corroded, and tested under axial compressive load. The study revealed that a 30 mm concrete cover offers 10% more protection against corrosion than a 20 mm cover. Continuous exposure to a corrosive environment reduces the load-carrying capacity by 50%, while columns with 28 MPa concrete strength can carry 4% more load. Longer columns are more susceptible to corrosion, leading to a significant reduction in load-carrying capacity and concrete cover damage. Therefore, maintaining adequate concrete cover, strength, and regular inspections are essential to address steel reinforcement corrosion and preserve structural integrity.
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Zheng, Zhupeng, Ying Lei, and Xin Xue. "Numerical Simulation of Monitoring Corrosion in Reinforced Concrete Based on Ultrasonic Guided Waves." Scientific World Journal 2014 (2014): 1–9. http://dx.doi.org/10.1155/2014/752494.
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Numerical simulation based on finite element method is conducted to predict the location of pitting corrosion in reinforced concrete. Simulation results show that it is feasible to predict corrosion monitoring based on ultrasonic guided wave in reinforced concrete, and wavelet analysis can be used for the extremely weak signal of guided waves due to energy leaking into concrete. The characteristic of time-frequency localization of wavelet transform is adopted in the corrosion monitoring of reinforced concrete. Guided waves can be successfully used to identify corrosion defects in reinforced concrete with the analysis of suitable wavelet-based function and its scale.
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Wang, Jun, Qiuyue Wang, Yun Zhao, Pengfei Li, Tongyuan Ji, Gongnian Zou, Yanxin Qiao, Zhou Zhou, Guowei Wang, and Dan Song. "Research Progress of Macrocell Corrosion of Steel Rebar in Concrete." Coatings 13, no. 5 (April 30, 2023): 853. http://dx.doi.org/10.3390/coatings13050853.
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Macrocell corrosion of steel rebar in concrete induced by corrosive environments has attracted widespread attention in the engineering community due to its rapid corrosion rate, diverse forms, and multiple incentives. Potential differences between dissimilar coupled rebar or different parts of the same rebar mainly cause macrocell corrosion of steel rebar. The more significant the potential difference, the faster the corrosion rate of the macrocell. Based on the existing research reports on macrocell corrosion of reinforced concrete, this review paper comprehensively discusses the macro- and micro-corrosion behavior of various types of steel rebar, and a variety of induction factors, such as dissimilar metals and concentration differences of the service environment, development rules. and electrochemical mechanisms for corrosion of rebar macrocells are summarized. ZRA (zero-resistance ammeter), micro-area electrochemical testing technology and evaluation techniques commonly used in the laboratory, and electrochemical testing techniques used in engineering testing are listed. Common experimental models for corrosion of rebar macrocells are briefly introduced. Based on the internal characteristics of macrocell corrosion of reinforced concrete, this paper further proposes the control strategy of macrocell corrosion, starting from the improvement of the corrosion resistance of the rebar and regulating the service environment of the reinforced concrete structure (RCS). Meanwhile, the future direction of macrocell corrosion of steel rebar is also preliminarily prospected.
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Kolchunov, Vitaly, Natalia Androsova, and Tatyana Kolchina. "Crack Resistance Criteria for Reinforced Concrete Beams with Corrosion Damage in Strength Resource Assessment." Applied Mechanics and Materials 725-726 (January 2015): 740–45. http://dx.doi.org/10.4028/www.scientific.net/amm.725-726.740.
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In the framework of ultimate state calculation methods the paper presents some propositions for stress-strain state, crack resistance analysis and failure state of reinforced concrete structures with corrosion damage at supports. The work concerns the durability of concrete and reinforced concrete elements with corrosion damage. The theory for reinforced concrete with corrosion damage is presented for plane stress state
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Wang, Qianying, Jigang Zhang, Mingchao Shan, Bingying Yu, Yang Zhao, and Ran Yang. "Experimental Study on the Effect of Boric Acid Corrosion on the Performance of Reinforced Concrete." Advances in Materials Science and Engineering 2021 (June 18, 2021): 1–13. http://dx.doi.org/10.1155/2021/5534917.
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In this study, the effect of boric acid in the cooling water system of nuclear power plants on the durability of reinforced concrete was experimentally studied. The mechanical properties of reinforced concrete under boric acid solution environments were studied by accelerated test methods. In addition, the effect of boric acid on the electrochemical behavior of steel bar and microstructure of concrete was studied. The results showed that boric acid corrosion does not affect reinforced concrete to a large extent, as corrosion only occurs on the surface of reinforced concrete, and thus, the internal reinforced concrete still maintains a high alkaline environment. At a boric acid concentration of 3%, corrosion products are crystallized on the surface of the specimen, which inhibits further corrosion.
