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Journal articles on the topic 'Corrosion of reinforcement'
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1
Hollý, Ivan, and Juraj Bilčík. "Effect of Chloride-Induced Steel Corrosion on Working Life of Concrete Structures." Solid State Phenomena 272 (February 2018): 226–31. http://dx.doi.org/10.4028/www.scientific.net/ssp.272.226.
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The reinforcing steel embedded in concrete is generally protected against corrosion by the high alkalinity (pH = 12.5 to 13.5) of the concrete pore solution. The structural degradation of concrete structures due to reinforcement’s corrosion has an impact on the safety, serviceability and durability of the structure. The corrosion of reinforcements in the construction of a transport infrastructure (especially bridges), parking areas, etc., is primarily initiated by chlorides from de-icing salts. When corrosion is initiated, active corrosion results in a volumetric expansion of the corrosion products around the reinforcing bars against the surrounding concrete. Reinforcement corrosion causes a volume increase due to the oxidation of metallic iron, which is mainly responsible for exerting the expansive radial pressure at the steel–concrete interface and development of hoop tensile stresses in the surrounding concrete. When this tensile stress exceeds the tensile strength of the concrete, cracks are generated. Higher corrosion rates can lead to the cracking and spalling of the concrete cover. Continued corrosion of reinforcement causes a reduction of total loss of bond between concrete and reinforcement.
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Sun, Qi Lei, Li Zhang, Jie Dong, and Lu Hua He. "Study on Electrochemical Behavior of Prestressed Reinforcement in Simulated Concrete Solution." Applied Mechanics and Materials 357-360 (August 2013): 917–20. http://dx.doi.org/10.4028/www.scientific.net/amm.357-360.917.
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Using electrochemical impedance spectroscop (EIS) and polarization curve technique, the electrochemical behavior of prestressed reinforcement under different stress levels was studied in simulated concrete solution. The results show that: As the stress increasing, the impedance spectroscopy changes significantly, the entire impedance spectroscopy shows an elongated semi-circular deformation, high-frequency capacitance arc radius corrosion decreases with the corrosion progress, in other words, the reaction resistance decreases, the corrosion rate of the sample increases. And when the galvanized steel is in 1064MPa stresss condition, corrosion current density reaches the maximum, is 9 times larger than that of none stress corrosions condition. Under the combined effects of the external stress and corrosive media, dislocation can be emitted, value-added and moves. When it reached a critical state, it would lead to the crack nucleation of Stress corrosion cracking (SCC).
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Bilčík, Juraj, and Ivan Hollý. "Experimental Analysis of Reinforcement Corrosion on Bond Behaviour." Advanced Materials Research 1106 (June 2015): 140–43. http://dx.doi.org/10.4028/www.scientific.net/amr.1106.140.
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The corrosion of reinforcement is the major cause of damage of reinforced concrete structures. This has an impact on safety, serviceability and durability of the structure. The corrosion of steel in concrete reduces the cross sectional area of the reinforcement and decreases the bond between reinforcement and concrete. Corrosion products have a higher volume than steel, which produces internal stresses that lead to the cracking and spalling of the concrete cover. The paper analyses the effect of the chloride-initiated corrosion of reinforcements on bond behaviour.
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Singla, Yogesh K., Rahul Chhibber, Avdesh, Shweta Goyal, and Vipin Sharma. "Influence of single and dual particle reinforcements on the corrosion behavior of aluminum alloy based composites." Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications 232, no. 6 (March 15, 2016): 520–32. http://dx.doi.org/10.1177/1464420716638111.
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This article presents the results of a study on the corrosion characteristics of the single and dual particle reinforced aluminum alloy 6063 based composites. The reinforcements of silicon carbide and zircon sand were utilized to fabricate the composites by stir casting technique. The influence of reinforcement and their weight percentage on the hardness variations was investigated. The electrochemical tests in sodium chloride solution were conducted to study the corrosion performance of reinforced composites and base alloy. From the corrosion analysis, it was observed that the single particle reinforcement offered better solution on enhancing the corrosion resistance of base aluminum alloy in comparison with dual particle reinforced composites. In the single particle reinforced composites, addition of zircon sand exhibited increased corrosion resistance, when compared to silicon carbide reinforced composites. The governing mechanism behind increased corrosion resistance was found to be the absence of galvanic coupling between the elemental compounds and the corrosive media at particle–matrix interface. The scanning electron microscopy of composites was performed to analyze corrosion mechanism and correlated well with the corrosion behavior.
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Zhou, Jun Long, Zhong Wen Ou, Qiao Chen, and Yun Chen. "The Influence of Admixtures on the Corrosion Protection Afforded Steel Reinforcement in Seawater-and-Seasand Concrete." Advanced Materials Research 250-253 (May 2011): 81–89. http://dx.doi.org/10.4028/www.scientific.net/amr.250-253.81.
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It is inevitable for steel reinforcement to be corroded when mixed with seawater-and-seasand concrete. In order to improve steel corrosion protection properties of seawater-and-seasand concrete, reduce the chloride ion’s attack on steel reinforcement in structural concrete and lengthen the steel reinforcement’s service time, this paper presents an experimental study on whether admixtures like fly ash, slag and metakaolin in the seawater-and-seasand could retard the corrosion to steel reinforcement and provide protection to steel reinforcement in seawater-and-seasand concrete. The results indicated that metakaolin had a significant anti-corrosion effect and greatly enhanced the steel corrosion protection properties of seawater-and-seasand concrete whereas both fly ash and slag did not appear to have any obvious influence on curbing the corrosion of steel reinforcement.
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Yamamoto, Takashi, Satoshi Takaya, and Toyo Miyagawa. "Influence of Corrosion Distribution on Estimation of Flexural Loading Capacity of Corroded RC Beams." Journal of Disaster Research 12, no. 3 (May 29, 2017): 478–86. http://dx.doi.org/10.20965/jdr.2017.p0478.
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A load carrying capacity of the reinforced concrete (RC) member is degraded by the corrosion of reinforcing steel bars due to chloride ion ingress. A lot of researches on the effect of corrosion in the longitudinal tensile reinforcing steel bars on the load carrying behavior have been available up to now. Accurate and quantitative estimation of capacity, however, is often difficult, because of the non-uniformity of corrosion in the member. Thus, a relationship between the spatial distribution of corrosion in the reinforcement including its scatter and the flexural loading capacity of RC member with such distribution of corrosion should be clarified so that the flexural capacity of corroded RC member can be estimated accurately. On the other hand, in case of the practical RC member under the corrosive environment, it should be considered that the flexural capacity often have to be derived from not a large number of inspection data on cross sectional areas of corroded reinforcements. So, in this study, a flexural loading test was performed by using RC beam specimens with the corroded tensile reinforcements provided the distribution of sectional areas. An estimation method of the flexural capacity of corroded RC beam was also shown, considering the distribution and its scatter in sectional areas of corroded reinforcements under the limited inspection data. Furthermore, the estimation of the longitudinal distribution of the cross sectional area of corroded reinforcement was performed by the spatial interpolation using Kriging method. Test results showed the yield and maximum load capacity in the corroded RC beam decreased as the corrosion rate increased. The failure mode of rupture in the reinforcement was shown in the large corrosion. The proposed estimation method was able to lead the safe evaluation of those experimental flexural capacities, determining the appropriate longitudinal characteristic value of the cross sectional area of corroded reinforcement. The flexural capacity can be also safely calculated using the characteristic value of diameters estimated by the corrosion crack width on the surface of the concrete, while the ratio of the experimental flexural capacity to the estimated one decreased as the corrosion loss increased. The distribution of bar diameters in the corroded reinforcement was able to be roughly estimated by using Kriging method. However, it was suggested that the measurement points close to the minimum bar diameter should be included to estimate the flexural capacity on the safe side.
