Electro-Migration Corrosion Inhibitors for Chlorides Induced Corrosion in Reinforced Concrete

In connection with the reinforced concrete deterioration by chlorides, a new electro-migration corrosion inhibitors which can move to the surface of rebar covered by 100mm protective layer, was used. And through the test of macro galvanic current, weight lost and corrosion potential, the effect of corrosion inhibitors was studied. The result showed that, with the reasonable treatment, a stable, long-term effectiveness of corrosion inhibition could be obtained.

Download Full-text

The Reinforced Concrete Durability and Rebar Erosion Monitoring

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.446-449.3252 ◽

2012 ◽

Vol 446-449 ◽

pp. 3252-3258

Author(s):

Jin Yang Zhang ◽

De Mi Cui ◽

Lie Min Lv ◽

Zhi Yang

Keyword(s):

Reinforced Concrete ◽

Service Life ◽

Protective Layer ◽

Concrete Surface ◽

Monitor System ◽

Concrete Durability ◽

Information Feedback ◽

Starting Time ◽

Cast Concrete

On the basis of the advantages of low construction cost, remarkable dynamics property, easy cast moulding and more controllable construction, the reinforced concrete construct are widely applied in buildings and main structures of constructions in China. However, the reinforced concrete is found more or less aging after many years’ utilization and erosion from the environment, which will lead to a hidden risk to affect its functions. After technical development for decades, the concrete can assure its durability under normal situation, yet the function would be deteriorated due to the erosion from the complex and harsh environment to make it hardly reach its designed service life. With the assist of CorroWatch erosion monitor system, the concrete structures’ erosion can kept watched on to obtain the depassivation development and information feedback of some key data dynamically and in long term so as to foresee precisely the erosion starting time. The newly cast concrete depassivation frontline is located on concrete surface and will tend to go through the protective layer and penetrate towards rebar as time goes on. Its structure service life can be enhanced with the re-designed durability in terms of the mentioned characters and do well the erosion proof measures.

Download Full-text

Long-Term Efficiency of Two Organic Corrosion Inhibitors for Reinforced Concrete

Materials Science Forum ◽

10.4028/www.scientific.net/msf.636-637.1059 ◽

2010 ◽

Vol 636-637 ◽

pp. 1059-1064 ◽

Cited By ~ 7

Author(s):

E.V. Pereira ◽

R.B. Figueira ◽

Manuela M. Salta ◽

I.T.E. Fonseca

Keyword(s):

Reinforced Concrete ◽

Environmental Conditions ◽

Corrosion Inhibitors ◽

Electrochemical Techniques ◽

Concrete Structures ◽

Concrete Slabs ◽

Reinforced Concrete Structures ◽

Reinforcement Corrosion ◽

Organic Corrosion Inhibitors

In this paper the efficiency of two organic corrosion inhibitors, a migratory and an admixture inhibitor, was evaluated by electrochemical techniques in solutions simulating the interstitial electrolyte of concrete and on concrete slabs exposed to natural environmental conditions over a five-year period. From obtained results, the usefulness of the two products is discussed aiming its application in new structures to prevent chlorides induced corrosion and as a curative method for repairing reinforced concrete structures contaminated with chlorides and affected by reinforcement corrosion.

Download Full-text

Effect of Surface Applied Organic and Inorganic Corrosion Inhibitors on Reinforced Steel in Concrete

International Journal of Engineering and Advanced Technology - Regular Issue ◽

10.35940/ijeat.b4092.129219 ◽

2019 ◽

Vol 9 (2) ◽

pp. 3023-3031

Keyword(s):

