scholarly journals Effect of Imidazoline Inhibitor on the Rehabilitation of Reinforced Concrete with Electromigration Method

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 398 ◽  
Author(s):  
Chonggen Pan ◽  
Jianghong Mao ◽  
Weiliang Jin
Keyword(s):  
Reinforced Concrete ◽  
Extraction Efficiency ◽  
Corrosion Potential ◽  
Steel Bar ◽  
Chloride Migration ◽  
Significant Difference ◽  
Steel Bars ◽  
Novel Method ◽  
Electrochemical Chloride Extraction ◽  
High Chloride

Steel bars embedded in reinforced concrete are vulnerable to corrosion in high chloride environments. Bidirectional electromigration rehabilitation (BIEM) is a novel method to enhance the durability of reinforced concrete by extracting chloride out of concrete and introducing an inhibitor to the surface of the steel bar under the action of an electric field. During the migration process, a higher ionization capacity of the inhibitor with a symmetrical molecular structure was introduced. A new imidazoline inhibitor was, therefore, employed in this study due to its great ionization capacity. The effect of imidazoline and triethylenetetramine inhibitor on chloride migration, corrosion potential, and strength of concrete were explored. The research results showed that the effect of chloride extraction and electrochemical chloride extraction made no significant difference on the surface of the concrete, where chloride extraction efficiency was more than 70%, and the chloride extraction efficiency was more than 90% around the location of the steel. while a dry-wet cycle test, the potential of concrete increased by about 200 mV by mixing imidazoline inhibitor. The imidazoline inhibitor was found to be effective at facilitating chloride migration and ameliorating corrosion, meanwhile, it had a negligible impact on the concrete’s strength.

scholarly journals Study on the potential change of corroded reinforced concrete in ECE with MPC-CFRP as anode

2020 ◽  
Vol 319 ◽  
pp. 06005
Author(s):  
Yue Li ◽  
Xiuhu Zhang ◽  
S.M.Ali S. Hejazi
Keyword(s):  
Composite Material ◽  
Reinforced Concrete ◽  
Current Density ◽  
Good Effect ◽  
Steel Bar ◽  
Steel Bars ◽  
Cfrp Composite ◽  
Current Densities ◽  
Electrochemical Chloride Extraction ◽  
Corrosion Of Steel

Aiming at the rust removal requirements of reinforced concrete, the MPC-CFRP composite material was used as the external anode, and the Electrochemical chloride extraction (ECE) method was used to test the polarization curve of the steel bar under different ECE current densities, and the potential changes of the steel bar at different times were analyzed. The results show that the ECE system with MPC-CFRP as the external anode has a good effect of reducing the corrosion rate and the risk of corrosion of steel bars. The current density of 3A/m2is higher than that of 1A/m2in dechlorination efficiency. After 28 days of ECE, the current density of 1A/m2and 3A/m2can re passivate the reinforcement.

Magnetoelastic Measurements of Steel Stress under Uniaxial Loading

2006 ◽  
Vol 321-323 ◽  
pp. 377-380 ◽  
Author(s):  
Hong C. Rhim ◽  
Bo Hwan Oh ◽  
Hyo Seon Park
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structures ◽  
Uniaxial Loading ◽  
Magnetic Response ◽  
Reinforced Concrete Structures ◽  
Test Results ◽  
Traditional Technique ◽  
Steel Bar ◽  
Steel Bars ◽  
Different Diameters

An attempt has been made to measure existing steel stress using magnetoelasticity. A device has been developed and used for the measurement of magnetism in response to the deformation of a steel bar. The proposed technique can be used for the assessment of existing reinforced concrete structures by the measurements of steel stress embedded inside concrete. A traditional technique requires to break the existing steel bar to measure existing strain. However, the proposed technique is developed to measure the stress without damaging the steel bar. A successful application of magnetoelasticity depends on the establishment of relationship between elastic and magnetic response due to loading. To investigate the correlation between the two, steel bars are loaded in tension under uniaxial loading while the magnetic reading is recorded. Based on the test results, equations are suggested to predict stress for steel bars with different diameters.

scholarly journals Experimental Study of Replacement the Tension Reinforcing Bars in Concrete Beams by Steel Pipes

2018 ◽  
Vol 7 (4.20) ◽  
pp. 229
Author(s):  
Labeeb Saadoon Al-Yassri ◽  
Alaa Mahdi Al-Khekany ◽  
Hajer Satea Abbas
Keyword(s):  
Reinforced Concrete ◽  
Construction Projects ◽  
Concrete Beams ◽  
Small Diameter ◽  
Reinforced Concrete Beams ◽  
Steel Pipe ◽  
Steel Pipes ◽  
Steel Bar ◽  
Steel Bars ◽  
The Difference