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Hollý, Ivan. "Experimental Investigation of Bond between GFRP Reinforcement and Concrete." Solid State Phenomena 309 (August 2020): 140–45. http://dx.doi.org/10.4028/www.scientific.net/ssp.309.140.
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The reinforcing steel embedded in concrete is generally protected against corrosion by the high alkalinity (pH = 12.5 to 13.5) of the concrete pore solution. The structural degradation of concrete structures due to reinforcement’s corrosion has an impact on the safety, serviceability and durability of the structure. The corrosion of reinforcements in the construction of a transport infrastructure (especially bridges), parking areas, etc., is primarily initiated by chlorides from de-icing salts. Glass fiber reinforcement polymer (GFRP) bars are suitable alternatives to steel bars in reinforced concrete applications. The bond between concrete and reinforcement is one of the basic requirements for the composite action of both materials. The transfer of forces between the steel reinforcement and the concrete is provided by the following mechanisms: adhesion, friction and mechanical interlocking. The bond between GFRP reinforcement and concrete is different and it is ensured by friction and mechanical interlocking of the rebar surface. The chemical bond does not originate between GFRP reinforcement and the surrounding concrete, so adhesion does not contribute to transfer of the bond forces. Some few test methods are used to determine the bond between GFRP reinforcement and concrete. The pull-out tests were used to determine the bond behavior between GFRP rebars and concrete. This paper describes the preparation, process, results and evaluation of the pull-out tests.
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BALESTRA, C. E. T., M. G. LIMA, A. Z. MENDES, and R. A. MEDEIROS-JUNIOR. "Effect of corrosion degree on mechanical properties of reinforcements buried for 60 years." Revista IBRACON de Estruturas e Materiais 11, no. 3 (May 2018): 474–98. http://dx.doi.org/10.1590/s1983-41952018000300003.
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Abstract This paper studies the influence of the corrosion degree calculated by the mass loss and by the smaller diameters on the yield strength, ultimate strength and final elongation. Reinforcements buried and naturally corroded for 60 years were studied. The mechanical properties of the protruding reinforcing steel were compared to reference bars, which also remained buried for 60 years, but without going through the corrosion process. Micrographs, besides the chemical composition and the characterization of the aggressiveness of the soil were realized. The micrographs and the chemical composition show the presence of pits in the reinforcements and sulfur contents for steel above the prescriptions of the time when the foundations were initially implement, respectively. The results also show that the effects of pitting corrosion on the mechanical properties of the naturally corroded bars may not be adequately expressed by the mass loss. This type of corrosion (pits) produces geometric variations in the cross sections along the length of the test specimens, generating stress gradients between successive sections. This has a noticeable impact on the mechanical properties of the reinforcements. In general, the effects of corrosion are more pronounced on the ductility of the reinforcement. Regarding the aggressiveness of the soil, high corrosion rates were identified in the reinforcement, even with the soil being classified as essentially non-corrosive.
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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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Da, Bo, Hongfa Yu, Haiyan Ma, and Zhangyu Wu. "Reinforcement corrosion research based on the linear polarization resistance method for coral aggregate seawater concrete in a marine environment." Anti-Corrosion Methods and Materials 65, no. 5 (September 3, 2018): 458–70. http://dx.doi.org/10.1108/acmm-03-2018-1911.
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Purpose This paper aims to reduce the cost, limit the time and increase raw material source availability, coral aggregate seawater concrete (CASC) composed of coral, coral sand, seawater and cement can be widely used for the construction of ports, levees, airports and roads to achieve practical engineering values. However, the naturally porous coral structure and abundant Cl− in the seawater and coral lead to extremely severe reinforcement corrosion for CASC. It is well known that Cl− is the main cause of reinforcement corrosion in the marine environment. Therefore, it is necessary to research the reinforcement corrosion of CASC in the marine environment. Design/methodology/approach In this study, linear polarization resistance was adopted to test the linear polarization curves of reinforcement in CASC with different exposure times. Ecorr, Rp, Icorr and Vcorr were calculated according to the weak electrochemical polarization theory and Stern–Geary formula. The effects of concrete cover thickness, exposure time, reinforcement types and inhibitor on reinforcement corrosion in CASC were analysed. The reinforcement corrosion degradation rule was determined, which provided theoretical support for the durability improvement, security assessment, service life prediction and service quality control of CASC structures in marine islands and reef engineering. Findings The corrosion resistance was enhanced with increased concrete cover thickness, and the concrete cover thickness for organic new coated steel should be at least 5.5 cm to reduce the reinforcement corrosion risks in CASC structures. The corrosion resistance of different types of reinforcements followed the rule: 2205 duplex stainless steel > 316 stainless steel > organic new coated steel > zinc-chromium coated steel > common steel. In the early exposure stage, the anti-corrosion effectiveness of the calcium nitrate inhibitor (CN) was superior to that for the amino alcohol inhibitor (AA). With the extension of exposure time, the decreasing rate of anticorrosion effectiveness of CN was higher than that of AA. Originality/value Reinforcement corrosion of CASC in a marine environment was studied. Concrete cover thickness, exposure time, reinforcement type and inhibitor influenced the reinforcement corrosion were investigated. New technique of reinforcement anti-corrosion in marine engineering was proposed. Possible applications of CASC in marine engineering structures were suggested.
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Kotes, Peter, Josef Vican, Miroslav Brodnan, and Ružica Nikolič. "Reliability of Existing Concrete Bridges from the Aspect of the Reinforcement Corrosion." Key Engineering Materials 691 (May 2016): 119–28. http://dx.doi.org/10.4028/www.scientific.net/kem.691.119.
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The quality and durability of the concrete structures are affected by many degradation processes. The reliability of existing bridge structures is significantly affected by numerous factors, from which the reinforcement and structural steel corrosion, together with effect of traffic action, are the most important. Corrosion is the destructive attack on metal by chemical or electrochemical reaction with its environment. In the case of reinforced concrete (RC) structures, the most known degradation process is corrosion of reinforcement. RC members have to fulfill the conditions given in Eurocode [1, 2]. Horizontal beams are mainly subjected to bending and shear. The paper deals with reinforcement corrosion of main longitudinal reinforcements (reinforcement against bending) and its influence on the moment resistance of the existing bridge concrete structures. The two types of active stage calculation of corrosion were considered in this paper. The length of passive stage was not known, so it was calculated backwards.
