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

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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Effect of Interrupting Electricity Period on Electrochemical Chloride Extraction of Reinforced Concrete

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.754-755.342 ◽

2015 ◽

Vol 754-755 ◽

pp. 342-347

Author(s):

Mien Van Tran ◽

Dong Viet Phuong Tran ◽

Mohd Mustafa Al Bakri Abdullah

Keyword(s):

Reinforced Concrete ◽

Corrosion Rate ◽

Current Density ◽

Concrete Structure ◽

Chloride Concentration ◽

Steel Reinforcement ◽

Reinforced Concrete Structure ◽

Half Cell ◽

Cell Potential ◽

Electrochemical Chloride Extraction

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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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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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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Galvanic Corrosion between Depleted Uranium and 45 Steel

Materials Science Forum ◽

10.4028/www.scientific.net/msf.749.606 ◽

2013 ◽

Vol 749 ◽

pp. 606-610 ◽

Cited By ~ 1

Author(s):

Zhen Pu ◽

Qing Fu Wang ◽

Mao Bin Shuai ◽

Ding Mu Lang

Keyword(s):

Corrosion Rate ◽

Current Density ◽

Energy Dispersive Spectroscopy ◽

Galvanic Corrosion ◽

Depleted Uranium ◽

Corrosion Products ◽

Energy Dispersive ◽

Nacl Solution ◽

Accelerated Corrosion

Self-corrosion and galvanic corrosion of depleted uranium and 45 steel were studied by electrochemical analyzing technologies. Corrosion products were analyzed by Energy-dispersive spectroscopy (EDS). The results showed that, in the 3.5wt.%NaCl solution, DU acted as anode with an accelerated corrosion rate, and 45 steel acted as cathode during the process of galvanic corrosion for DU/45 couple. The galvanic potential and current density of the DU/45 couple were around-770mV and 12.5μA/cm-2, respectively.

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The Study of Half-cell Potential Behaviour of Reinforced Concrete in Marine Environment

International Journal for Research in Applied Science and Engineering Technology ◽

10.22214/ijraset.2021.36265 ◽

2021 ◽

Vol 9 (VII) ◽

pp. 128-131

Author(s):

Shrabanee Giri

Keyword(s):

Reinforced Concrete ◽

Marine Environment ◽

Concrete Structure ◽

Corrosion Test ◽

Reinforced Concrete Structure ◽

Half Cell ◽

Cell Potential ◽

Accelerated Corrosion ◽

Accelerated Corrosion Test ◽

Potential Test

Corrosion of reinforcement in concrete affects the strength and durability of reinforced concrete structure. Monitoring and maintenance of concrete structure throughout the service life prevent the ingress of corrosion at the initial stage. Half-cell potential meter was developed and fabricated to monitor the corrosion potential of reinforcement in a M25 grade concrete. Half-cell potential test and accelerated corrosion test has been carried out in marine environment of 3.5% of NaCl solution. The potential behaviour of specimen subjected to accelerated corrosion is studied throughout the test period. The results were obtained in terms of current flow behaviour and weight loss. Obtained results has been analyzed graphically and a comparative analysis has been carried out to know the rate of corrosion occurred in the specimen by accelerated corrosion test and half-cell potential test. Obtained results clearly indicates that the potential behaviour value increases with increase in time from 160 mV on day 1 to 949 mV on day 5. In the other way the compressive strength value for corroded specimen is lesser than the controlled specimen subjected to accelerated corrosion.

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Review on Effect of Corrosion on Flexure, Shear and Torsional Strength of Reinforced Concrete Beam

International Journal of Scientific Research in Science and Technology ◽

10.32628/ijsrst207317 ◽

2020 ◽

pp. 87-91

Author(s):

Abhinav Chouhan ◽

Nikhil Pitale

Keyword(s):

Reinforced Concrete ◽

Concrete Structure ◽

Construction Materials ◽

Reinforced Concrete Beam ◽

Reinforced Concrete Beams ◽

Reinforced Concrete Structure ◽

Accelerated Corrosion ◽

Torsional Strength ◽

Ductile Behavior ◽

Moment Of Resistance

With the increase in demand for construction materials, man has improved a lot in the construction techniques of structures. Reinforced concrete beams are normally designed as under reinforced to provide ductile behavior such as the tensile moment of resistance. In coastal environment reinforcement corrosion is an obvious cause of deterioration of concrete structure, which affects the durability and service of reinforced concrete structure. Structural stability is majorly influenced by strength of concrete. Torsional strength is a measure of the shear strength of concrete, in other words it is a measure of a resistance against failure in twisting. The main aim of this study is to analyze the flexural, shear & torsional strength, experimentally; of corroded beams using Ordinary Portland cement. Accelerated corrosion technique was adopted to corrode the beam experimentally. We have used varying percentage of corrosion as 0%, 2.5%, 5% and 7.5%. Change in strength of RC beams is studied for varying percentage of corrosion. Beam specimens are prepared using M20 grade concrete for OPC. Beam specimens casted are tested in UTM for flexure and shear. Specially prepared loading setup is used for torsional strength test.

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A Study on Cathodic Protection Current Density on Rebar in Onshore Concrete Structure of Persian Gulf

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.850-851.270 ◽

2013 ◽

Vol 850-851 ◽

pp. 270-273

Author(s):

Ya Ping Wang ◽

Da Jing Fang ◽

Jun Huang ◽

Er Bu Shen

Keyword(s):

Reinforced Concrete ◽

Current Density ◽

Cathodic Protection ◽

Persian Gulf ◽

Concrete Structure ◽

Reinforced Concrete Structure ◽

Marine Corrosion ◽

Impressed Current ◽

Corrosion Of Steel ◽

Control Corrosion

The service life of reinforced concrete structure has been greatly influenced by corrosion of steel, however, impressed current cathodic protection (ICCP) system is able to control corrosion of steel, especially which is corroded by chloride along the coast areas. In this work protection current and related technical parameter in both intake and outfall structure has been investigated in the seawater cooling structure along the coast area of Persian Gulf in Saudi Arabia. The most suitable protection current density provided by ICCP system is 5mA/m2for reinforced concrete structure in the severe marine corrosion area in Middle East.

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