scholarly journals Study on the effects of green-based plant extracts and water-proofers as anti-corrosion agents for steel-reinforced concrete slabs

2021 ◽  
Vol 302 ◽  
pp. 02018
Author(s):  
Jagadeesh Bhattarai ◽  
Madan Somai ◽  
Nirmal Acharya ◽  
Ajaya Giri ◽  
Akash Roka ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Plant Extracts ◽  
Research Work ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Corrosion Properties ◽  
Cell Potential ◽  
Positive Direction ◽  
Reinforced Concrete Slabs ◽  
Corrosion Susceptibility

Widespread applications of reinforced concrete structures have been practiced since the 20th century because of their excellent properties despite their early corrosion degradation. For the control of such a problem, a design strategy of corrosion-resistant environments of the reinforced concrete structures is highly desirable for extending of a lifetime. The present research work was focused to investigate the effects of the green plant extract-based inhibitors from Vitex negundo and Catharanthus roseus leaves, and one waterproofing chemical (PtS) for controlling the corrosion susceptibility of concrete rebar using a half-cell potential method following the ASTM C876-91 standard. Both plant extracts have good anti-corrosion properties, and hence could be applied as green concrete additives to increase the corrosion resistance of the steel reinforcing bars. The anti-corrosion performance of the steel rebars in concrete is remarkably higher with the additions of 1000 and 2000 ppm plant extracts than the additions of waterproofing chemicals used, based on the shifting of corrosion potential (ϕcorr.) values to a more positive direction than −126 mV (SCE). The results agreed that both the plant extracts could be promising for the formulation of effective, ecofriendly anti-corrosion additives to delay the corrosion susceptibility of the concrete infrastructures.

Passive corrosion control and active corrosion prevention of the reinforced concrete structures by electrochemical chloride removal and inhibitors

2013 ◽  
Vol 61 (1) ◽  
pp. 32-37 ◽  
Author(s):  
Guofu Qiao ◽  
Yi Hong ◽  
Tiejun Liu ◽  
Jinping Ou
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structures ◽  
Concrete Cover ◽  
Reinforced Concrete Structures ◽  
Reinforcing Steel ◽  
Corrosion Control ◽  
Cell Potential ◽  
Content Type ◽  
Chloride Removal ◽  
Active Corrosion

Purpose – The aim of this paper was to investigate the passive corrosion control and active corrosion protective effect of the reinforced concrete structures by electrochemical chloride removal (ECR) method and inhibitors approach, respectively. Design/methodology/approach – The concentration of aggressive chloride ion distributed from the reinforcing steel to the surface of the concrete cover was analyzed during the ECR processes. Besides, the half-cell potential, the concrete resistance R c , the polarization resistance R p and the capacitance of double layer C dl of the steel/concrete system were used to characterize the electrochemical performance of the concrete prisms. Findings – The effectiveness of ECR could be enhanced by increasing the amplitude of potential or prolonging the time. Inhibitor SBT-ZX(I) could successfully prevent the corrosion development of the reinforcing steel in concrete. Originality/value – The research provides the scientific basis for the practical application of ECR and inhibitors in the field.

scholarly journals Experimental and Empirical Time to Corrosion of Reinforced Concrete Structures under Different Curing Conditions

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Ahmed A. Abouhussien ◽  
Assem A. A. Hassan
Keyword(s):  
Reinforced Concrete ◽  
Corrosion Test ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Cell Potential ◽  
Accelerated Corrosion ◽  
Curing Conditions ◽  
Expected Time ◽  
Corrosion Initiation ◽  
Accelerated Corrosion Test

Reinforced concrete structures, especially those in marine environments, are commonly subjected to high concentrations of chlorides, which eventually leads to corrosion of the embedded reinforcing steel. The total time to corrosion of such structures may be divided into three stages: corrosion initiation, cracking, and damage periods. This paper evaluates, both empirically and experimentally, the expected time to corrosion of reinforced concrete structures. The tested reinforced concrete samples were subjected to ten alternative curing techniques, including hot, cold, and normal temperatures, prior to testing. The corrosion initiation, cracking, and damage periods in this investigation were experimentally monitored by an accelerated corrosion test performed on reinforced concrete samples. Alternatively, the corrosion initiation time for counterpart samples was empirically predicted using Fick’s second law of diffusion for comparison. The results showed that the corrosion initiation periods obtained experimentally were comparable to those obtained empirically. The corrosion initiation was found to occur at the first jump of the current measurement in the accelerated corrosion test which matched the half-cell potential reading of around −350 mV.

Ultrasonic C-Scan Imaging: Preliminary Evaluation for Corrosion and Void Detection in Posttensioned Tendons

2003 ◽  
Vol 1827 (1) ◽  
pp. 44-52 ◽  
Author(s):  
Shivprakash Iyer ◽  
Andrea J. Schokker ◽  
Sunil K. Sinha
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structures ◽  
Corrosion Monitoring ◽  
Reinforced Concrete Structures ◽  
Preliminary Evaluation ◽  
Cell Potential ◽  
Impact Echo ◽  
Bridge Structures ◽  
Processing Techniques ◽  
User Friendly

Corrosion of the nation’s transportation infrastructure is a widespread and costly problem. The most prevalent durability issue in reinforced concrete structures is chloride-induced corrosion of the reinforcing steel. A reliable method of determining grout voids and corrosion levels in posttensioned bridge structures is needed. Traditional techniques of corrosion monitoring (e.g., half-cell potential and corrosion rate measurement) are problematic when used in this type of structure, as are standard nondestructive evaluation (NDE) methods, such as impact echo. C-scan imaging, an ultrasonic technique used primarily in the composites industry for detecting delamination, is examined as a method of evaluating grouted posttensioned tendons. This method exhibits many promising qualities: it can be used for internal or external tendons and on metal or plastic ducts; access to only one side of a specimen is required; strong imaging allows easy interpretation of results; the technique poses no risk to users or the environment; and the method has strong potential for development as a handheld field tool. The C-scan technique may be valuable for the investigation of not only posttensioning applications but other types of reinforced concrete structures as well. Results of preliminary investigations on lab specimens indicate that the C-scan technique holds promise. The ultimate goal of the research is to provide a user-friendly, robust system for the NDE of posttensioned tendons for voids, corrosion, and wire breaks. Recommendations for optimal acquisition and processing techniques as well as for the future development of the equipment as a field tool are proposed.