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Hao, Bao Hong, Ding Zeng, Hang Li, Yu Xue Cheng, and Yan Tao Dou. "Model Research of Concrete Reinforcement Corrosion Mechanism and Corrosion Rate under the Corrosion of Chloride Ion." Applied Mechanics and Materials 470 (December 2013): 847–53. http://dx.doi.org/10.4028/www.scientific.net/amm.470.847.
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This paper researches law of reinforcement corrosion under chloride environment based on method the simulated accelerated test. Test the self-corrosion current density and electrode potential quantitative index of concrete reinforcement under chloride environment and establish quantitative model of corrosion time and reinforcement corrosion quantity by means of advanced linear polarization method and electrochemical testing method. Corroded reinforcement weight loss ratio under chloride environment is detected in physical way, combined with reinforcement corrosion layer microstructure and composition characteristics detected by scanning electron microscope. Both of the above deeply reveals corrosion mechanism and corrosion characteristics of the reinforcement. Corrosion rate theoretical model and statistical model have been revised. The research results prove that reinforcement corrosion rate has increased by an average of 4-5 times under chloride environment, weight loss ratio has increased by 15% compared with that under no-chloride environment, and due to chlorine’s effect, partial and uneven corrosion rust layer appears on surface of the reinforcement, which will be the direct cause of inducing accelerating corrosion of reinforcement at the later stage.
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Dauji, Saha. "Reinforcement corrosion in coastal and marine concrete: A review." Challenge Journal of Concrete Research Letters 9, no. 2 (June 8, 2018): 62. http://dx.doi.org/10.20528/cjcrl.2018.02.003.
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Concrete is used as a structural material for construction of buildings, jetties, harbors, etc. in many coastal and marine locations. The reinforcement used in concrete is susceptible to corrosion, resulting in loss of steel area, loss of bond, expansion of the reinforcement volume leading to cracking or spalling of concrete. Marine environment induces higher corrosion of reinforcement, compared to in-land locations. Concrete exposed to tidal fluctuations, or to the action of waves and currents are among the most severely affected. Corrosion of reinforcement in concrete is of major concern in coastal and marine environment. Control and monitoring of corrosion is a big challenge to engineers. In the recent years, different investigators reported their studies in this area. Depending on the severity of the exposure conditions, different corrosion inhibitors and protection methods have been attempted with varying degrees of success. The present article presents a generic review of the corrosion issues in marine concrete. Drawing from the experiences of the various researchers, the corrosion measurements, and corrosion control schemes, including use of coated reinforcements and corrosion inhibitors are discussed. The durability performance based design of concrete in the probabilistic framework and the life cycle cost analysis for durability design decisions have been identified as the future direction of corrosion protection of coastal and marine structures.
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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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O’Donovan, Ross, Brian D. O’Rourke, Kieran D. Ruane, and John Justin Murphy. "Anaerobic Corrosion of Reinforcement." Key Engineering Materials 569-570 (July 2013): 1124–31. http://dx.doi.org/10.4028/www.scientific.net/kem.569-570.1124.
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Anaerobic corrosion of steel reinforcement is rarely reported and limited literature is available on the subject. Corrosion of steel is an electrochemical process requiring a supply of oxygen in the presence of moisture. Steel corrosion product usually occupies a much larger volume than the un-corroded steel resulting in cracked or spalled concrete. If the supply of oxygen is restricted, black rust may be formed by the process of anaerobic corrosion. Black rust is not expansive, which makes it particularly difficult to detect in reinforced concrete. This paper presents a case study of anaerobic corrosion in the Mizen Bridge, together with an in-depth review of anaerobic corrosion of reinforcement in concrete, outlining black rust formation, characteristics and detection methods.
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Lee, Han Seung, Je Woon Kyung, and Sung Bok Lee. "Study on the Mechanical Properties of Reinforcement Damaged by Reinforcement Corrosion." Key Engineering Materials 348-349 (September 2007): 433–36. http://dx.doi.org/10.4028/www.scientific.net/kem.348-349.433.
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This study was carried out to investigate quantitatively the relationship between the degree of reinforcement corrosion and the mechanical properties of reinforcement. In the experiment, the tensile test of corroded reinforcement was conducted at the different stage of the degree of reinforcement corrosion. As a result, it was found that the chloride-induced corrosion induce the pitting and the corrosion using electrical current induce the uniform corrosion. As the degree of reinforcement corrosion increased, the nominal yield point and nominal elastic modulus both decreased. Also, there were very high correlations between the degree of reinforcement corrosion and the mechanical properties of reinforcement. We could make the material constitutive laws for the mechanical properties of reinforcement as a function of the degree of reinforcement corrosion to analyze the damaged RC members with reinforcement corrosion using finite element method.
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Jiang, Quan, Yu Jun Liu, and Ru Ping Liu. "Durability Assessment of Hot Dip Galvanized Reinforcement Concrete." Advanced Materials Research 177 (December 2010): 533–36. http://dx.doi.org/10.4028/www.scientific.net/amr.177.533.
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Treat the steel bars by hot dip galvanizing technology to prepare steel concrete specimen. Adopt artificial accelerated corrosion test to simulate the seawater corrosive environment in continuous immersion zone and tidal zone and carry out accelerated corrosion for the concrete bars. Add NaCl whose cement content is 1%, 5% and 7% respectively in the concrete specimen to improve the chloride ion content in the system and simulate the strong corrosion environment. This thesis examines the corrosion influence of chloride ion penetration on the ordinary bars and hot-dip steel bars. It also assesses the corrosion protection efficiency for hot dip galvanized reinforcement (HDGR) by half cell method and analyzes the test results.
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Basdeki, Maria, and Charis Apostolopoulos. "Mechanical Behavior Evaluation of Tempcore and Hybrid Reinforcing Steel Bars via a Proposed Fatigue Damage Index in Long Terms." Metals 11, no. 5 (May 19, 2021): 834. http://dx.doi.org/10.3390/met11050834.
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As it is widely known, corrosion constitutes a major deterioration factor for reinforced concrete structures which are located in coastal areas. This phenomenon, combined with repeated loads and, especially, intense seismic events, negatively affect their useful service life. It is well known that the microstructure of steel reinforcing bars has a significant impact either on their corrosion resistance or on their fatigue life. In the present manuscript, an effort has been made to study the effect of corrosive factors on fatigue response for two types of steel reinforcement: Tempcore steel B reinforcing bars and a new-generation, dual-phase (DP) steel F reinforcement. The findings of this experimental study showed that DP steel reinforcement’s rate of degradation due to corrosion seemed apparently lighter than Tempcore B with respect to its capacity to bear repeated loads to a satisfactory degree after corrosion. For this purpose, based on a quality material index that characterizes the mechanical performance of materials, an extended damage material indicator for fatigue conditions is similarly proposed for evaluating and classifying these two types of rebars in terms of material quality and durability. The outcomes of this investigation demonstrated the feasibility of fatigue damage indicators in the production cycle as well as at different exposure times, once corrosion phenomena had left their mark in steel reinforcement.
