Study on the Mechanism of Rebar Corrosion Considering the Relationship between Corrosion and Crack Width

2007 ◽  
Vol 348-349 ◽  
pp. 481-484
Author(s):  
Jei Jun You ◽  
Han Seung Lee ◽  
Yoshiteru Ohno
Keyword(s):  
Stainless Steel ◽  
Crack Width ◽  
Corrosion Current ◽  
Reinforcement Corrosion ◽  
Accelerated Carbonation ◽  
Accelerated Corrosion ◽  
Cement Ratio ◽  
Accelerated Corrosion Tests ◽  
Rebar Corrosion ◽  
The Relationship

In this study, accelerated corrosion tests were conducted on concrete specimens with and without accelerated carbonation beforehand for the purpose of elucidating the effects of carbonation, cover depth, and water-cement ratio (W/C) on the reinforcement corrosion. During testing, the corrosion current between the anode steel and cathode stainless steel was measured to continuously monitor the progress of corrosion throughout the test period, thereby investigating the mechanism of reinforcement corrosion and the relationship between corrosion and crack width, as well as other parameters.

Effect of mechanical restraint on the rate of corrosion in concrete

1998 ◽  
Vol 25 (1) ◽  
pp. 81-86 ◽  
Author(s):  
N Hearn ◽  
J Aiello
Keyword(s):  
Mix Design ◽  
Concrete Repair ◽  
Accelerated Corrosion ◽  
One Dimensional ◽  
Mechanical Restraint ◽  
Corrosion Rates ◽  
Accelerated Corrosion Tests ◽  
The Matrix ◽  
The Relationship

Experimental work on prismatic concrete specimens was conducted to determine the relationship between mechanical restraint and the rate of corrosion. The current together with the changes in strain of the confining frame were monitored during the accelerated corrosion tests. The effect of mix design and cracking on the corrosion rates was also investigated. The results show that one-dimensional mechanical restraint retards the corrosion process, as indicated by the reduction in the steel loss. Improved quality of the matrix, with and without cracking, reduces the rate of steel loss. In the inferior quality concrete, the effect of cracking on the corrosion rate is minimal.Key words: corrosion, concrete, repair.

scholarly journals Concrete Corrosion Cracking and Transverse Bar Strain Behavior in a Reinforced Concrete Column under Simulated Marine Conditions

2020 ◽  
Vol 10 (5) ◽  
pp. 1794 ◽  
Author(s):  
Gyeongcheol Choe ◽  
Yasuji Shinohara ◽  
Gyuyong Kim ◽  
Sangkyu Lee ◽  
Euibae Lee ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Concrete Cover ◽  
Corrosion Cracking ◽  
Reinforced Concrete Column ◽  
Accelerated Corrosion ◽  
Corrosion Tests ◽  
Strain Behavior ◽  
Accelerated Corrosion Tests ◽  
In Situ Conditions ◽  
Rebar Corrosion

This study performed accelerated corrosion tests on reinforced concrete (RC) specimens reinforced with transverse steel bars to evaluate the concrete cracking and rebar strain behaviors caused by rebar corrosion. Seven RC specimens were created with variable compressive strengths, rebar diameters, and concrete cover thicknesses. To mimic in-situ conditions, the accelerated corrosion tests applied a current to the longitudinal bar and transverse bar for different periods of time to create an unbalanced chloride ion distribution. These tests evaluated the amount of rebar corrosion, corrosion cracking properties, and transverse bar strain behavior. The corrosion rate of the transverse bar was faster than that of the longitudinal bar, and cracking first occurred in the concreate around the transverse bar in the specimens with low concrete compressive strength and thin concrete cover. Corrosion cracking and rebar strain were greatly affected by the behavior of the corrosion products that resulted from the pore volume and cracking properties of the cement paste.

scholarly journals Design and Fabrication of New High Entropy Alloys for Evaluating Titanium Replacements in Additive Manufacturing

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3001 ◽  
Author(s):  
Prashant Sarswat ◽  
Taylor Smith ◽  
Sayan Sarkar ◽  
Arun Murali ◽  
Michael Free
Keyword(s):  
Corrosion Current ◽  
Cost Comparison ◽  
High Entropy Alloys ◽  
Accelerated Corrosion ◽  
Powder Bed ◽  
High Entropy ◽  
Accelerated Corrosion Tests ◽  
Hardness Tests ◽  
Before And After ◽  
And Performance

High entropy alloys (HEAs) were prepared using the powder bed fusion (PBF) technique. Among titanium free alloys AlCoCrFeNiMn, CoCr1.3FeMnNi0.7, AlCoCrFeNi1.3, and AlCoCr1.3FeNi1.3 have been further investigated. A cost comparison was done for these four alloys as well as the titanium-based alloys AlCoCrFeNiTi and AlCo0.8CrFeNiTi. Such a comparison was done in order to evaluate the performance of the titanium-free alloys as the estimated cost of these will be less than for Ti-based HEAs. Hence, we have chosen four titanium free alloys and two titanium-based alloys for further processing. All these alloys were fabricated and subsequently characterized for phase, purity and performance. Scanning electron microscopy-based images were captured for microstructure characterization. EIS-based tests and potentiodynamic scans were performed to evaluate corrosion current. Hardness tests were performed for mechanical properties evaluation. Additional testing using factorial design tests was performed to evaluate the effects of various parameters to create better PBF-based HEA samples. EBSD tests, accelerated corrosion tests (mass loss), chemical analysis after degradation, microstructure analysis before and after degradation, and mechanical property comparison for finalized samples and other similar tests were executed. The details about all these HEAs and subsequent laser processing as well as behavior of these HEAs have been included in this study. It has been observed that some of the selected alloys exhibit good performance compared to Ti-based alloys, especially with respect to improvements in elastic constant and hardness relative to commercially pure Ti.

scholarly journals Effects of bracket design on critical contact angle

2013 ◽  
Vol 83 (5) ◽  
pp. 877-884 ◽  
Author(s):  
Xiaomo Liu ◽  
Peng Ding ◽  
Jiuxiang Lin
Keyword(s):  
Contact Angle ◽  
Stainless Steel ◽  
Linear Regression ◽  
Resistance To Sliding ◽  
The Relationship ◽  
State Resistance ◽  
Critical Contact ◽  
Bracket Design

ABSTRACT Objective: To explore how the position of the bracket slots relative to the archwire influences the friction between them, and how bracket design affects the critical contact angle (θc). Materials and Methods: Two kinds of stainless steel archwires (0.016 and 0.019 × 0.025-inch) were tested against four kinds of brackets (Transmission Straight Archwire bracket, Domestic MBT bracket, Tip-Edge Plus bracket, and BioQuick self-ligation bracket) in the dry state. Resistance to sliding (RS) was measured as an increase in contact angle (θ). The value of θc was calculated by two linear regression lines. Results: Friction remained stable when θ < θc, then increased linearly when θ > θc. The θc values of the Tip-Edge Plus bracket and Transmission Straight Archwire bracket were significantly larger than those for the Domestic MBT bracket and BioQuick self-ligation bracket. Conclusions: The relationship between the archwire and bracket slot significantly affects the resistance to sliding. The “edge-off” structure of the Tip-Edge Plus bracket and Transmission Straight Archwire bracket could help to increase the θc value, and to expand the passive configuration range.

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