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Lin, Yue Zhong. "On the Load of Reinforced Concrete Column by Seawater Corrosion." Advanced Materials Research 368-373 (October 2011): 975–78. http://dx.doi.org/10.4028/www.scientific.net/amr.368-373.975.
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The reinforced concrete construction of port, wharf, inshore platform etc, which expose in the bad environment, can suffer influence of the corrosion and lower its safety. Particularly with the seawater corrosion, the reinforced concrete construction will suffer to break easily and result a bigness of loss. Therefore, the construction's safe and dependable increasingly become the important problem that study by people. The paper tested the load about 15 experiment columns of reinforced concrete, which are eroded in the artificial seawater corrosion, studied the load changing of reinforced concrete column which in different times of suffering decay. It afforded the basis for analysis the load of reinforced concrete construction in the corrosion environment.
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Zhang, Zhiqiang, Ruikai Gong, Heng Zhang, and Wanping He. "The Sustainability Performance of Reinforced Concrete Structures in Tunnel Lining Induced by Long-Term Coastal Environment." Sustainability 12, no. 10 (May 12, 2020): 3946. http://dx.doi.org/10.3390/su12103946.
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At present, the damage caused by steel corrosion to structures has become a serious problem all over the world. In order to study the mechanical behaviors of tunnel lining structure system under the corrosive environment to rebars, first, the bending tests were performed to investigate the crack propagation behavior and structural bearing capacity of the reinforced concrete bending members degraded by corrosion. Secondly, the pull-out tests were performed to investigate the degradation of bonding strength between corroded rebars and the concrete. Finally, on the basis of the findings from the pull-out tests, a 3-D finite element bond-slip model of reinforced concrete lining structure has been established to simulate the changes of bearing capacity and durability of tunnel reinforced concrete lining under different corrosion degrees. The research has revealed: Rebar corrosion is the most important factor affecting concrete and steel corrosion. As the conversion rust rate increases, the ultimate drawing force continues to decrease. With the increase of the corrosion rate, the deflection of the specimen when it is destroyed becomes smaller, the cracking load becomes smaller and the bearing capacity also decreases. As the degree of corrosion increases, the overall deformation of the tunnel increases, and the overall safety of the lining structure decreases. The corner position is the most prone to problems after the lining structure is corroded, so pay more attention. As well, the safety of the lining structure will be basically lost when the final corrosion rate of the steel bars is greater than 30%. The findings of this research can be used to evaluate the corrosion degree of tunnel reinforced concrete lining structure and support the durability design of new tunnel concrete lining structure.
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Sun, Li, Zeyu Yang, Qiao Jin, and Weidong Yan. "Effect of Axial Compression Ratio on Seismic Behavior of GFRP Reinforced Concrete Columns." International Journal of Structural Stability and Dynamics 20, no. 06 (May 30, 2020): 2040004. http://dx.doi.org/10.1142/s0219455420400040.
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Traditional reinforced concrete columns have demonstrated poor seismic performance especially in corrosive environment as the reinforcement bars experience severe corrosion under such conditions. To overcome the problem of steel corrosion, glass fiber-reinforced polymer (GFRP) reinforced concrete columns have gained significant attention in recent years. However, the seismic performance of GFRP reinforced concrete column is not well understood yet. One of the main challenges associated with the use of GFRP bars is its brittle behavior. Therefore, it is necessary to investigate the mechanical properties and failure modes of GFRP reinforced concrete structures under seismic action. In this research, the seismic behavior of GFRP reinforced concrete columns and conventional columns under different axial compression ratios are analyzed by low-cycle repeated pseudo-static loading tests. As a result, the deformation and the seismic energy dissipation capacity of GFRP reinforced concrete columns are investigated and discussed. Furthermore, the failure mechanism of GFRP bar structure is studied to provide the basis for improving the seismic design method of GFRP reinforced concrete structure and modifying the code for seismic design. In addition, the influence of axial compression ratio on the seismic behavior of full GFRP reinforced concrete columns is investigated. The results of this experiment demonstrate that with the increase of axial compression ratio, the ultimate bearing capacity of GFRP reinforced concrete columns increases, while the deformation and the cumulative energy dissipation capacity decrease.
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Smolyago, G. A., A. V. Dronov, and N. V. Frolov. "MODELING OF REDUCTION IN THE CROSS-SECTIONAL AREA OF STEEL REINFORCEMENT IN CONCRETE UNDER THE ACTION OF CORROSIVE ENVIRONMENT." Proceedings of the Southwest State University 21, no. 1 (February 28, 2017): 43–49. http://dx.doi.org/10.21869/2223-1560-2017-21-1-43-49.
