Bond degradation of non-uniformly corroded steel rebars in concrete

2021 ◽  
Vol 226 ◽  
pp. 111392
Author(s):  
Chuanqing Fu ◽  
Deming Fang ◽  
Hailong Ye ◽  
Le Huang ◽  
Jiandong Wang
Keyword(s):  
Bond Degradation ◽  
Steel Rebars

Pull-out and bond degradation of steel rebars in ECE concrete

1996 ◽  
Vol 26 (2) ◽  
pp. 267-282 ◽  
Author(s):  
N.M. Ihekwaba ◽  
B.B. Hope ◽  
C.M. Hansson
Keyword(s):  
Pull Out ◽  
Bond Degradation ◽  
Steel Rebars

scholarly journals Corrosion of Steel Rebars in Anoxic Environments. Part I: Electrochemical Measurements

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2491
Author(s):  
Elena Garcia ◽  
Julio Torres ◽  
Nuria Rebolledo ◽  
Raul Arrabal ◽  
Javier Sanchez
Keyword(s):  
Corrosion Rate ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Chloride Content ◽  
Offshore Platforms ◽  
Anoxic Conditions ◽  
Current Limit ◽  
Anoxic Environments ◽  
Corrosion Of Steel ◽  
Steel Rebars

The number of reinforced concrete structures subject to anoxic conditions such as offshore platforms and geological storage facilities is growing steadily. This study explored the behaviour of embedded steel reinforcement corrosion under anoxic conditions in the presence of different chloride concentrations. Corrosion rate values were obtained by three electrochemical techniques: Linear polarization resistance, electrochemical impedance spectroscopy, and chronopotenciometry. The corrosion rate ceiling observed was 0.98 µA/cm2, irrespective of the chloride content in the concrete. By means of an Evans diagram, it was possible to estimate the value of the cathodic Tafel constant (bc) to be 180 mV dec−1, and the current limit yielded an ilim value of 0.98 µA/cm2. On the other hand, the corrosion potential would lie most likely in the −900 mVAg/AgCl to −1000 mVAg/AgCl range, whilst the bounds for the most probable corrosion rate were 0.61 µA/cm2 to 0.22 µA/cm2. The experiments conducted revealed clear evidence of corrosion-induced pitting that will be assessed in subsequent research.

Suggested Empirical Models for Corrosion-Induced Bond Degradation in Reinforced Concrete

2008 ◽  
Vol 134 (2) ◽  
pp. 221-230 ◽  
Author(s):  
Kapilesh Bhargava ◽  
A. K. Ghosh ◽  
Yasuhiro Mori ◽  
S. Ramanujam
Keyword(s):  
Reinforced Concrete ◽  
Empirical Models ◽  
Bond Degradation

scholarly journals An 18-Month Analysis of Bond Strength of Hot-Dip Galvanized Reinforcing Steel B500SP and S235JR+AR to Chloride Contaminated Concrete

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 747
Author(s):  
Mariusz Jaśniok ◽  
Jacek Kołodziej ◽  
Krzysztof Gromysz
Keyword(s):  
Comparative Analysis ◽  
Bond Strength ◽  
Complex Geometry ◽  
Zinc Coating ◽  
3D Scanning ◽  
Steel Grade ◽  
Electrochemical Tests ◽  
Test Elements ◽  
Steel Rebars ◽  
Chloride Contaminated

This article describes the comparative analysis of tests on bond strength of hot-dip galvanized and black steel to concrete with and without chlorides. The bond effect was evaluated with six research methods: strength, electrochemical (measurements of potential, EIS and LPR), optical, and 3D scanning. The tests were conducted within a long period of 18 months on 48 test elements reinforced with smooth rebars ϕ8 mm from steel grade S235JR+AR and ribbed rebars ϕ8 mm and ϕ16 mm from steel grade B500SP. The main strength tests on the reinforcement bond to concrete were used to compare forces pulling out galvanized and black steel rebars from concrete. This comparative analysis was performed after 28, 180, and 540 days from the preparation of the elements. The electrochemical tests were performed to evaluate corrosion of steel rebars in concrete, particularly in chloride contaminated concrete. The behaviour of concrete elements while pulling out the rebar was observed using the system of digital cameras during the optical tests. As regards 3D scanning of ribbed rebars ϕ8 mm and ϕ16 mm, this method allowed the detailed identification of their complex geometry in terms of determining the polarization area to evaluate the corrosion rate of reinforcement in concrete. The test results indicated that the presence of zinc coating on rebars had an impact on the parameters of anchorage. In the case of ribbed rebars of 16 mm in diameter, the maximum values of adhesive stress and bond stiffness were reduced over time when compared to black steel rebars. Moreover, it was noticed that the stiffness of rebar anchorage in chloride contaminated concrete was considerably higher than in concrete without chlorides.