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Zhang, Lu, Ditao Niu, Bo Wen, and Daming Luo. "Concrete Protective Layer Cracking Caused by Non-Uniform Corrosion of Reinforcements." Materials 12, no. 24 (December 17, 2019): 4245. http://dx.doi.org/10.3390/ma12244245.
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The volume expansion of reinforcement corrosion products resulting from the corrosion of steel reinforcement embedded into concrete causes the concrete’s protective layer to crack or spall, reducing the durability of the concrete structure. Thus, it is necessary to analyze concrete cracking caused by reinforcement corrosion. This study focused on the occurrence of non-uniform reinforcement corrosion in a natural environment. The characteristics of the rust layer were used to deduce the unequal radial displacement distribution function of concrete around both angular and non-angular bars. Additionally, the relationship between the corrosion ratio and the radial displacement of the concrete around the bar was established quantitatively. Concrete cracking due to the non-uniform corrosion of reinforcements was simulated using steel bars embedded in concrete that were of uneven displacement because of rust expansion. The distribution of the principal tensile stress around the bar was examined. A formula for calculating the critical radial displacement at the point when cracking began was obtained and used to predict the corrosion ratio of the concrete cover. The determined analytical corrosion ratio agreed well with the test result. The effect factor analysis based on the finite element method indicated that increasing the concrete strength and concrete cover thickness delays concrete cracking and that the adjacent rebar causes the stress superposition phenomenon.
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Ahlborn, Theresa M., and Timothy C. DenHartigh. "Comparative Bond Study of Stainless and High-Chromium Reinforcing Bars in Concrete." Transportation Research Record: Journal of the Transportation Research Board 1845, no. 1 (January 2003): 88–95. http://dx.doi.org/10.3141/1845-10.
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Concrete bridge decks in corrosive environments have used several methods to prevent corrosion of the reinforcing steel including the use of alternative steels as reinforcement. While research has been conducted on corrosion resistance, very little information is available about the bond strength of alternative metallic reinforcement such as solid stainless steels and high-strength, high-chromium (HSHC) alloys. Therefore, the tensile bond strengths of three alternative metallic steel reinforcements in concrete are compared with conventional A615 Grade 60 steel reinforcement. Two types of stainless steel were considered, 316LN and 2205 duplex. An HSHC microcomposite bar was also considered. A total of 250 bond tests were performed with beam-end specimens similar to the ASTM A944 specimen. Bonded lengths of 4 to 12 in. were used for No. 4 and No. 6 reinforcing bars. Concrete clear cover for all tests was 1½ in. to produce cracking bond failure. No transverse reinforcement was present. The normal strength concrete was typical of that used in Michigan bridge decks. Statistical comparisons of bond test results with predicted values for bond strength of A615 reinforcement revealed there was no reason to believe the bond strength of the alternative metallic reinforcing bars was less than predicted. The conservatism of the current development-length relationships generally predicted lower bond strengths than were observed. Therefore, no modifications are suggested when estimating the development length of these reinforcements as a one-to-one replacement for A615 Grade 60 reinforcement, No. 4 to No. 6 bars, using standard development-length relationships.
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Li, Xiaozhen, Hui Wang, Jianmin Wang, and Junzhe Liu. "Experimental Analysis of Reinforcement Rust in Cement under Corrosive Environment." Coatings 11, no. 2 (February 18, 2021): 241. http://dx.doi.org/10.3390/coatings11020241.
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In this work, the microstructure characteristics of corrosion products of reinforcement under a corrosive environment with chloride, carbonation and the combination of chloride-carbonization were studied by x-ray photoelectron spectroscopy (XPS) and scanning electron microscopy/energy spectroscopy (SEM-EDX). The results indicate that the outside of the passivation film reacts with the cement slurry to produce Fe–SiO4 in all three corrosive environments. The inner side is not completely corroded. The morphology of the corrosion is different in the three environments. In a chloride environment, corrosion products have obvious cracks, and the local layered structure is dense. In a carbonation environment, the surface of the steel corrosion shows a uniform granular structure and loose texture. With the combination of chloride and combination, the surface of the structural layer of steel corrosion was uneven and accompanied by protrusions, cracking and spalling occurred. The composition of the corrosion substances in the three corrosion environments are mainly composed of FeO, Fe3O4, Fe2O3 and Fe–SiO4. The content of iron oxide increases from a chloride salt, carbonization to the composite environment, indicating that the corrosion degree intensifies successively.
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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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Zeng, Ding, Hong Yu Lu, Bao Hong Hao, Hao Zheng Yu, and Yu Mi. "Experimental Study and Mechanism on the Corrosion of Stressed Reinforcement Bars." Key Engineering Materials 837 (April 2020): 109–15. http://dx.doi.org/10.4028/www.scientific.net/kem.837.109.
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In order to understand the influence of the tensile stress on the corrosion of reinforcement bars in civil engineering, the reinforcement bars specimens were put into the liquid corrosion tank made of hydrochloric acid and distilled water by applying the tension stress on the reinforcing frame to carry out rapid corrosion. The corrosion of reinforcement bars under different tension stresses was tested by using electrochemical polarization method. The metallographic examination of reinforcement bars was carried out through the section of reinforcement bars. The corrosion mechanism of the stressed reinforcement bar was tested and analyzed. It can be known from the experimental study: First in the same corrosion condition, the larger the tensile stress is, the faster the corrosion of steel bar will be; Second corrosion current density or corrosion rate are index for evaluating corrosion rate of reinforcement bars with different tensile stresses. Corrosion potential can not be used as an index for evaluating corrosion rate of reinforcement bars with different tensile stresses; Third intercrystalline corrosion occurs inside the reinforcement bar due to micro-defects after rolling and moulding, which directly affects the mechanical properties of reinforcement bar.
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Shen, Jiansheng, Xi Gao, Bo Li, Kun Du, Ruoyu Jin, Wei Chen, and Yidong Xu. "Damage Evolution of RC Beams Under Simultaneous Reinforcement Corrosion and Sustained Load." Materials 12, no. 4 (February 20, 2019): 627. http://dx.doi.org/10.3390/ma12040627.