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Process of depassivation of steel in concrete under the action of chloride corrosive environment is considered. Method of durable testing of bended reinforced concrete structures during corrosive period is described. Results of experimental research in steel reinforcement corrosion in reinforced concrete beams under the action of corrosive environment are described in the article. The diagram of corrosive potential changes during the testing time is given in the article. Measurements of corrosion potential were carried out by the corrosion analyzing instrument. Analysis of corrosive potential changes during the testing time was carried out. Main properties and features of chloride corrosion process and damages are considered. Corrosive pits on the surface of the reinforcement bars were studied. Measurements of depth and diameter of the corrosive pits were carried out. Stress-strain diagrams of steel after the corrosive period were obtained. Mathematical model of reduction in the cross-sectional area of steel reinforcement in concrete under the action of corrosive chloride environment is suggested. This model allows to consider effect of concrete cover thickness on depth of corrosion. Comparison of experimental results and theoretical calculations reveals high accuracy of corrosion damage definition by given mathematical model. The ways to use the model are suggested. The given model allows to consider corrosive damages of steel rebars by definition of cross-section area losses and may be used in calculations of strength and deformations of RC structures. It’s possible to use the model for prediction of the remaining strength life of RC structures.
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Zhou, Qun, Zhong He Shui, Yi De Xiao, and Chang Sheng Xu. "Effects of Coating/Electroplating on Corrosion Resistance of Steel Bar in Reinforced Concrete." Advanced Materials Research 446-449 (January 2012): 3176–79. http://dx.doi.org/10.4028/www.scientific.net/amr.446-449.3176.
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One of the main reasons for the damage of reinforced concrete is the expansion caused by corrosion of steel bar in concrete. In this paper, the equivalent circuit that inflects corrosion process of steel bars in reinforced concrete was analyzed, with the A.C.Impedance Spectrum method. And the effects of surface treatment of the bars on corrosion resistance of the reinforced concrete were investigated. Study results show that the surface coating (plating) on the built-in reinforcement can effectively prevent corrosion of steel bar, thereby enhancing the durability of concrete structures.
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Ma, Zhiming, Tiejun Zhao, Jianzhuang Xiao, and Ting Guan. "Evaluation of rebar corrosion in reinforced concrete under freeze-thaw environment and protection measures." Anti-Corrosion Methods and Materials 63, no. 2 (March 7, 2016): 128–36. http://dx.doi.org/10.1108/acmm-11-2014-1461.
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Purpose – Rebar corrosion in reinforced concrete is the major reason for the durability degradation, especially under harsh environment. This paper presents an experiment conducted to investigate the influence of freeze-thaw cycles on the rebar corrosion in reinforced concrete. The purpose of this paper is to provide fundamental information about rebar corrosion under frost environment and improvement measures. Design/methodology/approach – The related elastic modulus and compressive strength of different concrete specimens were measured after different freeze-thaw cycles. The accelerated rebar corrosion test was carried out after different freeze-thaw cycles; additionally, the value of calomel half-cell potential was determined. The actual rebar corrosion appearance was checked to prove the accuracy of the results of calomel half-cell potential. Findings – The results show that frost damage aggravates the rebar corrosion rate and degree under freeze-thaw environment; furthermore, the results become more obvious with the freeze-thaw cycles increasing. Mixing the air-entrained agent into fresh concrete to prepare air-entrained concrete, increasing the cover thickness and processing the surface of concrete with a waterproofing agent can significantly improve the resistance to rebar corrosion. From the actual appearance of rebar corrosion, the results of calomel half-cell potential can well reflect the actual rebar corrosion in reinforced concrete. Originality/value – The durability of reinforced concrete is mainly determined on chloride penetration that brings about rebar corrosion in chloride environments. Furthermore, the degradation of concrete durability becomes more serious in the harsh environment. As the concrete exposure to the freeze-thaw cycles environment, the freeze-thaw cycles accelerate the concrete damage, and the penetration of chloride into the concrete becomes easier because of the growing pore and crack sizes. In addition, rebar corrosion caused by chloride is one of the major forms of environmental attack on reinforced concrete. The tests conducted in this paper will describe the rebar corrosion in reinforced concrete under freeze-thaw environment.
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Zhang, Xuhui, Xun Wu, and Yang Wang. "Corrosion-Effected Bond Behavior between PVA-Fiber-Reinforced Concrete and Steel Rebar under Chloride Environment." Materials 16, no. 7 (March 27, 2023): 2666. http://dx.doi.org/10.3390/ma16072666.
