scholarly journals Corrosion of steel in concrete due to one and two dimensional chloride ingress

2018 ◽  
Vol 199 ◽  
pp. 04004
Author(s):  
Ze Gyang Zakka ◽  
Mike Otieno
Keyword(s):  
Corrosion Rate ◽  
Concrete Beams ◽  
Concrete Cover ◽  
Steel Reinforcement ◽  
Chloride Ingress ◽  
Single Crack ◽  
Ongoing Research ◽  
Concrete Resistivity ◽  
Corrosion Of Steel ◽  
Cracked Specimens

This paper presents results of an ongoing research of the effect of 1D and 2D chloride ingress on concrete resistivity and corrosion rate of steel reinforcement. 12 concrete beams made with concrete of binder blend PC(50)/GGBS(50), w/b = 0.40, 10 mm steel reinforcement rods at concrete cover of 20 mm were used in this laboratory based experiment. The steel reinforcement bars were placed at the middle or at an orthogonal corner of the concrete beams subjected to 1D and 2D chloride ingress respectively. A single crack was induced using 3-point bending on one-half of the beams. The beams were exposed to a repeated cycle of 2 weeks ponding in 5% NaCl and then air drying in ambient laboratory condition for 2 weeks. The corrosion rate of both cracked and uncracked specimens exposed to 2D chloride ingress was significantly higher than that of beams exposed to 1D chloride ingress. The uncracked specimens had lower concrete resistivity values compared to the cracked specimens even though higher corrosion rates were measured.

Analisa Pola Kegagalan Balok Beton Menggunakan GFRP Bar Tanpa Selimut Beton

2020 ◽  
Vol 24 (1) ◽  
pp. 11-16
Author(s):  
Saddam - Husein ◽  
Rudy Djamaluddin ◽  
Rita Irmawaty ◽  
Kusnadi Kusnadi
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Concrete Cover ◽  
Steel Reinforcement ◽  
Fiber Reinforced Polymer ◽  
Mode Analysis ◽  
Flexural Capacity ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Gfrp Bar

SADDAM HUSEIN. Analisa Pola Kegagalan Balok Beton Menggunakan GFRP Bar Tanpa Selimut Beton (dibimbing oleh Rudi Djamaluddin dan Rita Irmawaty) Struktur beton bertulang yang menggunakan tulangan baja pada daerah korosif, menjadi rawan terhadap kerusakan atau penurunan kekuatannya akibat korosi.Korosi pada tulangan baja merupakan salah satu faktor penyebab menurunnya kekuatan struktur beton bertulang. Salah satu material yang dikembangkan mengatasi korosi adalah penggunaan material tulangan GFRP (Glass Fiber Reinforced Polymer). Penelitian ini bertujuan untuk menganalisa kapasitas lentur dan pola kegagalan balok beton tanpa selimut dengan menggunakan material tulangan GFRP bar.   Desain penelitian merupakan eksperimental laboratorium dengan rekapitulasi sebanyak 6 sampel yang terdiri dari 2 Balok beton menggunakan tulangan baja dengan selimut beton, 2 balok beton menggunakan tulangan GFRP bar dengan selimut beton, 2 balok beton menggunakan GFRP bar tanpa selimut beton. Metode pengujian dilakukan dengan dengan pengujian lentur statik monotonik dan Analisis data menggunakan uji kondisi retak awal dan kondisi ultimit.   Hasil penelitian ini menunjukkan bahwa kapasitas lentur pada balok dengan tulangan GFRP bar lebih besar dibandingkan dengan balok tulangan baja dan mampu meningkatkan kapasitas lentur balok dalam menahan beban sebesar 39.76 %, pola kegagalan beton yang terjadi pada balok tulangan baja mengalami kegagalan lentur tekan ditandai dengan retakan yang terjadi pada sisi tertekan dan membentuk retakan tegak dengan sumbu netral beton yang tertekan, sedangkan pada balok beton tulangan GFRP tanpa selimut mengalami kegagalan keruntuhan tekan geser dengan kondisi tulangan berdeformasi (bi-linear) dengan retak miring dan secara tiba-tiba menjalar menuju sumbu netral beton yang tertekan sehingga terjadilah keruntuhan secara tiba-tiba.     SADDAM HUSEIN.Failure mode analysis of concrete Beams Using GFRP rebar Without concrete cover (supervised by Rudi Djamaluddin and Rita Irmawaty)   Reinforced concrete that uses rebar steel in corrosive areas, are prone to damage or decreased strength due to corrosion. Corrosion in the steel reinforcement is one of the factors that decreasing strength of reinforced concrete. One of the materials developed to overcome corrosion is the use of GFRP (Glass Fiber Reinforced Polymer) reinforcement material. This study aims to analyze the flexural capacity and failure mode of concrete beams without concrete cover using material GFRP bar as reinforcement.   The research design was an experimental laboratory with a recapitulation of 6 samples consisting of 2 beams using steel reinforcement with concrete cover.2 concrete beams using reinforcement GFRP bar with concrete cover, 2 beams using GFRP bars without concrete cover. The  research method uses the monotonic static flexure and analyzing the data using the initial crack condition and ultimate conditions test.   The results of the research indicate the flexural capacity of the beams with GFRP bar reinforcement is higher than steel reinforcement beams and can increase 39.76% of the flexural capacity of the beams in holding loads , the failure mode analysis occurs in steel reinforcing beam experiences compressive failure. Failure was characterized  by cracks that occur on the depressing side and form an upright crack with the neutral axis of the compressed concrete, whereas in GFRP reinforced concrete beams without concrete cover, failure of shear compression with conditions of deformed reinforcement (bi-linear) with sloping cracks and suddenly spread towards the neutral axis of the compressed concrete so that there was a sudden collapse.