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To accurately obtain the performance of concrete structures in coastal regions, it is necessary to correctly understand the damage evolution law of reinforced concrete (RC) members under real working conditions. In this paper, four RC beams, subjected to different levels of corrosion and sustained load, are first tested. Reinforcement corrosion coupled with sustained load increases the number and width of cracks at the soffit of beams but decreases their loading capacities. Crack width of the corroded beam under 50% of designed load is two times of that under 30% of designed load. Residual loading capacities of the corroded beams subjected to 30% and 50% of designed load are 87.5% and 81.8% of the control beam. A finite element model is developed for the corroded RC beams. Due to less confinement, concrete below and at the sides of reinforcements is subjected to a higher stress, compared to concrete above the reinforcements. Corrosion expansion of reinforcements is successfully modelled by a temperature-filed method, as it properly simulates the damage evolution of the corroded RC beams. As a result, concrete cracking, caused by the reinforcement corrosion, is well captured. Coupling reinforcement corrosion with sustained load significantly increases the damage level in RC beams, particularly for those subjected to a high sustained load. The whole damage evolution process of concrete cracking due to corrosion expansion under the coupling effect of sustained loading and environment can be simulated, thus providing a reference for the durability evaluation, life prediction, and numerical simulation of concrete structure.
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Brodnan, Miroslav, Peter Koteš, Jan Vanerek, and Rostislav Drochytka. "Corrosion determination of reinforcement using the electrical resistance method." Materiali in tehnologije 51, no. 1 (February 14, 2017): 85–93. http://dx.doi.org/10.17222/mit.2015.217.
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Zhou, Xiang, Wei Long, and Xiaoping Zhou. "Study on microstructure and mechanical properties of Fe-based amorphous particle-reinforced Al-based matrix composites." Advanced Composites Letters 29 (January 1, 2020): 2633366X2092140. http://dx.doi.org/10.1177/2633366x20921402.
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Fe52Cr15Mo26C3B1Y3 amorphous particle-reinforced pure aluminum (Al) matrix composite was prepared by powder metallurgy. The ferrum (Fe)-based amorphous particles prepared by atomization method have good amorphous structure, and the circular reinforcement particles are evenly distributed in the Al matrix. The composite has high strength, hardness, and excellent corrosion resistance. The hardness of the composite increases gradually with the increase in the content of the reinforcement, from 46 Vickers hardness (HV) of pure Al to 220.5 HV, with remarkable effect. The tensile strength of the composite increases first and then decreases with the increase in the content of the reinforcement. When the content of reinforcement is 15%, the maximum tensile strength is 234 MPa, which is 154% higher than that of pure Al. The fracture mode of the composite is the mixture of plastic fracture and brittle fracture. The corrosion resistance of pure Al is significantly improved by the addition of reinforcements, which shows that the composite has a smaller corrosion current density and a more positive corrosion potential than that of pure Al.
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Dungi, Jagath Kumari, and K. Srinivasa Rao. "A Solution for Corrosion Effect of Durable Concrete Structures." Advanced Materials Research 587 (November 2012): 122–28. http://dx.doi.org/10.4028/www.scientific.net/amr.587.122.
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Corrosion of reinforcements has been one of the major challenges that the civil engineers have been facing. Corrosion leads to the formation of rust which results in the spalling of concrete which in turn leads to the exposure of rebars to the aggressive environment. This will accelerate the ill effects and ultimately leads to the breakdown of the structure. Corrosion mainly occurs in areas of aggressive environment such as coastal regions. It was discovered that structures such as highways, bridge decks, parking ramps and marine installations, designed to last from 50 to 100 years, required replacement or extensive repairs in just 10 years. The problem was found to be the absorption of airborne pollutants, acids and chloride salts through the surface which eventually found their way to the reinforcing steel, causing it to corrode. It is very important that corrosion of reinforcement must be prevented in order to have a durable structure. Even though there are many methods to prevent corrosion, most of them are uneconomical and requires great skill. Studies on corrosion of reinforcement in various parts of the world have revealed that High Volume Fly Ash (HVFA) concrete can protect the steel reinforcement effectively, so that it can resist corrosion, and thus the structure as a whole. Similarly coating of rebars is the best and cheapest solution for corrosion attack, because prevention is better than cure. Epoxy coated reinforcement rebar can be used in construction to protect steel more efficiently from corrosion. Epoxy coating works by preventing chlorides and moisture reaching the surface of the steel. So, it is the most practical and scientific way for protecting the steel reinforcement against corrosion effect. This paper reviews the HVFA concrete with fusion bonded epoxy coated rebars is the solution for corrosion effect.
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Constantinescu, Vasile, Rares George Taran, Gheorghe Veniamin Bogus, and Ioan Carcea. "Reinforcement Corrosion to Aggressive Environment." Advanced Materials Research 1036 (October 2014): 71–76. http://dx.doi.org/10.4028/www.scientific.net/amr.1036.71.
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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. In this study we will present how metal acts into an aggressive environment and how we can adopt the best solutions to reduce the attack of corrosion. First we should understand how corrosion occurs. Corrosion occurs when two different metals, or metals in different environments, are electrically connected in a moist or damp concrete. This will occur when: steel reinforcement is in contact with an aluminium conduit; concrete pore water composition varies between adjacent or along reinforcing bars; where there is a variation in alloy composition between or along reinforcing bars; where there is a variation in residual/applied stress along or between reinforcing bars. Loss of alkalinity due to carbonation or chlorides, crack due to mechanical loading, stray currents, agents from atmospheric pollution, moisture pathways, low concrete tensile strength, electrical contact with dissimilar metals are some of the most important reasons of corrosion. Electro-chemical corrosion, which plays a subordinate role in air, is of greater significance in liquids. The extent of electro-chemical corrosion depends on the electrical conductivity of the liquid, which affects the protective influence of the zinc layer over greater or smaller areas. The pH value of the liquid is of most significance. The corrosion rate of zinc is normally low and stable in the pH range of 5,5—12,5, at temperatures between 0 and 20 °C. Corrosion outside this range is usually more rapid. Hard water, which contains lime and magnesium, is less aggressive than soft water. Together with carbon dioxide these substances form sparingly soluble carbonates on the zinc surface, protecting the zinc against further corrosion. Soft water often attacks zinc, since the absence of salts means that the protective layer cannot be formed. In some waters, polarity reversal can occur at about 70 °C so that the zinc coating becomes more electro-positive than the steel and pitting occurs. Oxygen, sulphates and chlorides counteract polarity reversal, which means that the problem may exist only in very clean water. Water temperature is of great significance to the rate of corrosion. Above approximately 55 °C, the layer-forming corrosion products acquire a coarse-grained structure and lose adhesion to the zinc surface. They are easily dislodged and expose new, fresh zinc for continued and rapid corrosion attack. The rate of corrosion reaches a maximum at about 70 °C, after which it declines so that at 100 °C it is about the same as at 50 °C. Keywords : composite materials, corrosion, reinforcement, water corrosion, reinforcement bars.
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Kamaitis, Zenonas. "DAMAGE TO CONCRETE BRIDGES DUE TO REINFORCEMENT CORROSION." TRANSPORT 17, no. 5 (October 31, 2002): 163–70. http://dx.doi.org/10.3846/16483840.2002.10414037.