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Corrosion-effected bond behavior between polyvinyl-alcohol-fiber-reinforced concrete and steel rebar under a chloride environment is the experimental subject studied in the present work. Twenty-four pull-out specimens are designed and subjected firstly to an accelerated corrosion test. The effects of polyvinyl alcohol fibers on the cracking behavior, chloride penetration of concrete members and the corrosion loss of steel rebars during the corrosion test are discussed. After this, these corroded specimens are subjected to a pull-out test. The failure mode, the bond-slip curves and the typical bond-stress values are measured during the test. The effects of polyvinyl alcohol fibers and corrosion loss on bond behavior between polyvinyl-alcohol-fiber-reinforced concrete and steel rebar are clarified. Results show that the polyvinyl-alcohol-fiber-reinforced concrete exhibits worse resistance to corrosion damage than plain concrete. The cracking width, chloride penetration depth in concrete and the corrosion loss of steel rebar are more serious for the specimens with more polyvinyl alcohol fibers. The polyvinyl alcohol fibers also negatively affect bonding in ascending branches for both the specimens, but improve the bonding in descending branches after peak stress in the case of splitting. In the present test, the bond strength of corrosive specimens is increased slightly and then decreases gradually with the deepening of corrosion loss. The failures of specimens change from pull-out to splitting-pull-out as the corrosion time exceeds 30 days. Compared with uncorroded specimens, the maximum degradation of bond strength is about 50.1% when the corrosion is increased from 0% to 15%.
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Zhu, Fangzhi, Zhiming Ma, and Tiejun Zhao. "Influence of Freeze-Thaw Damage on the Steel Corrosion and Bond-Slip Behavior in the Reinforced Concrete." Advances in Materials Science and Engineering 2016 (2016): 1–12. http://dx.doi.org/10.1155/2016/9710678.
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This paper mainly studies the behavior of steel corrosion in various reinforced concrete under freeze-thaw environment. The influence of thickness of concrete cover is also discussed. Additionally, the bond-slip behavior of the reinforced concrete after suffering the freeze-thaw damage and steel corrosion has also be presented. The results show that the freeze-thaw damage aggravates the steel corrosion in concrete, and the results become more obvious in the concrete after suffering serious freeze-thaw damage. Compared with the ordinary concrete, both air entrained concrete and waterproofing concrete possess better resistance to steel corrosion under the same freeze-thaw environment. Moreover, increasing the thicknesses of concrete cover is also an effective method of improving the resistance to steel corrosion. The bond-slip behavior of reinforced concrete with corroded steel decreases with the increase of freeze-thaw damage, especially for the concrete that suffered high freeze-thaw cycles. Moreover, there exists a good correlation between the parameters of bond-slip and freeze-thaw cycles. The steel corrosion and bond-slip behavior of reinforced concrete should be considered serious under freeze-thaw cycles environment, which significantly impact the durability and safety of concrete structure.
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Zhang, Liye, Limin Sun, and Lijuan Dong. "Experimental Study on the Relationship between the Natural Frequency and the Corrosion in Reinforced Concrete Beams." Advances in Materials Science and Engineering 2021 (July 22, 2021): 1–10. http://dx.doi.org/10.1155/2021/9976738.
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Due to many nondamage factors such as temperature, humidity, carbonation, and corrosion effects on natural frequency, the key problem of the application frequency-based method to detect damage is to reveal the rules of these factors affect natural frequency and further to eliminate their effects. The long-term characteristics of reinforced concrete structures require a lot of attention, especially in corrosive environment. In this paper, an experimental investigation was conducted to study the deflection and natural frequency of reinforced concrete beam in a marine environmental chamber for six corrosion stages (accelerated corrosion for 0, 20, 40, 70, 100, and 140 days). The experimental results demonstrated that deflection increases with corrosion time, while natural frequency decreases with corrosion time. Based on the accelerate corrosion test data of reinforced concrete beams, the general expression of the relationship between corrosion depth and natural frequency has been established through the fitting curve method. The polynomial model has been selected for establishing the relationship between steel corrosion depth (including the main reinforcement and stirrup) and natural frequency. The reason for selecting the polynomial model is that the sum of squares due to error (SSE) is closer to 0 and the coefficient of multiple determination (R-square) is closer to 1. This investigations help to discriminate the cause of reinforced concrete beams natural frequency change, to eliminate nondamage factors affects, and to apply many structural damage identification methods effectively.