Inspection of Concrete-Metal Rod Interface Using Guided Waves

2000 ◽  
Author(s):  
Won-Bae Na ◽  
Tribikram Kundu ◽  
Mohammad R. Ehsani
Keyword(s):  
Lamb Wave ◽  
Guided Waves ◽  
Lamb Waves ◽  
Guided Wave ◽  
Ultrasonic Transducers ◽  
Interface Debonding ◽  
Long Distance ◽  
Steel Rebar ◽  
Steel Bars ◽  
Steel Rebars

Abstract The feasibility of detecting interface degradation and separation of steel rebars in concrete beams using Lamb waves is investigated in this paper. It is shown that Lamb waves can easily detect these defects. A special coupler between the steel rebar and ultrasonic transducers has been used to launch non-axisymmetric guided waves in the steel rebar. This investigation shows that the Lamb wave inspection technique is an efficient and effective tool for health monitoring of reinforced concrete structures because the Lamb wave can propagate a long distance along the reinforcing steel bars embedded in concrete as the guided wave and is sensitive to the interface debonding between the steel rebar and concrete.

Stainless Steel Coatings for Corrosion Protection of Steel Rebars

1996 ◽  
Author(s):  
B. Arsenault ◽  
P. Gu ◽  
J.G. Legoux ◽  
B. Harvey ◽  
J. Fournier
Keyword(s):  
Stainless Steel ◽  
Carbon Steel ◽  
Salt Spray ◽  
Chloride Ions ◽  
Metallographic Examination ◽  
316 L Stainless Steel ◽  
Parking Garages ◽  
Coating Microstructure ◽  
Stainless Steel Coatings ◽  
Steel Rebars

Abstract Steel reinforcement corrosion is one of the most serious causes of the premature deterioration of North American bridges and parking garages. Carbon steel rebars are very vulnerable to corrosion in salt contaminated concrete from deicing or coastal environment since the chloride ions induce severe corrosion as they reach the reinforcing steel rebars and depassivate the carbon steel. This paper evaluates the potential of using stainless steel coatings as a means to protect steel rebars from corrosion, especially in a salt contaminated concrete environment. The 316 L stainless steel coated coupons and rebars were prepared using Arc-sprayed and HP/HVOF processes. The corrosion performance of coatings were evaluated using linear polarization, a.c. impedance and salt spray techniques. Metallographic examination was also performed to characterize the coating microstructure.

scholarly journals Effect of the degree of corrosion on bond performance of Cement Polymer Composite (CPC) Coated steel rebars

2018 ◽  
Vol 199 ◽  
pp. 04010
Author(s):  
Deepak K. Kamde ◽  
Radhakrishna G. Pillai
Keyword(s):  
Bond Strength ◽  
Polymer Composite ◽  
Continuous Monitoring ◽  
Coated Steel ◽  
Bond Performance ◽  
Pull Out ◽  
Curing Period ◽  
Uncoated Steel ◽  
Concrete Coating ◽  
Steel Rebars

Currently, large infrastructures (bridges, highways, etc.) are designed for more than 100 years. To achieve long service life, coated rebars (mostly, cement polymer composite (CPC) coated rebars) are being used to enhance the corrosion resistance. However, inadequately coated rebars can lead to premature corrosion. This can also affect the bond between the rebar and the concrete. To assess the effect of CPC coating on bond strength, pull-out specimens of (150×150×100) mm with 12 mm diameter rebar with 100 mm embedded length were cast and tested. For this, three replica specimens with two types of reinforcement namely, i) Uncoated steel ii) CPC coated steel were cast. To induce corrosion, additional five specimens with CPC coated steel rebars were cast with premixed chloride and cured for 28 days. During the curing period, continuous monitoring of corrosion potential and rate was done and degree of corrosion was assessed. The effect of degree of corrosion on bond of steel-concrete-coating interface was quantified. The CPC coated rebars without corrosion exhibited 10% bond reduction. CPC coated rebars with corrosion exhibited 30-70% reduction in bond strength. Also, the corrosion is found to adversely influence the stiffness of the bond.

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