Numerical model for corrosion rate of steel reinforcement in cracked reinforced concrete structure

Electrochemical chloride extraction – ECE is an effective method to rehabilitate reinforced concrete structure, which has been corroded. This study investigated concentration of chloride remained in concrete and half-cell potential of the steel reinforcement after ECE using interrupting period of electricity current. Efficiency of ECE using Ca (OH)2was surveyed with two current density of 0.5 and 1A/m2. In this study, ECE treatment was proceeded intermittently in approximately 8 weeks. Results pointed out that chloride concentration decreased to 30 – 60% significantly, especially at in the vicinity of reinforcing steel. Simultaneously, half-cell potential of the steel reinforcement after 4 weeks halted treatment stabilizes in low-corrosion rate.

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Test and Study on Impact of Corrosion on Bond Force between Steel and Concrete

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.36.176 ◽

2010 ◽

Vol 36 ◽

pp. 176-181

Author(s):

Xian Feng He ◽

Shou Gang Zhao ◽

Yuan Bao Leng

Keyword(s):

Reinforced Concrete ◽

Corrosion Rate ◽

Concrete Structure ◽

Steel Corrosion ◽

Reinforced Concrete Structure ◽

Bond Force ◽

Steel Bars ◽

Protection Layer ◽

Corrosion Of Steel ◽

The Impact

The corrosion of steel will have a bad impact on the safety of reinforced concrete structure. In severe cases, it may even be disastrous. In order to understand the impact of steel corrosion on the structure, tests are carried out to study corrosion and expansion rules of steel bars as well as the impact rules of corrosion on bond force between steel and concrete. The results show that wet and salty environment will result in steel corrosion; relatively minor corrosion will not cause expansion cracks of protection layers; when steel rust to a certain extent, it will cause cracks along the protection layer; when there exists minor corrosion in steel and the protection layer does not have expansion cracks, the bond force is still large and rapidly decreases as the corrosion rate increases.

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Corrosion Risk of Reinforced Concrete Structure Arising from Internal and External Chloride

Advances in Materials Science and Engineering ◽

10.1155/2018/7539349 ◽

2018 ◽

Vol 2018 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

M. J. Kim ◽

K. Y. Ann

Keyword(s):

Reinforced Concrete ◽

Corrosion Rate ◽

Concrete Structure ◽

Threshold Level ◽

Exposure Condition ◽

Reinforced Concrete Structure ◽

Galvanic Current ◽

Corrosion Risk ◽

Wet Condition ◽

Cathode Metal

The corrosion risk of internal chloride and external chloride from three different exposure conditions was evaluated. The initiation of corrosion was detected by monitoring the galvanic current between cathode metal and embedded steel. The chloride threshold was determined by measuring the corrosion rate of steel by the polarization technique for internal chloride and the chloride profiling test for external chloride. As the result, the initiation of corrosion was accelerated with a cyclic wet/dry condition, compared to the totally wet condition. In addition, it was found that an increase of the drying ratio in the exposure condition resulted in an increase of corrosion rate after initiation. The threshold level of external chloride ranged from 0.2 to 0.3% weight by cement and internal chloride shows higher range, equated to 1.59–3.10%. Based on these data, the chloride penetration with exposure condition was predicted to determine the service life of reinforced concrete structure.

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Alternative methodology for linear polarization resistance assessment of reinforced concrete structure

MATEC Web of Conferences ◽

10.1051/matecconf/201819906009 ◽

2018 ◽

Vol 199 ◽

pp. 06009 ◽

Cited By ~ 1

Author(s):

Gabriel Samson ◽

Fabrice Deby ◽

Jean-Luc Garciaz ◽

Jean-Louis Perrin

Keyword(s):