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Liu, Xiao Chun, Jun Wei, and Zhen Yu Wang. "Use of Vibrating Wire Strain Gauges to Monitor Corrosion-Induced Deterioration of Concrete." Key Engineering Materials 517 (June 2012): 357–62. http://dx.doi.org/10.4028/www.scientific.net/kem.517.357.
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Steel reinforcement corrosion is always one of the most significant incentives of concrete structure deterioration, especially under severe chloride erosion environment. In order to describe the whole process of concrete deterioration induced by reinforcement corrosion, the mechanism of rust expansion and crack propagation in concrete was analyzed from the perspective of elastoplastic mechanics and fracture mechanics firstly, and experimental study was carried out to use vibrating wire strain gauges for monitoring corrosion-induced concrete deterioration process. The mechanism analysis of corrosion-induced concrete deterioration indicates that the degradation process of cover concrete can be divided into aggressive medium transmission process, free corrosive expansion process, corrosive expansion stress development process, corrosive expansion crack generation and propagation process, and vibrating wire strain gauges can be used to monitor corrosion-induced cover concrete stress development, crack initiation and propagation process along with the procedure of reinforcement corrosion. The test curve seems to be generally consistent with that of the theoretic analysis, and the signals captured by vibrating wire strain gauges can successfully reflect the durability degradation process of reinforced concrete structure under severe erosion environment.
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Melchers, Robert E. "Long-Term Durability of Marine Reinforced Concrete Structures." Journal of Marine Science and Engineering 8, no. 4 (April 18, 2020): 290. http://dx.doi.org/10.3390/jmse8040290.
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The sustainability of reinforced concrete is critical, particularly for structures exposed to marine environments. Chlorides are implicated in causing or accelerating reinforcement corrosion and potentially earlier expensive repairs, yet there are many older reinforced concrete structures in good condition for many decades despite very high chloride levels at the reinforcement. The reasons for this are reviewed briefly, together with recent experimental work that better defines the role of chlorides. One is initiation of reinforcement corrosion but only through localized pitting at air-voids in concrete at the interface with the steel reinforcement. These tend to be small or negligible for high quality well-compacted concretes. The other role for chlorides has been shown, in experimental work, to accelerate the long-term loss of concrete alkali material. On the other hand, a review of practical experience shows that what has been termed chloride-induced reinforcement corrosion often is not that at all, but is the end-product of factors that impair the protective nature of the concrete. As reviewed herein, these include poor compaction, physical damage to concrete cover, concrete shrinkage, and alkali-aggregate reactions. The various observations presented are important for the proper understanding, analysis, and design of durable reinforced concrete structures exposed to chloride-rich environments.
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Nguyen, Wilson, Jacob F. Duncan, Paulo J. M. Monteiro, and Claudia P. Ostertag. "Multi-Scale Characterization of Corrosion Initiation of Preloaded Hybrid Fiber-Reinforced Concrete Composites." Key Engineering Materials 711 (September 2016): 195–202. http://dx.doi.org/10.4028/www.scientific.net/kem.711.195.
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Many reinforced concrete structures susceptible to corrosion damage are subjected to externally applied loads, causing cracking. These cracks increase the permeability of the material, accelerating the ingress of corrosion-inducing deleterious agents. In this paper, the effect of multiple microcracking and macrocrack formation on corrosion initiation was investigated. A hybrid fiber-reinforced concrete (HyFRC), which forms ductile, distributed microcracking prior to dominant crack localization due to multiple tiers of fiber reinforcement, is being studied for its performance against corrosion damage. The effect of matrix cracking on corrosion initiation was studied with beam specimens preloaded in flexure prior to long-term corrosion exposure. Reinforced HyFRC composites were found to have a delayed corrosion initiation response due to reductions in crack widths and suppression of splitting cracks, compared to conventional reinforced concrete. The influence of microcracks on corrosion is studied using X-ray micro-computed tomography (μCT) on reinforced fiber-reinforced cementitious composites and reinforced mortar preloaded in tension.
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Zhang, Wan You, Rui Yuan Zhang, and Lijuan Xi. "Corrosion of Reinforced Concrete in Accelerated Tests." Advanced Materials Research 610-613 (December 2012): 485–89. http://dx.doi.org/10.4028/www.scientific.net/amr.610-613.485.
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In order to study the correlation between accelerated corrosion and natural corrosion, reinforced surface morphology, steel potentials and corrosion quality were investigated by using full immersion and half immersion in this paper. The results showed that the effort of half immersion accelerated corrosion was similar to natural corrosion, and each of the tendencies of potential change was same, but the mechanisms of corrosion were different. The degree of steel corrosion, estimated by Faraday’s law, was slightly higher than the level of actual corrosion.