Application of Repair and Anti-Corrosion Technology on Reinforced Concrete Structures of a Domestic Wharf

2011 ◽  
Vol 189-193 ◽  
pp. 165-168
Author(s):  
Xiao Dong Zhao ◽  
Xi Qiu Fan ◽  
Mei Ling Tian
Keyword(s):  
Reinforced Concrete ◽  
Research Work ◽  
Concrete Structures ◽  
Detection Methods ◽  
Reinforced Concrete Structures ◽  
Reinforced Concrete Structure ◽  
The Status ◽  
Multiple Detection ◽  
Technical Discussion ◽  
Technical Basis

According to the status and service environment of a domestic wharf, the corrosion of reinforced concrete structure was evaluated by multiple detection methods, on the base of which the corresponding repair and anti-corrosion program were adopted, thus good preservative effect was achieved. The research work and demonstration project are expected to provide technical discussion and reference for peer experts, as well as technical basis for the corrosion protection of reinforced concrete structures in similar marine environment.

Half-cell potential measurements—Potential mapping on reinforced concrete structures

2003 ◽  
Vol 36 (7) ◽  
pp. 461-471 ◽  
Author(s):  
B. Elsener ◽  
C. Andrade ◽  
J. Gulikers ◽  
R. Polder ◽  
M. Raupach
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Half Cell ◽  
Cell Potential ◽  
Potential Mapping

scholarly journals Azadirachta indica Leaf Extract as Green Corrosion Inhibitor for Reinforced Concrete Structures: Corrosion Effectiveness against Commercial Corrosion Inhibitors and Concrete Integrity

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3326
Author(s):  
Benjamin Valdez-Salas ◽  
Ramiro Vazquez-Delgado ◽  
Jorge Salvador-Carlos ◽  
Ernesto Beltran-Partida ◽  
Ricardo Salinas-Martinez ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Carbon Steel ◽  
Corrosion Inhibitor ◽  
Construction Industry ◽  
Azadirachta Indica ◽  
Leaf Extract ◽  
Concrete Structures ◽  
Chloride Ions ◽  
Reinforced Concrete Structures ◽  
Cell Potential

The construction industry has extensively demanded novel green inhibition strategies for the conservation and protection of carbon steel-reinforced concrete structures. For the first time, the effect of Azadirachta indica leaf extract (Neem) as a potential corrosion inhibitor of carbon steel in reinforced concrete under corrosion in saline simulated media was evaluated. To assess the corrosion inhibition behavior of the Neem natural organic extract, three inorganic commercial inhibitors were tested to compare following the criteria established by Stratful for half-cell potential under a simulated chloride environment. Moreover, the effect of concrete integrity by the Neem treatment was recorded after different temperature conditions, slump, weight alteration, air content, compressive strength, and chloride-ions penetration. The results suggested that the Neem treatments did not alter the concrete integrity and the physicochemical parameters. We reached a promoted long-term corrosion protection of 95% after 182 days of evaluation. Thus far, our current results open up a new promising “green” road to the conservation of carbon steel in reinforced concrete for the construction industry.

Galvanic Anodes for Reinforced Concrete Structures: A Review

CORROSION ◽  
10.5006/2613 ◽  
2018 ◽  
Vol 74 (6) ◽  
pp. 715-723 ◽  
Author(s):  
Oladis Troconis de Rincón ◽  
Andrés Torres-Acosta ◽  
Alberto Sagüés ◽  
Miguel Martinez-Madrid
Keyword(s):  
Reinforced Concrete ◽  
Research Work ◽  
Concrete Structures ◽  
The United States ◽  
Field Application ◽  
Reinforced Concrete Structures ◽  
Atmospheric Conditions ◽  
Metal Mesh ◽  
Zinc Alloys ◽  
Sacrificial Anodes

In recent years, the use of sacrificial anodes for cathodic protection in reinforced concrete structures has increased, reflecting ease of installation, low-maintenance requirements, as well as desirability in prestressed concrete structures where the naturally controlled protection potential decreases the risk of hydrogen embrittlement. Zinc-based alloys have been among the most evaluated galvanic materials for concrete structures, especially in the United States, in many applications: thermal spray, superficial metal/mesh with and without hydrogel adhesive, embedded in concrete (point anodes) with or without salt activator, etc. However, the protection capacity lifetime of zinc alloys as used has been questioned based both on laboratory and on field application studies. Aluminum alloys have also been evaluated, sometimes showing better results as anode materials than zinc alloys. However, both zinc and aluminum alloy anodes may experience limited applicability in concrete structures exposed only to atmospheric conditions, as opposed to those in immersed, tidal, and splash zone service. This paper presents a review of the research work in the literature to date for both laboratory and field evaluations, toward identifying technically relevant situations where the use of sacrificial anodes may or may not be a practical option for reinforcement protection in concrete structures.

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