Reinforced Concrete ◽

Corrosion Rate ◽

Current Density ◽

Linear Polarization ◽

Concrete Structure ◽

Polarization Resistance ◽

Concrete Cover ◽

Reinforced Concrete Structure ◽

Linear Polarization Resistance ◽

Steel Rebar

For reinforced concrete structures, several corrosion detection methods exist: concrete resistivity, half-cell potential or linear polarization resistance (LPR) measurement. The LPR value can be linked to the corrosion rate thanks the Stern-Geary equation if strong hypotheses are made. Existing commercial devices use a guard ring to canalize the current on specific steel rebar area and assume that the steel rebar is uniformly polarized. However, recent works reveal that the top part of the steel rebar, right under the counter electrode, is the most polarized point. The particular point is referred as the point of interest (PI). This works belongs to the DIAMOND project which aims to produce a new corrosion rate measurement device. Comsol® software was used to model the influence of concrete cover, resistivity and injected current on the current density at the PI. Moreover, a significant influence of the steel rebars diameter was also demonstrated. Two types of abacus are built. The first one links to polarization measured on the surface to the polarization on the rebar at the PI. The second links the ratio between the current density at the PI and the density of injected current to concrete cover and steel rebar diameter. The Stern-Geary equation can now be used at the PI without using the approximation of a uniformly polarized rebar. The corrosion state of reinforced concrete structure can be controlled more precisely. The methodology is then applied on two concrete slabs in which three metal bars are embedded at different concrete covers. The first slab is prepared with ordinary concrete while the second contain chloride to artificially activate the corrosion process. The results reveal that the rebars embedded on the first slab are not corroding (icorr ≤0.2 μΑ/cm2) while the second rebar are corroding (icorr>0.2 μΑ/cm2).

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Analysis of different interface treatments between masonry of AAC blocks and reinforced concrete structure after uniaxial compression strength test

Materiales de Construcción ◽

10.3989/mc.2021.09920 ◽

2021 ◽

Vol 71 (343) ◽

pp. e252

Author(s):

D.S. Silva ◽

E.G.P. Antunes

Keyword(s):

Reinforced Concrete ◽

Uniaxial Compression ◽

Concrete Structure ◽

Load Capacity ◽

Maximum Load ◽

Steel Reinforcement ◽

Reinforced Concrete Structure ◽

Uniaxial Compression Strength ◽

Compression Resistance ◽

Interface Treatment

Autoclaved aerated concrete (AAC) masonry is widely used in civil construction but requires further investigation. Hence, this experimental study evaluated three types of interface treatment between the reinforced concrete structure and AAC masonry, in scale, after a uniaxial compression resistance test. The types of interface treatment considered are reinforcement with steel bars, with rough polymeric cementitious mortar, and without treatment. The maximum load capacity, displacements, and occurrence of cracks were analysed. The results showed that the maximum individual load capacity did not significantly differ among the examined groups. However, the analysis of the displacements and cracks showed that the group with steel reinforcement had the smallest displacements and largest cracks. This behaviour is owing to the greater solidarity of forces conferred by steel reinforcement.

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The Concrete Structure Strengthen Technology and Engineering Application

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.194-196.835 ◽

2011 ◽

Vol 194-196 ◽

pp. 835-839

Author(s):

Jun Hong Li

Keyword(s):

Reinforced Concrete ◽

Cross Section ◽

Concrete Structure ◽

Engineering Application ◽

Steel Reinforcement ◽

Reinforced Concrete Structure ◽

Fiber Reinforced Plastic ◽

Advantages And Disadvantages ◽

Reinforced Plastic ◽

Concrete Reinforcement

In this paper, the background of concrete structure strengthen is described, and several common methods of strengthening concrete structure in current construction are introduced. Also the advantages and disadvantages application of reinforcement methods are discussed. so as to valuable experiences for strengthening reinforced concrete structures are accumulate. Both the advantages and disadvantages of the reinforcement methods are described in detail. For example, the increasing cross-section reinforcement method, the replacing concrete reinforcement method, the bonding steel reinforcement method, the pasting steel reinforcement method, the pasting fiber reinforced plastic reinforcement method and so on. And so many accumulated experiences are provided for later strengthening reinforced concrete structure, and the process of strengthening concrete structure is improved.

