Corrosion Characteristics of Reinforced Steel Bar Emedded in Mortar Specimen(W/C:0.4) Aged 5 Years in Seawater

2013 ◽  
Vol 753-755 ◽  
pp. 776-783
Author(s):  
Kyung Man Moon ◽  
Jong Pil Won ◽  
Dong Hyun Park ◽  
Myeong Hoon Lee ◽  
Yun Hae Kim
Keyword(s):  
Steel Surface ◽  
Sea Water ◽  
Chloride Ion ◽  
Cyclic Voltammograms ◽  
Corrosion Properties ◽  
Economic Point ◽  
Mortar Specimen ◽  
Steel Bar ◽  
Reinforced Steel ◽  
Cover Thickness

Reinforced concrete structures have been increasingly widely used in numerous industrial fields. These structures are often exposed to severely corrosive environments such as sea water, contaminated water, acid rain, and the seashore. Thus, corrosion problems of the steel bars embedded in concrete are very important from a safety and economic point of view. In this study, the effects of cover thickness on the corrosion properties of reinforced steel bar embedded in mortar specimen were investigated using electrochemical methods such as corrosion potentials, polarization curves, cyclic voltammograms, galvanostat and potentiostat. Corrosion potentials shifted in the noble direction, and the value of AC impedance also exhibited a higher value with decreasing cover thickness, furthermore, polarization resistance also increased with decreasing cover thickness. This is probably that the thinner cover thickness, it is easy for the dissolved oxygen and chloride ion to intrude and diffuse to the steel bar, thereby making it easier to corrode on the steel surface compared to thicker cover thickness, which is resulted in forming the corrosive products on the steel surface. Therefore, it is considered that the corrosive products plays a role to provide nobler value of corrosion potential and higher value of impedance. Consequently, it seems that the corrosion resistance of inner steel bar may depend on mainly not cover thickness but the resistance polarization due to corrosive products in the case of immerged for 5 years in this experiment.

The Effect of Cover Thickness to Corrosion Characteristics of Reinforced Steel Bar Emedded in Mortar Specimen (W/C:0.6) Aged 5 Years in Seawater

2013 ◽  
Vol 785-786 ◽  
pp. 1176-1180 ◽  
Author(s):  
Sung Yul Lee ◽  
Jong Pil Won ◽  
Dong Hyun Park ◽  
Myeong Hoon Lee ◽  
Kyung Man Moon
Keyword(s):  
Corrosion Resistance ◽  
Polarization Resistance ◽  
Corrosion Potential ◽  
Polarization Curves ◽  
Cyclic Voltammograms ◽  
Economic Point ◽  
Mortar Specimen ◽  
Steel Bar ◽  
Reinforced Steel ◽  
Cover Thickness

Reinforced concrete structures have been increasingly widely used through numerous industrial fields. These structures are often exposed to severely corrosive environments such as sea water, contaminated water, acid rain, and the seashore. Thus, corrosion problems of the steel bars embedded in concrete are very important from a safety and economic point of view. In this study, the effects of cover thickness on the corrosion properties of reinforced steel bar embedded in mortar specimen (W/C:0.6) were investigated using electrochemical methods such as corrosion potentials, polarization curves, cyclic voltammograms, galvanostat and potentiostat. Corrosion potentials shifted to the noble direction, and the value of AC impedance also exhibited a higher value with increasing cover thickness, furthermore, polarization resistance also increased with increasing cover thickness. This is probably that the thinner cover thickness, seawater solution is easy to arrive at embedded steel compared to other thicker cover thickness, so, its steel bar may be easily corroded due to chloride ion, which is resulted in shifting corrosion potential to negative direction, decreasing polarization resistance. Consequently, it is considered that the relation between corrosion resistance of reinforced steel and cover thickness is nearly matched with each other. However, its corrosion resistance estimated by measurement of corrosion potential was not well in agreement with value obtained by polarization curves.

Evaluation on the Addition of Inhibitor and Surface Treatment to Corrosion Behavior of the Reinforced Steel Bar Embedded in Mortar Specimen

2017 ◽  
Vol 744 ◽  
pp. 114-120
Author(s):  
Kyung Man Moon ◽  
Sung Yul Lee ◽  
Jae Hyun Jeong ◽  
Myeong Hoon Lee
Keyword(s):  
Current Density ◽  
Test Specimen ◽  
Corrosion Current Density ◽  
Corrosion Current ◽  
Corrosion Properties ◽  
Mortar Specimen ◽  
Steel Bar ◽  
Steel Bars ◽  
Reinforced Steel ◽  
One Year