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The mechanisms of reinforcement corrosion in concrete are the subject of extensive research. Although reliable methods for predicting the corrosive deterioration of concrete structures do not yet exist. This paper describes the durability problem of reinforced concrete bridges based on the mechanisms of carbonation depth or chloride profile. The deterioration model considering concrete carbonation, chloride penetration and concrete cover cracking is adopted to describe the service life of concrete structures. The corrosion models include environmental conditions, concrete carbonation or chloride diffusion rates, quality of concrete cover, steel corrosion rates and many other factors that make the predicting of service life of structures extremely difficult. Finally, the author gives the details of the methods of durabilio/ verification and the proposals for its including in the national standards and practical guides.
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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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Murakami, Flavia de Fatima Emi, Elizamary Otto Ferreira, Carlos Eduardo Tino Balestra, and Gustavo Savaris. "Resistência à tração de barras de aço corroídas." Semina: Ciências Exatas e Tecnológicas 42, no. 1 (June 30, 2021): 103. http://dx.doi.org/10.5433/1679-0375.2021v42n1p103.
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Among the pathological manifestations associated with reinforced concrete, corrosion of the reinforcement is one of the most serious issues since it is related to the durability of the structures and the safety of the users. Although the reinforcement in the structural components is protected by a covering layer, carbonation or the presence of chlorides in the concrete generates necessary conditions for corrosion of the reinforcement. This causes a reduction in the cross section and the generation of products that, due to their volumetric expansion, cause cracks in the interior of the concrete. This work evaluates the effects of corrosion on mechanical properties of corroded reinforcements through accelerated conditions in the laboratory. Steel bars installed inside cylindrical concrete specimens are subjected to accelerated corrosion, immersed in a saline solution with the application of an electric current for periods of 1, 3, 5 and 7 d. After corrosion, the steel bars are removed and their weight loss, degree of corrosion and tensile strength are evaluated. The results demonstrate an increased degree of corrosion with exposure time to the saline solution and the non-uniform reduction of the tensile strength of the bars due to the formation of corrosion pits with varying depth along the bar.
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VEDABOURISWARAN, G., S. ARAVINDAN, and P. SATHYA. "GENERATION OF SURFACE COMPOSITES AND CORROSION CHARACTERIZATION OF Mg RZ 5 ALLOY CONTAINING RARE EARTH ELEMENTS." Surface Review and Letters 27, no. 09 (February 11, 2020): 1950200. http://dx.doi.org/10.1142/s0218625x19502007.
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Surface composites are developed on Mg RZ 5 alloy by friction stir processing. During FSP, hard reinforcements are introduced into the matrix of RZ 5 alloy and dispersed uniformly by mechanical stirring action. The reinforcements dispersed were boron carbide, carbon nanotubes (multi-walled) and an 80:20 mixture of zirconia and alumina particles. Dynamic recrystallization and grain boundary pinning action by reinforcement particles resulted in the generation of fine-grained surface composites. Corrosion characteristics of the base material and the surface composites are studied by potentiodynamic polarization technique. The corrosion rates estimated for the surface composites are found to be far lesser than the base material while their polarization resistances were higher than the base material. Among all surface composites, B4C particle reinforced surface composites exhibited the lowest corrosion rate of [Formula: see text]15 mpy. Reduction in the corrosion rate of the surface composites is influenced by fine-grained microstructure and presence of harder reinforcement particles.
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Lollini, Federica, Maddalena Carsana, Matteo Gastaldi, and Elena Redaelli. "Corrosion behaviour of stainless steel reinforcement in concrete." Corrosion Reviews 37, no. 1 (January 28, 2019): 3–19. http://dx.doi.org/10.1515/corrrev-2017-0088.
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AbstractIn Europe, stainless steel rebars have been used since the mid-80s, whilst in North America, their use has been progressively growing only since the mid-90s. Due to their higher resistance to corrosion in comparison to ordinary black steel bars, they have been employed in a wide number of applications worldwide to achieve the durability performance of reinforced concrete structures, especially in extremely corrosive marine environments or when long service lives are required. In this paper, a state of the art on the corrosion resistance of stainless steel bars is reported. In particular, the contribution of Professor Luca Bertolini in this research field is considered. Initially, different testing methods are presented to point out their advantages and limitations and then the results on corrosion behaviour of different grades of stainless steel bars (i.e. austenitic, ferritic and duplex), obtained especially with tests in concrete, are analysed. Afterwards, some of the recent applications of stainless steel bars are illustrated.
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Raczkiewicz, Wioletta, Artur Wójcicki, and Adam Wójcicki. "Using the galvanostatic pulse method to estimate the corrosion of reinforcement in structural elements." South Florida Journal of Development 2, no. 3 (August 9, 2021): 4865–76. http://dx.doi.org/10.46932/sfjdv2n3-080.
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ABSTRACT
Early steel bars corrosion in reinforced concrete elements is difficult to detect because of the lack of visible changes on the concrete surface. To assess reinforcement corrosion risk level without structure damage some non-destructive diagnostic methods are applied. One of them is the galvanostatic pulse method. This semi-non-destructive electrochemical method allows to determine the corrosion areas and estimate the steel bars corrosion activity. Using this method it is possible to measure some electrical parameters (corrosion current density, stationary potential and reinforcement concrete cover resistivity) that allow to indirectly estimate the reinforcement corrosion progress in concrete. So far this method has been generally applied to bridges. The article presents results of studies in which the galvanostatic pulse method was used to determine reinforcement corrosion risk in structures elements different than bridges. Two types of reinforced concrete columns were tested under different environment conditions and two groups of laboratory specimens which were subjected to freezing and thawing cycles in NaCl solution or stayed in natural air–dry conditions. The apparatus GP-5000 GalvaPulseTM was used. Based on the obtained results the conclusions were drawn. The galvanostatic pulse method allows to assess the progress of the reinforcement corrosion process in tested elements. However, it is necessary to measure simultaneously all parameters and make their complex analysis.
RESUMEN
La corrosión temprana de las barras de acero en elementos de hormigón armado es difícil de detectar debido a la falta de cambios visibles en la superficie del hormigón. Para evaluar el nivel de riesgo de corrosión de la armadura sin dañar la estructura se aplican algunos métodos de diagnóstico no destructivos. Uno de ellos es el método del pulso galvanostático. Este método electroquímico semi no destructivo permite determinar las áreas de corrosión y estimar la actividad de corrosión de las barras de acero. Utilizando este método es posible medir algunos parámetros eléctricos (densidad de corriente de corrosión, potencial estacionario y resistividad de la cubierta del hormigón de la armadura) que permiten estimar indirectamente el progreso de la corrosión de la armadura en el hormigón. Hasta ahora este método se ha aplicado generalmente a los puentes. El artículo presenta los resultados de estudios en los que se utilizó el método de impulsos galvanostáticos para determinar el riesgo de corrosión de las armaduras en elementos de estructuras diferentes a los puentes. Se ensayaron dos tipos de columnas de hormigón armado en diferentes condiciones ambientales y dos grupos de probetas de laboratorio que se sometieron a ciclos de congelación y descongelación en solución de NaCl o permanecieron en condiciones naturales de secado al aire. Se utilizó el aparato GP-5000 GalvaPulseTM. A partir de los resultados obtenidos se extrajeron las siguientes conclusiones El método de impulsos galvanostáticos permite evaluar el progreso del proceso de corrosión de la armadura en los elementos ensayados. Sin embargo, es necesario medir simultáneamente todos los parámetros y realizar su complejo análisis.