scholarly journals Effect Use of Two Chemical Compounds Sodium Nitrate and Sodium Silicate as Corrosion Inhibitor to Steel Reinforcement

2019 ◽  
Vol 14 (2) ◽  
pp. 123-128
Author(s):  
Sarah Kareem Mohammed
Keyword(s):  
Corrosion Rate ◽  
Sodium Silicate ◽  
Electrolyte Solution ◽  
Sodium Nitrite ◽  
Corrosion Inhibitors ◽  
Sea Water ◽  
Chemical Compounds ◽  
Steel Sample ◽  
Steel Reinforcement ◽  
Corrosion Of Steel

Corrosion of steel reinforcement is one of the biggest problems facing all countries in the world like bridges in the beach area and marine constructions which lead to study these problems and apply some economical solutions. According to the high cost of repair for these constructions, were studied the effect of using kind of chemical compounds sodium nitrite(NaNO2) and sodium silicate(Na2SiO3) as corrosion inhibitors admixture for steel bars that immersed partially in electrolyte solution (water + sodium chloride in 3% conc.) (Approximately similar to the concentration of salt in sea water). The two inhibitors above added each one to the electrolyte solution at concentrations (0.5%, 1% and 2%) for both of them.      The results were  corrosion rate for steel sample that's immersed partially in salt solution was higher than corrosion rate of steel bar that's immersed partially in electrolyte solution with inhibitors  also the two corrosion inhibitors (sodium nitrite and sodium silicate) that added to the electrolyte solution were working successfully to prevent and inhibit the corrosion by using weight loss technique with best percent of 0.5% sodium nitrite ( efficiency 94.1% ) and best percent of 2% sodium silicate ( efficiency 92.5%).

DEVELOPMENT OF EMBEDDED MINI-SENSOR FOR DIAGNOSIS OF CORROSION OF STEEL REINFORCEMENT IN CONCRETE NONDESTRUCTIVELY

2016 ◽  
Vol 3 (2) ◽  
Author(s):  
Mohamed A. Ismail ◽  
Han-Seung Lee ◽  
Mohd Warid Hussin
Keyword(s):  
Reinforced Concrete ◽  
Polarization Resistance ◽  
Concrete Structures ◽  
Steel Reinforcement ◽  
Reinforced Concrete Structures ◽  
Chloride Ingress ◽  
Reinforcement Corrosion ◽  
Maintenance And Rehabilitation ◽  
Corrosion Of Steel ◽  
Non Destructive

Corrosion of steel reinforcement embedded in concrete is one of the main causes of degradation of reinforced concrete structures. Degradation occurs in reinforced concrete structures from corrosion caused by the Chloride ingress into concrete. That degradation has a severe impact on the structure in terms of maintenance and rehabilitation costs. Therefore, early detection of reinforcement corrosion is important for efficient maintenance, repair and planning. Meanwhile, the evaluation of the corrosion of reinforcement by non-destructive measurements have been used a lot. In particular CM-II (corrosion meter) is used to measure the polarization resistance, but has some disadvantages. Embedded mini-sensor has been developed in order to overcome these disadvantages. In this study, measurement of corrosion by using the mini-sensor is compared with the measured results by CM-II to verify the validity of the newly developed mini senor. Results show that there are agreement in trends of the parameters measured and as such the developed mini sensor has a promising start to be used.

scholarly journals THE PROPERTIES OF PITTING CORROSION OF STEEL REINFORCEMENT OF REINFORCED CONCRETE BEAMS

2017 ◽  
Vol 2 (3) ◽  
pp. 32-36
Author(s):  
Дронов ◽  
Andrey Dronov
Keyword(s):  
Reinforced Concrete ◽  
Pitting Corrosion ◽  
Concrete Beams ◽  
Concrete Structures ◽  
Steel Reinforcement ◽  
Reinforced Concrete Beams ◽  
Reinforced Concrete Structures ◽  
Damage Distribution ◽  
Chloride Environment ◽  
Corrosion Of Steel

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.

scholarly journals 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

2016 ◽  
Vol 6 (3) ◽  
pp. 272-283
Author(s):  
Y. Hernández ◽  
O. Troconis de Rincón ◽  
A. Torres ◽  
S. Delgado ◽  
J. Rodríguez ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Corrosion Rate ◽  
Crack Width ◽  
Concrete Beams ◽  
Propagation Rate ◽  
Concrete Cover ◽  
Corrosion Process ◽  
Reinforced Concrete Beams ◽  
Electrochemical Tests ◽  
Rebar Corrosion

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. 