Structures designed with reinforced concrete beams are used extensively in construction projects because of their functional and economic features. In this research, tested concrete beams were cast and reinforced with small diameter steel pipes and /or steel bars as flexural reinforcement to study the effect of this configuration of reinforcement on the structural behavior of reinforced concrete beams. The idea of this research involves performing and testing of four reinforced concrete beams reinforced by small diameter steel pipes with different percentages of replacement with traditional steel bars (0%, 33%, 66% and 100%). The experimental results showed that using of steel pipes reduces the flexural capacity by (2.7, 18.3, 37.5%) if compared with traditional steel bar according to the replacement percentages of (33%, 66%, and 100%) respectively. Moreover, the stiffness of beams reinforced with steel pipes (fully or partially) decreased as a result of the difference in the mechanical properties between steel bar and the steel pipe and also, the bond strength reduction between the smooth steel pipe and surrounded concrete.  

scholarly journals ULTRASONIC PULSE VELOCITY TEST OF REINFORCED CONCRETE WITH INDUCED CORROSION

2017 ◽  
Vol 7 (2) ◽  
pp. 9-17 ◽  
Author(s):  
Jason Maximino Co Ongpeng
Keyword(s):  
Reinforced Concrete ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Reinforcing Bars ◽  
Accelerated Corrosion ◽  
Steel Bar ◽  
Significant Damage ◽  
Steel Bars ◽  
Reinforced Steel

Non-destructive test has been applied to measure damage in structures. Common structures are assessed with the use of practical and easy application of ultrasonic pulse velocity (UPV). In this paper, the damage brought by corrosion was investigated using Proceq Punditlab having 54 kHz transducers oriented in direct transmission under the UPV. Fifty-four reinforced concrete of size 150 mm x 250 mm x 300 mm with two 10mm diameter reinforcing bars (Grade 40) and one 6mm diameter stainless steel bar (Type 304) was cast and tested. It had varying water cement ratio of 45%, 50%, and 55%with two conditions at day 0 (after curing), day 14, and day 28: non-accelerated condition under air-drying and accelerated condition using impressed current technique (ICT). The UPV test was conducted in each layer where reinforced steel bars were present and absent. It was found out that UPV test results was insignificant to all non-accelerated concrete, while it indicated significant damage for accelerated corrosion rate of more than 8 mm per year. In accelerated condition, the decrease in strength under UPV test was more than 20% for all specimens along the reinforced bars, and less than 15% for all specimens along the layer with no steel bars. This showed that the effect of corrosion greatly affects the entirety of structures near and far from the placement of reinforcing steel bars.

scholarly journals The Effect of a Corrosion Inhibitor on the Rehabilitation of Reinforced Concrete Containing Sea Sand and Seawater

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1480 ◽  
Author(s):  
Chonggen Pan ◽  
Xu Li ◽  
Jianghong Mao
Keyword(s):  
Reinforced Concrete ◽  
Corrosion Inhibitor ◽  
Control Experiment ◽  
Chloride Ion ◽  
Chloride Ions ◽  
Maximum Value ◽  
Steel Bar ◽  
Sea Sand ◽  
Chlorine Ions ◽  
Electrochemical Chloride Extraction

Concrete made with sea sand and seawater is rich in chlorine ions which are the main factors that induce corrosion of the reinforcement. In this study, an innovative method to rehabilitate reinforcement is presented; the concentrations of chloride ions and the corrosion inhibitor in concrete were measured. Electrochemical chloride extraction (ECE) was applied as a control experiment via using saturated Ca(OH)2 solution as an external electrolyte. Bidirectional electromigration (BIEM)technology combined with the corrosion inhibitor could not only remove the chloride ions but also protect the steel bar in concrete, and animidazoline inhibitor mixed in concrete is more effective than thetriethylenetetramine inhibitor due to the specific molecular structure. It was found that the optimum ratio of N/Cl reached the maximum value 3.3, when the concentration of inhibitor was 1. Meanwhile, the experimental results also revealed that the corrosion inhibitor and chloride ion concentrations reached necessary levels on the surface of the steel, and the corrosion inhibitor migrated effectively. Overall, the contents of imidazoline and triethylenetetramine inhibitor in seawater concrete are0.75% and 1%, respectively. The results demonstrate that the addition of the corrosion inhibitor and the application of bidirectional electromigration would effectively improve the durability of reinforced concrete containing sea sand and seawater.

Effects of Coating/Electroplating on Corrosion Resistance of Steel Bar in Reinforced Concrete

2012 ◽  
Vol 446-449 ◽  
pp. 3176-3179 ◽  
Author(s):  
Qun Zhou ◽  
Zhong He Shui ◽  
Yi De Xiao ◽  
Chang Sheng Xu
Keyword(s):  
Corrosion Resistance ◽  
Reinforced Concrete ◽  
Surface Treatment ◽  
Equivalent Circuit ◽  
Surface Coating ◽  
Corrosion Process ◽  
Steel Bar ◽  
Study Results ◽  
Steel Bars ◽  
Corrosion Of Steel