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Yang, Qiao, and Xiao E. Zhu. "A Study on Carbon Fiber Influence to Rebar Corrosion in Concrete." Applied Mechanics and Materials 204-208 (October 2012): 3114–18. http://dx.doi.org/10.4028/www.scientific.net/amm.204-208.3114.
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Rebar corrosion test of Carbon Fiber Reinforced Polymer (CFRP) concrete was did. Carbon fiber in concrete improved the compression strength of the concrete, but width and number of concrete cracks was not reduced, carbon fiber has not obvious act for improving concrete corrosion crack behavior. CFRP concrete Corrosion potential was a little high than common concrete, carbon fiber has not obvious act for improving concrete behavior in protecting steel beyond corrosion. The porosity of the carbon fiber reinforced polymer concrete was twice of the common concrete, carbon fiber added to concrete lead to increase porosity and maybe decrease concrete behavior in protecting the embedded steel in corrosion.
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Dekhterev, Denis, and Tatyana Matseevich. "Assessment of the reliability of bent reinforced concrete elements under corrosive effects." E3S Web of Conferences 410 (2023): 02029. http://dx.doi.org/10.1051/e3sconf/202341002029.
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The main problem of reducing the reliability and durability of reinforced concrete structures is the corrosion of concrete and reinforcement of operated buildings and structures. Calculation of structures made of reinforced concrete, taking into account environmental influences, is complicated by the stochastic nature of the parameters of corrosion processes. The conducted studies are aimed at solving the problem of improving the methodology of the probabilistic approach to the calculation of corrosion-damaged reinforced concrete elements. The article considers a probabilistic assessment of reliability for the most common bent reinforced concrete elements, taking into account corrosive wear and the time factor. The modeling of the effect of corrosion processes on the stress-strain state of a reinforced concrete element was carried out using the concrete deformation diagram, which takes into account the decrease in strength characteristics with an increase in the concentration of an aggressive medium in concrete. The scheme of propagation of an aggressive environment in concrete is adopted according to the diffuse front method. Corrosion processes in reinforcement were taken into account by reducing the effective cross-sectional area of reinforcing bars. The change in the properties of steel (its embrittlement) with an increase in the concentration of an aggressive medium was not taken into account. Reinforcement corrosion was simulated after the incubation period, after the concentration of the aggressive medium on the surface of the reinforcing bars reached a critical value. The determination of the moment of the onset of the limit state in the element was carried out on the basis of a nonlinear deformation model at each point of the section of the element to achieve the maximum possible tensile or compression strains in concrete and reinforcement. To solve the problem of reliability assessment, the method of statistical modeling implemented in a specialized software package was used. To apply this method, according to previous studies, the probabilistic parameters of all random variables were taken: mathematical expectation and standard deviation. Based on the results of the reliability assessment, graphs of the decrease in the reliability of a bent reinforced concrete element from the time of exposure to an aggressive environment were obtained.
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Zhou, Yingwu, Yaowei Zheng, Lili Sui, Biao Hu, and Xiaoxu Huang. "Study on the Flexural Performance of Hybrid-Reinforced Concrete Beams with a New Cathodic Protection System Subjected to Corrosion." Materials 13, no. 1 (January 5, 2020): 234. http://dx.doi.org/10.3390/ma13010234.
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Steel corrosion is considered as the main factor for the insufficient durability of concrete structures, especially in the marine environment. In this paper, to further inhibit steel corrosion in a high chloride environment and take advantage of the dual-functional carbon fiber reinforced polymer (CFRP), the impressed current cathodic protection (ICCP) technique was applied to the hybrid-reinforced concrete beam with internally embedded CFRP bars and steel fiber reinforced polymer composite bar (SFCB) as the anode material while the steel bar was compelled to the cathode. The effect of the new ICCP system on the flexural performance of the hybrid-reinforced concrete beam subjected to corrosion was verified experimentally. First, the electricity-accelerated precorrosion test was performed for the steel bar in the hybrid-reinforced beams with a target corrosion ratio of 5%. Then, the dry–wet cycles corrosion was conducted and the ICCP system was activated simultaneously for the hybrid-reinforced concrete beam for 180 days. Finally, the three-point bending experiment was carried out for the hybrid-reinforced concrete beams. The steel bars were taken out from the concrete to quantitatively measure the corrosion ratio after flexural tests. Results showed that the further corrosion of steel bars could be inhibited effectively by the ICCP treatment with the CFRP bar and the SFCB as the anode. Additionally, the ICCP system showed an obvious effect on the flexural behavior of the hybrid-reinforced concrete beams: The crack load and ultimate load, as well as the stiffness, were enhanced notably compared with the beam without ICCP treatment. Compared with the SFCB anode, the ICCP system with the CFRP bar as the anode material was more effective for the hybrid-reinforced concrete beam to prevent the steel corrosion.