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Warkus, J., and M. Raupach. "Modelling of reinforcement corrosion – Corrosion with extensive cathodes." Materials and Corrosion 57, no. 12 (December 2006): 920–25. http://dx.doi.org/10.1002/maco.200604032.
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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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El-Assal, Ahmed. "Corrosion of Prestrained Reinforcement Steel." Journal of King Abdulaziz University-Engineering Sciences 16, no. 2 (2005): 3–14. http://dx.doi.org/10.4197/eng.16-2.1.
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Osterminski, Kai, and Peter Schießl. "Design model for reinforcement corrosion." Structural Concrete 13, no. 3 (September 2012): 156–65. http://dx.doi.org/10.1002/suco.201200003.
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Tondolo, F. "Bond behaviour with reinforcement corrosion." Construction and Building Materials 93 (September 2015): 926–32. http://dx.doi.org/10.1016/j.conbuildmat.2015.05.067.
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Han, Sun-Jin, Hyo-Eun Joo, Seung-Ho Choi, Inwook Heo, Kang Kim, and Soo-Yeon Seo. "Experimental Study on Shear Capacity of Reinforced Concrete Beams with Corroded Longitudinal Reinforcement." Materials 12, no. 5 (March 12, 2019): 837. http://dx.doi.org/10.3390/ma12050837.
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In this study, shear tests were conducted to investigate the effects of longitudinal reinforcement corrosion on the shear capacity of reinforced concrete (RC) members with transverse reinforcement. To this end, a total of eight test specimens were fabricated, and the corrosion rates and anchorage details of rebars were set as test variables. In addition, an accelerated corrosion technique was used to introduce corrosion into the longitudinal reinforcement without corroding shear reinforcement. The test results indicated that the capacities of the specimens in which tension reinforcement was not properly anchored at the ends of the members decreased rapidly at high corrosion rates, whereas the capacities of the specimens in which tension reinforcement was properly anchored by hooks were similar to or higher than those of the non-corroded specimens, despite bond loss caused by corrosion.
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Tamrazyan, Ashot Georgievich, Micheal Sergeevich Mineev, and Aishat Urasheva. "Fire Resistance of Reinforced Concrete Corrosion-Damaged Columns of the "Standard" Fire." Key Engineering Materials 828 (December 2019): 163–69. http://dx.doi.org/10.4028/www.scientific.net/kem.828.163.
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The article describes the features of the effect of corrosion of reinforcement on the bearing capacity of reinforced concrete columns in a "standard" fire. On the basis of the standard calculation method, the fire resistance of the column was estimated under a four-sided fire effect taking into account the different duration of the fire. The study examined the operation of the column in a corrosive environment, it was assumed that the initiation of corrosion of concrete and reinforcement will occur after 10 years of exploitation. It was found that the destruction of concrete protective layer 25 mm thick in a medium aggressive environment will occur after 25 years, and the diameter of the reinforcement during this period will decrease by 20%. To compare the results, a reinforced concrete column with a section of 400x400mm was calculated under the influence of a “standard” fire under normal operating conditions and taking into account work in a corrosive environment. The results of heat engineering calculations are presented, where the temperature changes in the reinforcement depending on the heating time and reduction of the protective layer thickness, as well as the change in the diameter of the reinforcement and its effect on the bearing capacity are shown. It has been established that reducing the cross-sectional area of the working reinforcement and reducing the cross-sectional dimensions of the column due to the occurring corrosion processes leads to a decrease in the fire resistance limit on the loss of bearing capacity by 58%.
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Zaki, Ahmad, Megat Azmi Megat Johari, Wan Muhd Aminuddin Wan Hussin, and Yessi Jusman. "Experimental Assessment of Rebar Corrosion in Concrete Slab Using Ground Penetrating Radar (GPR)." International Journal of Corrosion 2018 (November 21, 2018): 1–10. http://dx.doi.org/10.1155/2018/5389829.
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Corrosion of steel reinforcement is a major cause of structural damage that requires repair or replacement. Early detection of steel corrosion can limit the extent of necessary repairs or replacements and costs associated with the rehabilitation works. The ground penetrating radar (GPR) method has been found to be a useful method for evaluating reinforcement corrosion in existing concrete structures. In this paper, GPR was utilized to assess corrosion of steel reinforcement in a concrete slab. A technique for accelerating reinforcement bar corrosion using direct current (DC) power supply with 5% sodium chloride (NaCl) solution was used to induce corrosion to embedded reinforcement bars (rebars) in this concrete slab. A 2 GHz GPR was used to assess the corrosion of the rebars. The analysis of the results of the GPR data obtained shows that corrosion of the rebars could be effectively localized and assessed.
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Li, Yong, Meng-Fei Xie, and Jing-Bo Liu. "Experimental Study on the Seismic Behaviour of Reinforced Concrete Bridge Piers Strengthened by BFRP Sheets." Advances in Civil Engineering 2019 (July 1, 2019): 1–11. http://dx.doi.org/10.1155/2019/4169421.
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With the continuous development of the ductility capacity concept for seismic design of bridges, the ductility capacity of many existing bridges does not meet the requirements of the current code for seismic performance because of the low reinforcement ratio and reinforcement corrosion of reinforced concrete (RC) piers. Because of their superior mechanical properties and low price, basalt fibre-reinforced polymer (BFRP) sheets have potential application in the seismic retrofits field of existing bridges. To study the seismic strengthening effect of RC pier columns, scaled specimens with standard reinforcement ratios, with low reinforcement ratios according to the past code and with corroded reinforcements, were designed and manufactured and then wrapped and pasted with BFRP sheets on the plastic hinge areas. Pseudostatic tests were conducted to verify the seismic performance of the strengthened and unstrengthened specimens. Experimental results showed that the ultimate flexural capacity, deformation capacity, and energy dissipation capacity of strengthened RC pier columns were superior. Especially for strengthened specimens with low reinforcement ratios or corrosion reinforcement, their seismic performance could rival than that of columns with standard reinforcement ratios, which showed the advantage of BFRP sheets in the seismic retrofitting of existing bridge piers.
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Holly, Ivan, Katarina Gajdosova, and Robert Sonnenschein. "Reinforcement Corrosion and its Effect on Bond Behaviour." Applied Mechanics and Materials 837 (June 2016): 179–82. http://dx.doi.org/10.4028/www.scientific.net/amm.837.179.