RETROFIT STEEL CORRODING RC BEAMS USING CFRP COMPOSITES: NLFE ANALYSIS

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Rami H. Haddad
Keyword(s):  
Bearing Capacity ◽  
Failure Modes ◽  
Concrete Beams ◽  
Load Capacity ◽  
Concrete Cover ◽  
Cfrp Sheets ◽  
Cfrp Composites ◽  
Severe Reduction ◽  
Corrosion Of Steel ◽  
Repair Techniques

Corrosion of steel reinforcement is one of the main durability problems facing reinforced concrete infrastructures worldwide. Steel degradation and/or cracking of concrete both cause severe reduction in bearing capacity, leading ultimately to failure. The potential of repairing corroded concrete beams with two configurations of carbon-fiber reinforced polymeric (CFRP) composites was investigated with a nonlinear finite Element (NLFE) model. CFRP composites were assumed to be either bonded directly to existing concrete or to a new concrete cover; replacing the old one. The data generated showed that the load-bearing capacity and stiffness for concrete beams, as long as corrosion levels were below 10%, can be fully restored. However, the ductility in terms of deflection at failure would be reduced, especially for repair techniques that involved anchoring with CFRP sheets. For corrosion levels greater than 10%, attaching CFRP composites to a new concrete cover contributed to additional improvements in load capacity and stiffness ranging from 10 to 15% of that achieved from similar repairing on existing concrete. The failure modes indicated that debonding failure prevailed, and that the extent of debonding prior to failure depended upon the corrosion level and on whether the concrete cover was replaced or not.

Reinforcement Corrosion versus Crack Width

2014 ◽  
Vol 897 ◽  
pp. 161-164
Author(s):  
Peter Kotes ◽  
Ján Kozák
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Construction Material ◽  
Steel Reinforcement ◽  
Reinforced Concrete Beams ◽  
Reinforcement Corrosion ◽  
Materials Selection ◽  
Resistant Material ◽  
Corrosion Of Steel ◽  
Design Construction

Reinforced concrete is a versatile, economical and successful construction material. Usually, it is durable and resistant material, performing well throughout its service life. However, sometimes it does not perform adequately as it is expected. It is due to poor design, construction, inadequate materials selection and more severe environment than anticipated or a combination of those factors [1, . The reinforcement corrosion is the phenomenon that highly affects the reliability and durability of reinforced concrete structures. From that reason, a lot of researchers in Slovakia and in the world pay their attention to reinforcement corrosion. The paper is concerned with detection and simulation of corrosion of steel reinforcement in the reinforced concrete. The cracking response of the reinforced concrete beams due to the corrosion effect of the steel reinforcement was analyzed. The effect of corrosion was simulated by the nonlinear numerical analysis using the program ATENA.

scholarly journals Analysis of the corrosion behavior of steel reinforcement protected by phosphate coatings

2020 ◽  
Vol 329 ◽  
pp. 02001
Author(s):  
Viktoriya Konovalova
Keyword(s):  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Electrochemical Corrosion ◽  
Chloride Ions ◽  
Steel Reinforcement ◽  
Protective Properties ◽  
Phosphate Coatings ◽  
Additional Protection ◽  
Corrosion Of Steel ◽  
Kinetics Of

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.

The Corrosion of Steel Reinforcement in Carbonated Concrete Under Different Humidity Regimes

1994 ◽  
Vol 370 ◽  
Author(s):  
Anastasia G. Constantinou ◽  
Karen L. Scrivener
Keyword(s):  
Corrosion Rate ◽  
Concrete Cover ◽  
Interfacial Region ◽  
Reinforcing Bars ◽  
Electrochemical Monitoring ◽  
Corrosion Of Steel ◽  
Curing Regimes ◽  
Linear Polarisation ◽  
Concrete Interface ◽  
Microstructural Examination

AbstractIn this investigation, four concretes (two mix designs and two curing regimes), containing reinforcing bars at covers 11 mm and 20 mm were carbonated fully in 100% CO2 and 65% relative humidity (RH). They were then placed in two different humidity environments (65% RH and 90% RH). The progress of the corrosion of the samples was followed electrochemically (using the linear polarisation technique) and microscopically (using a scanning electron microscope).Electrochemical monitoring of the corrosion rate showed that corrosion started very soon after placement in the humidity regimes and generally increased with time. The water/cement ratio, the concrete cover of the reinforcement and the curing of the concrete had a significant effect the length of time taken to carbonate the specimens. However, the effect of these variables on the corrosion rate was negligible. In addition, the corrosion rate showed no dependance on the humidity regimes.Microstructural examination of the samples revealed the existence of corrosion products at the steel/concrete interface after 6 months in the humidity regimes. There was more corrosion product in the samples at 90% RH. The samples with the low w/c showed more extensive cracking in the interfacial region.

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