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Soudki, Khaled A., and Ted G. Sherwood. "Behaviour of reinforced concrete beams strengthened with carbon fibre reinforced polymer laminates subjected to corrosion damage." Canadian Journal of Civil Engineering 27, no. 5 (October 1, 2000): 1005–10. http://dx.doi.org/10.1139/l00-052.
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The viability of carbon fibre reinforced polymer (CFRP) laminates for the strengthening of corrosion damaged reinforced concrete bridge girders is addressed in this paper. Ten reinforced concrete beams (100 × 150 × 1200 mm) with variable chloride levels (0-3%) were constructed. Six beams were strengthened by externally epoxy bonding CFRP laminates to the concrete surface. The tensile reinforcements of three unstrengthened and four strengthened specimens were subjected to accelerated corrosion by means of impressed current to 5, 10, and 15% mass loss. Strain gauges were placed on the CFRP laminates to monitor and quantify tensile strains induced by the corrosion process. Following the corrosion phase, the specimens were tested in flexure in a four-point bending regime. Test results revealed that CFRP laminates successfully confined the corrosion cracking, and the total expansion of the laminate exhibited an exponential increase throughout the corrosion process. All the strengthened beams exhibited increased stiffness over the unstrengthened specimens and marked increases in the yield and ultimate strength. The CFRP strengthening scheme was able to restore the capacity of corrosion damaged concrete beams up to 15% mass loss.Key words: CFRP laminates, corrosion, confinement, expansion, load tests, strengthening, bond strength, reinforced concrete.
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Ren, Zhao Jun. "Influence of Water Repellent Treatment on Corrosion of Steel in Concrete with Chloride Ingress." Advanced Materials Research 368-373 (October 2011): 2430–36. http://dx.doi.org/10.4028/www.scientific.net/amr.368-373.2430.
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Abstract. Corrosion of steel due to chloride ingress is a worldwide problem in reinforced concrete. In order to control such chloride-induced corrosion and evaluate the effectiveness of silane water repellent surface treatment on steel corrosion in concretes with different chloride ingress, two series of reinforced concrete specimens were used to investigate experimentally. In the first series, concrete was applied permanent migrating chloride from a reservoir of 3% NaCl solution which was placed on the top surface of each specimen. For comparison, the same concrete was made with silane water repellenet treatment correspondly. Tests were taken with half-cell potential and polarization resistance methods. Results show that steels in concrete without water repellent treatment have more negative half cell potential, higher mass loss ratio and bigger corrosion current density, and the effect of improvement through silane liquid surface treatment is evident. In the second series,concrete was same to the first one, but for wetting and drying cycle chloride ingress. Results indict that corrosion potentials decreased in negative little and later keep stable in the beginning period after water repellent treatment. Relatively for specimens without treatment, the value of corrosion negative corrosion potentials and corrosion current densities increase all the time.
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Hu, Chang-Shun, Shiping Yin, and Meng-Ti Yin. "Study on the interfacial bonding behaviour of corroded steel bars and TRC constrained concrete." Anti-Corrosion Methods and Materials 66, no. 5 (September 2, 2019): 661–70. http://dx.doi.org/10.1108/acmm-12-2018-2040.
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Purpose This paper aims to evaluate the bonding properties of textile reinforced concrete (TRC)-confined concrete and corroded plain round bars. Design/methodology/approach The bonding performance of three types of specimens (not reinforced, reinforced after corrosion and reinforced before corrosion) was studied by a central pull out test. Findings The ultimate bond strength between the corroded steel bars and the concrete is improved when the corrosion ratio is small. After cracking, the degree of corrosion continues to grow and the ultimate bond strength decreases. TRC reinforcement has no detectable effect on the interfacial bonding properties between concrete and plain round bars when the corrosion of steel bars is small; however, when the concrete cracks under the action of rust corrosion, the TRC constraints can effectively improve the bonding performance of the two components. Practical implications TRC layer significantly delayed the chloride penetration rate, which can effectively limit the development of corrosion cracking.
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Jeong, Jin A. "Experimental Study of Corrosion Sensors for the Design Technology of Bridge Longevity." Applied Mechanics and Materials 597 (July 2014): 421–24. http://dx.doi.org/10.4028/www.scientific.net/amm.597.421.