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The corrosion of reinforcement is one of the predominant reasons for loss of reliability of reinforced concrete structures. This has an impact on safety, serviceability and durability of the structure. The corrosion of steel in concrete reduces the cross sectional area of the reinforcement and decreases the bond between reinforcement and concrete. Corrosion products have a higher volume than steel, which produces internal stresses that lead to the cracking and spalling of the concrete cover. Additionally, corrosion of steel changes the mechanical properties of reinforcement. In this paper, the relationship between crack widths and bond strength between reinforcement and concrete was investigated.
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Zhou, Xiu Jing, Jia Ming Shu, Ji Dong Zhang, Yong Xian Yan, and Wei Zhong Gan. "The Impact of Concrete Cover Thickness and Chemical Alkalinity on Reinforcement Corrosion." Advanced Materials Research 1065-1069 (December 2014): 1957–63. http://dx.doi.org/10.4028/www.scientific.net/amr.1065-1069.1957.
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Based on the mechanism of reinforcement corrosion in concrete structures and the experimental measurements of corrosion potential and resistance, this paper investigates the impact of concrete cover thickness and chemical alkalinity on reinforcement corrosion. Experimental results show that the rate of reinforcement corrosion decreases as the thickness of concrete cover of reinforcement increases. Moreover, given no risk of alkali-aggregate reaction, raising the chemical alkalinity of concrete cover helps maintain passivation of reinforcement. Additionally, under general atmospheric conditions, cracks that are not along bars barely affect structural durability if the width of cracks is smaller than its standard limit.
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Konovalova, Viktoriya. "Analysis of the corrosion behavior of steel reinforcement protected by phosphate coatings." MATEC Web of Conferences 329 (2020): 02001. http://dx.doi.org/10.1051/matecconf/202032902001.
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The influence of phosphate coatings on the corrosion behavior of steel reinforcement in a chloride-containing environment was studied to determine the need for additional protection against corrosion. The main indicators of the corrosion rate of steel reinforcement with phosphate coatings in chloride-containing solutions were determined, confirming the high protective properties of these coatings. It was found that the corrosion rate of steel reinforcement protected by phosphate coatings is reduced by 3 times. The processes of electrochemical corrosion of steel reinforcement of strength class A500S from steel grade St3ps in concrete under the influence of aggressive environments containing chloride ions (2 % MgCl2 solution and HCl solution with pH = 5) were studied. The kinetics of the corrosion process of steel reinforcement with and without protective phosphate coatings in solutions of various compositions has been studied. The change in mass of steel reinforcement protected by phosphate coatings is 3-4 times less than that of samples without coating. The surface potential of steel reinforcement with phosphate films changes significantly more slowly than that of unprotected samples.
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Raczkiewicz, Wioletta, and Artur Wójcicki. "Temperature Impact on the Assessment of Reinforcement Corrosion Risk in Concrete by Galvanostatic Pulse Method." Applied Sciences 10, no. 3 (February 6, 2020): 1089. http://dx.doi.org/10.3390/app10031089.
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The electrochemical galvanostatic pulse method (GPM) is used for the evaluation of the degree of corrosion risk of reinforcement in concrete. This non-destructive method enables determining the corrosion promoting conditions through the measurements of reinforcement stationary potential and concrete cover resistivity, and determining the probability of reinforcement corrosion in the tested areas. This method also allows for the estimation of the reinforcement corrosion activity and the prediction of the development of the corrosion process on the basis of corrosion current density measurements. The ambient temperature (and the temperature of the examined element) can significantly affect the values of the measured parameters due to electrochemical character of the processes as well as specific measurement technique. Differences in the obtained results can lead to a wrong interpretation of reinforcement corrosion risk degree in concrete. The article attempts to assess the effect of temperature on the measured parameters while using the galvanostatic pulse method. The GP-5000 GalvaPulseTM set was used. The results of this study confirmed the impact of temperature changes on the values of three measured parameters (reinforcement stationary potential, concrete cover resistivity, and corrosion current density) and contributed to catching the trend of these changes.
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Tan, Nguyen Ngoc, and Nguyen Trung Kien. "An experimental study on the shear capacity of corroded reinforced concrete beams without shear reinforcement." Journal of Science and Technology in Civil Engineering (STCE) - NUCE 15, no. 1 (January 22, 2021): 55–66. http://dx.doi.org/10.31814/stce.nuce2021-15(1)-05.
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The effect of corrosion on the structural behavior of reinforced concrete (RC) beams without stirrups was experimentally investigated. A total of eight medium-scale RC beams were constructed without stirrups. The beams were 150 mm in width, 200 mm in depth, and 1100 mm in length. Test variables included three distinct degrees of corrosion (0%, 3.13%, 4.11%, and 4.93% by mass loss of steel rebar). Six beams were subjected to an accelerated corrosion test, while two beams served as non-corroded control beams. All beams were tested under four-point loading failure after the corrosion stage. The effect of various small degrees of corroded longitudinal reinforcements has been observed for the shear capacity. Test findings found that all tested beams had a brittle failure with tested corrosion degrees. Moreover, corroded beams that are exposed to 3% and 4% average corrosion degree reported having a larger shear capacity of approximately 7% compared to control beams. Lastly, beams with a corrosion degree of about 5% showed a decrease of 10% shear strength and a different failure mechanism with distinguished cracking patterns due to the formation of corrosion cracks along the longitudinal reinforcements.
Keywords:
reinforced concrete beam; reinforcement corrosion; shear strength; no stirrups.
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Zeng, Ding, Bao Hong Hao, and Qi Hui Zeng. "The Study for Non-Destructive Quantification Method of Reinforcement Corrosion Degree Based on Electrochemical Detection and Finite Analysis Technology." Applied Mechanics and Materials 527 (February 2014): 31–36. http://dx.doi.org/10.4028/www.scientific.net/amm.527.31.
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Corrosion of reinforcement is one of the most important factors in causing the damage to reinforced concrete structure and the inestimable economic loss and major security risk to a large number buildings with reinforced concrete structure. In order to overcome the disadvantage of previous service reinforcement which can only be carried out by sizing detection not quantification, this paper puts forward to a new method to evaluate non-destructive quantification of corrosion degree of reinforcement based on the combination of electrochemical detection and finite element analysis, thus the effective corresponding can be produced among reinforcement corrosion rate, potential signal and reinforced concrete structural distortion. The relation among corrosion current density and potential characteristic parameters as well as corrosion ratio has been established. Through the finite element analysis technique and the combination with the case analysis, the relation model between the strain rate of concrete beams and detection signal has been built; the forecasted empirical formula for change of strain value of tested reinforcement has been given And by means of verifying the reliability of model with data of previous experiments, the quantitative calculation of reinforcement corrosion degree has been realized, which lays the technical foundation for the research and development of non-destructive detection equipment of corrosion of reinforcement.
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Warkus, J., and M. Raupach. "Modelling of reinforcement corrosion - geometrical effects on macrocell corrosion." Materials and Corrosion 61, no. 6 (November 9, 2009): 494–504. http://dx.doi.org/10.1002/maco.200905437.
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