In this study, seven types of mortar test specimens were manufactured with parameters, that is, the surface of the reinforced steel bar was treated with hot dip galvanizing (Zn) and the surface of the test specimen was coated with underwater paint, and four types of inhibitors (DAW, MCI, DCI, and Silcon) were added in mortars respectively. And, the seven types of mortar test specimens were immersed in seawater for 4 years. The corrosion properties of the reinforced steel bars embedded in mortar test specimens were investigated using electrochemical methods. The corrosion potentials of the test specimens with painting on the surface of the specimen and Zn coating on the surface of the steel bar exhibited the noblest and lowest values respectively after one year, however, after 4 years, the specimens of underwater painting and of addition of Silcon inhibitor indicated the noblest and lowest values of corrosion potentials respectively. Furthermore, the painting specimen exhibited the smallest values of corrosion probability as welll as of the corrosion current density, while, addition of MCI inhibitor showed the highest values of both corrosion probability and corrosion current density. Moreover, the painting specimen showed the smallest value of neutralization degree among all the specimens, and the largest value of neutralization degree was observed at the specimen of natural condition (no adding of inhibitor, no painting and no Zn coating). As a result, it is considered that the addition of inhibitors, coating with hot dip galvanizing (Zn), and painting on the surface have the effects not only to inhibit the neutralization degree but also to increase the corrosion resistance of the embedded steel bar.

Coating Thickness of Reinforced Concrete Affecting to Cathodic Polarization and Cyclic Voltammogram of Reinforced Steel

2016 ◽  
Vol 723 ◽  
pp. 741-747
Author(s):  
Kyung Man Moon ◽  
Sung Yul Lee ◽  
Jae Hyun Jeong ◽  
Myeong Hoon Lee
Keyword(s):  
Current Density ◽  
Coating Thickness ◽  
Corrosion Current Density ◽  
Cathodic Polarization ◽  
Sea Water ◽  
Corrosion Current ◽  
Corrosion Products ◽  
Cyclic Voltammogram ◽  
Steel Bar ◽  
Reinforced Steel

The reinforced concretes are often exposed to severely corrosive environments such as sea water, contaminated water, acid rain and seashore etc.. Therefore, the reinforced steel bar embedded in the concrete is increasingly corroded in various environments mentioned above, and this corrosion problem is thought to be very important in terms of the safety and economic points of view. In this study, a multiple mortar test specimen(W/C:0.5) with variation of coating thickness was prepared and immerged in flowing seawater for five years. And, the effects of coating thickness affecting to cathodic polarization and cyclic voltammogram were investigated using electrochemical methods. The thinner coating thickness, both invasion and diffusion of dissolved oxygen, water and chloride ion on the surface of reinforced steel bar is more easily compared to the thicker coating thickness. Thus, at the beginning of immersion, the rate of corrosion in the case of the thinner coating thickness is higher than that of the thicker coating thickness. However, it is considered that corrosion products deposited on the surface due to higher corrosion rate played the role as a resistance polarization, and increased the diffusion layer, as a result, decreased the corrosion current density compared to the thicker coating thickness. Consequently, the relationship between corrosion current density and the coating thickness were not well in good agreement with each other due to the corrosion products after being immersed for 5 years. Therefore, in order to more optimum evaluate for corrosion possibility of the reinforced steel embedded in the concrete, not only corrosion potential but also other parameters such as coating thickness, W/C ratio, and other corrosion environment should be investigated in the case of immersed in seawater for long years.

scholarly journals Corrosion Characteristics of Reinforced Steel Bar Emedded in Multiple Mortar Specimen(W/C:0.5) Aged 5 Years in Seawater

2013 ◽  
Vol 3 (1) ◽  
pp. 33-37
Author(s):  
Kyung-Man Moon ◽  
Oki Takeo ◽  
Jong-Pil Won ◽  
Dong-Hyun Park ◽  
Yun-Hae Kim
Keyword(s):  
Mortar Specimen ◽  
Steel Bar ◽  
Reinforced Steel

Passing Aged Years to Polarization Characteristics of the Steel Bar Embedded in Mortar Specimen (W/C:0.4)

2013 ◽  
Vol 821-822 ◽  
pp. 1227-1231
Author(s):  
Sung Yul Lee ◽  
Jong Pil Won ◽  
Dong Hyun Park ◽  
Jae Hyun Jeong ◽  
Kyung Man Moon
Keyword(s):  
Polarization Curve ◽  
Anodic Polarization ◽  
Corrosion Potential ◽  
Anodic Polarization Curve ◽  
Industrial Society ◽  
Positive Direction ◽  
Potential Measurement ◽  
Mortar Specimen ◽  
Steel Bar ◽  
Cover Thickness

The structures of reinforced concrete has been extensively increased with rapid development of industrial society. Furthermore, these reinforced concretes are often exposed to severely corrosive environments such as sea water, contaminated water, acid rain and seashore etc.. Thus, the corrosion problem of a steel bar embedded in the concrete is very important in terms of the safety and economic points of view. In this study, a multiple mortar test specimen (W/C:0.4) that had six types of cover thickness was prepared and immerged in flowing seawater for five years. And the effects of cover thickness and immersion years on the corrosion properties of the steel bars were investigated using electrochemical methods such as measuring corrosion potential, anodic polarization curve, and impedance. At the beginning of immersion (0 year), corrosion potentials exhibited increasingly nobler value with increasing the cover thickness. However, after being immersed for 5 years, the corrosion potentials conversely shifted in the positive direction with decreasing the cover thickness. As a result, the relationships between corrosion potential and cover thickness were not in good agreement with each other after 5 years. In addition, after 5 years, the thinner cover thickness, the higher value of impedance at 0.01Hz. It is considered that corrosive products deposited on the surface of the steel bar embedded in mortar specimen in the case of thinner cover thickness played the role as a resistance polarization which resulted in decreasing the corrosion current density. Consequently, it seemed to be somewhat problem that evaluation on the corrosion property in reinforced steel would be estimated by only the corrosion potential measurement. Therefore, it is suggested that we should take into account various parameters such as cover thickness, corrosion potential, and immersed years etc. for its accurate assessment. Keywords : Cover thickness, Corrosion potential, Anodic polarization curve, Impedance, Resistance polarization