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Corrosion of steel reinforcement is a major factor in the deterioration of harbor and bridge structure. Steel corrosion in concrete must be checked for investigating the condition of a reinforced concrete structure. The several way how to measuring corrosion condition of reinforced concrete, but the corrosion potential measurement is a very simple, rapid, cost-effective and non-destructive technique to evaluate the severity of corrosion in reinforced concrete structure. However some particular situations may not relate to the reinforcement corrosion probability and a simple comparison of the corrosion potential data with the ASTM Standard on steel reinforcement corrosion probability could prove meaningless because of environment factors as oxygen concentration, chloride content, the concrete resistance. Therefore this paper proposed compact designed corrosion sensors to monitor several corrosion factors, and the electrochemical measurement and evaluation have been carried out to investigate rebar corrosion, and a reasonable prediction of corrosion has been obtained in terms of nondestructive electrochemical point of view.
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Constantinescu, Vasile, Gheorghe Veniamin Bogus, Rares George Taran, and Ioan Carcea. "New Composite Materials that Reduce the Effect of Reinforcement Corrosion." Advanced Materials Research 837 (November 2013): 265–70. http://dx.doi.org/10.4028/www.scientific.net/amr.837.265.
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Concrete is a complex material of construction that enables the high compressive strength of natural stone to be sed in any configuration. In tension, however, concrete can be no stronger than the bond between the cured cement and the surfaces of the aggregate. This is generally much lower than the compressive strength of the concrete. Concrete is therefore frequently reinforced, usually with steel. When a system of steel bars or a steel mesh is incorporated in the concrete structure in such a way that the steel can support most of the tensile stresses and leave the immediately surrounding concrete comparatively free of tensile stress, then the complex is known as reinforced concrete. Corrosion of reinforcing steel in concrete leads to the premature failure of many structures exposed to harsh environments. Rust products form on the bar, expanding its volume and creating stress in the surrounding concrete. This leads to cracking and spalling, both of which can severely reduce the service life and strength of a member. Corrosion of reinforcing steel in concrete structures is one of the most expensive problems facing civil engineers in the world. The structural integrity of many bridges, overpasses, parking garages, and other concrete structures has been impaired by corrosion, and repairs are urgently required to ensure public safety. Corrosion-induced deterioration of reinforced concrete can be modelled in terms of three component steps: (1) time for corrosion initiation; (2) time, subsequent to corrosion initiation, for appearance of a crack on the external concrete surface (crack propagation); and (3) time for surface cracks to progress into further damage and develop into spalls, to the point where the functional service life, is reached. The two most common causes of reinforcement corrosion are: (i) localized breakdown of the passive film on the steel by chloride ions and (ii) general breakdown of passivity by neutralization of the concrete, predominantly by reaction with atmospheric carbon dioxide. Sound concrete is an ideal environment for steel but the increased use of deicing salts and the increased concentration of carbon dioxide in modern environments principally due to industrial pollution, has resulted in corrosion of the rebar becoming the primary cause of failure of this material. The scale of this problem has reached alarming proportions in various parts of the world. Corrosion in reinforced concrete structures is causing deterioration of our infrastructure. Structures in or near marine environments and transportation structures on which deicing salts are used are especially vulnerable. A widely promoted method for repairing damaged structures or for protecting structures in corrosive environments is the application of fiber-reinforced composite wraps over the surface of the structures elements.
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Yang, Wei Jun, Hong Jia Huang, Wen Yu Jiang, and Yi Bin Peng. "Research on Shear Bearing Capacity of Reinforced Concrete Short Beam in Salt-Fog Environment." Advanced Materials Research 455-456 (January 2012): 1079–83. http://dx.doi.org/10.4028/www.scientific.net/amr.455-456.1079.
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Shantou atmospheric salt-fog environment is simulated with the comprehensive salt spray test chamber. By using reinforced concrete short beams under different water-cement radio, different corrosion time, the inclined section degradation rules of the corrosive reinforced concrete members are researched for establishing shear capacity of short beam formulas in salt-fog environment.
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Dubchynchyk, O. I. "THE INFLUENCE OF CORROSION OF CONCRETE AND REINFORCEMENT ON THE DURABILITY OF CONCRETE BRIDGE SPANS." Science and Transport Progress, no. 6 (March 25, 2005): 109–12. http://dx.doi.org/10.15802/stp2005/20387.
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The article examines the questions of the work of reinforced concrete span structures of railway bridges having damages in the form of corrosions of the concrete and armature and offers the dependencies for determination of the measure of damage accumulation in the process of corrosion of concrete and armature in time.