One of the main reasons for the damage of reinforced concrete is the expansion caused by corrosion of steel bar in concrete. In this paper, the equivalent circuit that inflects corrosion process of steel bars in reinforced concrete was analyzed, with the A.C.Impedance Spectrum method. And the effects of surface treatment of the bars on corrosion resistance of the reinforced concrete were investigated. Study results show that the surface coating (plating) on the built-in reinforcement can effectively prevent corrosion of steel bar, thereby enhancing the durability of concrete structures.

scholarly journals Evaluating the Early-Age Crack Induction in Advanced Reinforced Concrete Pavement Using Partial Surface Saw-Cuts

2021 ◽  
Vol 11 (4) ◽  
pp. 1659
Author(s):  
Muhammad Kashif ◽  
Ahsan Naseem ◽  
Nouman Iqbal ◽  
Pieter De Winne ◽  
Hans De Backer
Keyword(s):  
Reinforced Concrete ◽  
Concrete Pavement ◽  
Early Age ◽  
Fe Model ◽  
Induction Method ◽  
Rigid Pavement ◽  
Partial Length ◽  
Steel Bar ◽  
Steel Bars ◽  
Cracking Characteristics

The technological innovation of continuously reinforced concrete pavement (CRCP) that contains a significantly reduced amount of reinforcement and the same fundamental behavior as CRCP is called advanced reinforced concrete pavement (ARCP). This new concept of a rigid pavement structure is developed to eliminate unnecessary continuous longitudinal steel bars of CRCP by using partial length steel bars at predetermined crack locations. In Belgium, partial surface saw-cuts are used as the most effective crack induction method to eliminate the randomness in early-age crack patterns by inducing cracks at the predetermined locations of CRCP. The reinforcement layout of ARCP is designed based on the distribution of steel stress in continuous longitudinal steel bar in CRCP and the effectiveness of partial surface saw-cuts as a crack induction method. The 3D finite element (FE) model is developed to evaluate the behavior of ARCP with partial surface saw-cuts. The early-age crack characteristics in terms of crack initiation and crack propagation obtained from the FE simulation are validated with the field observations of cracking characteristics of the CRCP sections in Belgium. The finding indicates that there is fundamentally no difference in the steel stress distribution in the partial length steel bar of ARCP and continuous steel bar of CRCP. Moreover, ARCP exhibits the same cracking characteristics as CRCP even with a significantly reduced amount of continuous reinforcement.

scholarly journals Effects of the zinc and zinc-nickel alloys electroplating on the corrodibility of reinforced concrete rebars

2016 ◽  
Vol 9 (4) ◽  
pp. 595-605 ◽  
Author(s):  
F. A. CEDRIM ◽  
V. L. S. ALMEIDA ◽  
C. A. C. SOUZA ◽  
M. D. JESUS ◽  
D. V. RIBEIRO
Keyword(s):  
Reinforced Concrete ◽  
Nickel Alloys ◽  
Corrosion Potential ◽  
Salt Spray ◽  
Chloride Ions ◽  
Nacl Solution ◽  
Steel Bars ◽  
Quantitative Analyses ◽  
Electroplating Process ◽  
Zinc Nickel

Abstract This paper shows the analysis performed on the corrosion parameters of three groups of reinforcing steel bars, two of these coated by electroplating process with Zinc (Zn) and Zinc-Nickel (Zn-Ni), and the other without any coating. It was used reinforced concrete specimens, which ones were grouped and then subjected to two different corrosion accelerating methods: aging wetting/drying cycles and salt spray exposure. Corrosion potential was measured to qualitative monitoring of the process and, after the end of the tests, corrosion rate was estimated by measuring the mass loss, to quantitative analyses. As it was expected, coated bars presented a better performance than the average bars regarding the corrosion resistance in chloride ions containing environments. It was also observed that the drying/ NaCl solution wetting cycles seems to be more severe than salt spray fog apparatus with respect to the acceleration of corrosion process.

Bond Behaviors between Polymer Cement Coated Steel Bar Subjected to Environmental Action and Concrete

2016 ◽  
Vol 711 ◽  
pp. 1105-1110
Author(s):  
Yuan Liang Xiong ◽  
Kun Rong Wang ◽  
Zhi Yong Liu
Keyword(s):  
Reinforced Concrete ◽  
Bond Strength ◽  
Failure Modes ◽  
Environmental Action ◽  
Chloride Ingress ◽  
Coated Steel ◽  
Pull Out ◽  
Uncoated Steel ◽  
Steel Bar ◽  
Steel Bars

The bond behaviors (failure modes, bond strength, bond stress slip curves) between steel bars coated with polymer modified cement-based coating and concrete as well as effect of carbonation and chloride ingress on the bond behaviors were studied in this paper. Twenty-four concentrically reinforced concrete cubes were cast and pull-out tests under monotonic loading were carried out. The results indicated that the polymer modified cement-based coating can be well bonded with steel bar and the failure mode of all the specimens is splitting. The typical polymer cement-based coating could enhance the bond strength slightly of the uncoated steel bar with concrete in this experiments. But the bond strength were all depressed between the coated steel bars subjected to carbonation and chloride ingress and concrete.

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