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Experimental Study of Corrosion Sensors for the Design Technology of Bridge Longevity

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.597.421 ◽

2014 ◽

Vol 597 ◽

pp. 421-424

Author(s):

Jin A Jeong

Keyword(s):

Reinforced Concrete ◽

Concrete Structure ◽

Corrosion Potential ◽

Steel Corrosion ◽

Chloride Content ◽

Steel Reinforcement ◽

Reinforcement Corrosion ◽

Reinforced Concrete Structure ◽

Corrosion Condition ◽

Potential Measurement

Corrosion of steel reinforcement is a major factor in the deterioration of harbor and bridge structure. Steel corrosion in concrete must be checked for investigating the condition of a reinforced concrete structure. The several way how to measuring corrosion condition of reinforced concrete, but the corrosion potential measurement is a very simple, rapid, cost-effective and non-destructive technique to evaluate the severity of corrosion in reinforced concrete structure. However some particular situations may not relate to the reinforcement corrosion probability and a simple comparison of the corrosion potential data with the ASTM Standard on steel reinforcement corrosion probability could prove meaningless because of environment factors as oxygen concentration, chloride content, the concrete resistance. Therefore this paper proposed compact designed corrosion sensors to monitor several corrosion factors, and the electrochemical measurement and evaluation have been carried out to investigate rebar corrosion, and a reasonable prediction of corrosion has been obtained in terms of nondestructive electrochemical point of view.

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PENGARUH DENSITAS ARUS TERHADAP PERILAKU RETAK BETON BERTULANG YANG MENGALAMI KOROSI TULANGAN

Teras Jurnal ◽

10.29103/tj.v11i2.507 ◽

2021 ◽

Vol 11 (2) ◽

pp. 351

Author(s):

Zahra Amalia ◽

Taufiq Saidi ◽

Teuku Budi Aulia ◽

...

Keyword(s):

Reinforced Concrete ◽

Corrosion Rate ◽

Current Density ◽

Concrete Structure ◽

Corrosion Products ◽

Reinforced Concrete Structure ◽

Accelerated Corrosion ◽

Cracking Behavior ◽

Cross Section Area ◽

Lower Corrosion Rate

Abstrak Korosi pada struktur beton betulang dapat mengurangi kinerja struktur dan umur layannya karena volume tulangan yang berkurang. Besarnya jumlah korosi yang dipengaruhi oleh laju korosi dapat digambarkan melalui besarnya densitas arus yang terjadi. Jumlah korosi yang terjadi mempengaruhi perilaku retak pada beton bertulang, oleh karen itu, pada studi ini dilakukan uji eksperimental untuk mengevaluasi pengaruh densitas arus terhadap perilaku retak permukaan beton dari struktur beton bertulang yang mengalami korosi tulangan. Pengujian dilakukan dengan mengaplikasikan variasi densitas arus yaitu 900 µA/cm2, 500 µA/cm2, 200 µA/cm2 and 100 µA/cm2 pada pengujian korosi secara elektrik menggunakan larutan NaCl sebagai elektrolit untuk menghasilkan ion Cl-. Benda uji yang digunakan adalah balok dengan luas penampang 150x150 mm2 dan panjang benda uji 300 mm. Tulangan baja diameter 19 mm digunakan pada tengah penampang. Hasil pengujian menunjukkan bahwa perilaku retak dari beton bertulang yang mengalami korosi pada tulangannya memiliki kurva yang bilinear. Selain itu, hasil pengujian menunjukkan bahwa densitas arus yang rendah memiliki kecepatan retak permukaan beton yang lebih tinggi jika dibandingkan dengan benda uji dengan menggunakan densitas arus yang tinggi. Kata kunci: korosi, beton bertulang, produk korosi, retak, densitas arus Abstract Corrosion in reinforced concrete structure can reduce structure performance and its service life due to rebar mass loss. Corrosion amount influenced by corrosion rate can be figured out by using current density. Corrosion amount influences the crack behavior of reinforced concrete, therefore, in this study, experimental study was performed to evaluate the effect of current density to surface concrete cracking behavior of corroded reinforced concrete structure. Accelerated corrosion test tests were conducted with various current density. It was 900 µA/cm2, 500 µA/cm2, 200 µA/cm2 and 100 µA/cm2. NaCl solution was used as electrolyte to produce ion Cl-. The specimens were beam with cross section area 150x150 mm2 and 300 mm in length. Rebar with diameter 19 mm was applied in the center of specimen. The results showed that cracking behavior of corroded rebar has bilinear curve that shows the effect of corrosion products movement through cracks. Furthermore, lower corrosion rate has higher cracking speed than higher corrosion rate. Keywords: corrosion, reinforced concrete, corrosion products, cracking, current density

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