The Fabrication of Self-Assembled Film on Steel Surface

2013 ◽  
Vol 364 ◽  
pp. 674-678
Author(s):  
Ze Min Chen ◽  
Xue Chao Jiao ◽  
Xuan Zhou ◽  
Su Hong Wang
Keyword(s):  
Citric Acid ◽  
Boric Acid ◽  
Silane Coupling Agent ◽  
Steel Surface ◽  
Sea Water ◽  
Orthogonal Experiment ◽  
Analysis Experiment ◽  
Silane Coupling ◽  
Single Factor Analysis ◽  
Self Assembled

Fabrication of self-assembled film used 792(silane coupling agent), citric acid, boric acid and triethanolamine as the main materials. Through orthogonal experiment and the single factor analysis experiment, the optimum technological conditions are 792 10mL·L-1, citric acid 24g·L-1, boric acid 8g·L-1, triethanolamine 7.5mL·L-1, temperature 20~21°C, time 10min. Simulated sea water (3% Sodium chloride) is applied to measure the effects of the film. The results show that the processing is simple, tank liquor is stable, and film is uniform, dense and colorless.

Impalement with Spinal Cord Injury Requiring Intraoperative Division of a Reinforced Steel Bar

2005 ◽  
Vol 31 (5) ◽  
pp. 503-507 ◽  
Author(s):  
Madison Macht ◽  
Adnan Rizvi ◽  
Martin A. Schreiber ◽  
W. Slate Wilson
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Steel Bar ◽  
Cord Injury ◽  
Reinforced Steel

Osmoregulation in the Larva of the Marine Caddis Fly, Philanisus Plebeius (Walk.) (Trichoptera)

1972 ◽  
Vol 57 (3) ◽  
pp. 821-838
Author(s):  
JOHN P. LEADER
Keyword(s):  
Sodium Chloride ◽  
Osmotic Pressure ◽  
Body Surface ◽  
Sea Water ◽  
Electrical Potential ◽  
Chloride Ion ◽  
Chloride Ions ◽  
The Body ◽  
Electrical Potential Difference ◽  
Caddis Fly

1. The larva of Philanisus plebeius is capable of surviving for at least 10 days in external salt concentrations from 90 mM/l sodium chloride (about 15 % sea water) to 900 mM/l sodium chloride (about 150 % sea water). 2. Over this range the osmotic pressure and the sodium and chloride ion concentrations of the haemolymph are strongly regulated. The osmotic pressure of the midgut fluid and rectal fluid is also strongly regulated. 3. The body surface of the larva is highly permeable to water and sodium ions. 4. In sea water the larva is exposed to a large osmotic flow of water outwards across the body surface. This loss is replaced by drinking the medium. 5. The rectal fluid of larvae in sea water, although hyperosmotic to the haemolymph, is hypo-osmotic to the medium, making it necessary to postulate an extra-renal site of salt excretion. 6. Measurements of electrical potential difference across the body wall of the larva suggest that in sea water this tissue actively transports sodium and chloride ions out of the body.

Development of polyurethane-based superhydrophobic coatings on steel surfaces

2020 ◽  
Vol 378 (2167) ◽  
pp. 20190446 ◽  
Author(s):  
Mukesh Kumar Meena ◽  
Balraj Krishnan Tudu ◽  
Aditya Kumar ◽  
Bharat Bhushan
Keyword(s):  
Contact Angle ◽  
Steel Surface ◽  
Mechanical Stability ◽  
Industrial Applications ◽  
Angle Measurement ◽  
Coated Steel ◽  
Corrosion Properties ◽  
Static Contact ◽  
Steel Surfaces ◽  
Self Cleaning

In this study, a superhydrophobic coating on steel surface has been developed with polyurethane, SiO 2 nanoparticles and hexadecyltrimethoxysilane by using a spin-coating technique. Characterization of the coated steel surface was done by using the contact angle measurement technique, scanning electron microscopy and Fourier transform infrared spectroscopy. With a water tilt angle of 4° ± 2° and static contact angle of 165° ± 5°, the coated surface shows a superhydrophobic and self-cleaning nature. Chemical, thermal, mechanical stability tests and droplet dynamic studies were done to evaluate performance of the coating. Excellent self-cleaning, anti-fogging and anti-corrosion properties of coated steel surfaces make them ideal for industrial applications. This article is part of the theme issue ‘Bioinspired materials and surfaces for green science and technology (part 3)’.

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