Weight Loss ◽

Corrosion Inhibition ◽

Corrosion Inhibitors ◽

Inhibition Efficiency ◽

Protective Layer ◽

Concrete Surface ◽

Cell Potential ◽

Reinforced Steel ◽

Corrosion Inhibition Efficiency ◽

Effect Of Surface

This paper presents the results of an experimental investigation carried out to study the effect of surface applied organic and inorganic corrosion inhibitors on reinforced steel in concrete. The reinforcement bars were coated with Neem powder (organic inhibitor) and Zinc powder (inorganic inhibitor) as corrosion inhibitors. The samples of beams of size 100X100X640mm having 4 steel bars as reinforcement were prepared and cured in normal water for 15 days and in saline environment for 42 days. The inhibitors were applied in the form of 2 coats, 4 coats and blend of both. The grade of concrete used was M30. Half-cell Potential and Weight loss measurements were carried out to determine the efficiency of corrosion inhibitors [11]. The corrosion inhibition efficiency of controlled specimen and coated specimens were compared. From the results it was seen that samples with 4 coats of Neem showed 44% inhibition efficiency as compared to control specimens. Similarly specimens with two coats of Neem, four coats of Neem and Zinc also showed better corrosion inhibition efficiency. Highest weight loss was observed in case of control specimen. The study concludes that use of surface applied corrosion inhibitors prove efficient in enhancing the corrosion inhibition efficiency of concrete. Surface applied corrosion inhibitors provide protective layer to the reinforcement thereby protecting it from corrosion and increasing the durability of the structure. This type of technique of using corrosion inhibitors in concrete can be used in various structures such as buildings, bridges, sewage pipes, marine structures, abutments & piers, RCC roads which are subjected to harsh environmental conditions.

Download Full-text

Study of Garlic Extract as a Green Corrosion Inhibitor for Mild Steel in Acidic Media

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.960-961.118 ◽

2014 ◽

Vol 960-961 ◽

pp. 118-125 ◽

Cited By ~ 1

Author(s):

Bo Yang ◽

Wu Chen ◽

Dan Hua Mu

Keyword(s):

Amino Acids ◽

Hydrochloric Acid ◽

Corrosion Inhibition ◽

Corrosion Inhibitors ◽

Corrosion Potential ◽

Garlic Extract ◽

Main Ingredient ◽

Acidic Media ◽

Green Corrosion Inhibitor ◽

Inhibition Performance

This paper studies extract as corrosion inhibitors extracted from garlic. The IR spectrum analysis of the extract shows that the main ingredient of extract is amino acids, and the better extracting condition is that 30°C50mL 10%H2SO4and 20g peeled garlic react for 120.0h, and composite amino acids content in the extract is 19.0mg/L. The result of corrosion inhibition performance using static weight loss shows that the dosage of the extract, temperature and concentration of acidic mediums have effect on corrosion inhibition remarkably. The corrosion inhibitive efficiency for A3 steel is 93.26% in 5% Hydrochloric acid and 79.2% in5% mud acid when the dosage of the garlic extract is 4.0%(V/V) and 6.0%(V/V),respectively. The investigated results of electrochemistry performance of the extract indicates that corrosion potential of A3 steel shift in negative direction both in Hydrochloric acid and in mud acid, which indicates that the extract are inhibitors of inhibiting cathodic corrosion, and circular-arc radius of alternating-current impedance spectroscopy increase notably in acidic medium, and corrosion inhibition effect is remarkable. Therefore, it is feasible to extract inhibitors from garlic.

Download Full-text

Self-healing performance of smart coatings modified with different corrosion inhibitors

University of the Future: Re-Imagining Research and Higher Education ◽

10.29117/quarfe.2020.0002 ◽

2020 ◽

Author(s):

Sehrish Habib ◽

Eman Fayyed ◽

Muddasir Nawaz ◽

Adnan Khan ◽

Abdul Shakoor ◽

...

Keyword(s):

Corrosion Inhibition ◽

Corrosion Inhibitors ◽

Inhibition Efficiency ◽

Electrochemical Impedance ◽

Protective Layer ◽

Sem Analysis ◽

Self Healing ◽

Defect Site ◽

Corrosion Inhibition Efficiency ◽

Eis Measurements

Corrosion results in considerable materials and equipment failure. According to one survey, about 1/4 to 1/3 of the total interruption in industries is due to detrimental effects of corrosion. It is, therefore, important to prevent corrosion to guarantee the reliability of the assets. The present work is aimed to explore the purpose of CeO2 as a carrier for corrosion inhibitors and its capability to release inhibitors, to achieve decent corrosion protection efficiency in epoxy-based polymeric nanocomposite coatings. Amine-based corrosion inhibitors (N-methylthiourea NMTU and Dodecylamine DDA) were used for CeO2 nano container modification, and corrosion inhibition efficiency has been explored utilizing electrochemical impedance spectroscopy (EIS) in 3.5 wt% NaCl solution. Loading of inhibitor into nanocontainer has been confirmed through Fouriertransform infrared spectroscopy (FTIR) and Brunauer-Emmett-Teller (BET). It was observed that 25% and 29.75% w/w of NMTU and DDA were loaded into nanocontainers, confirmed through Thermogravimetric analysis (TGA). Scanning electron microscopy (SEM) analysis endorsed the formation of a protective layer on a scratch area to protect steel from the external environment. This protective layer played a very important role in protecting steel from progressing corrosion on the defect site from the aggressiveness of the solution. EIS measurements revealed the decent corrosion inhibition efficiency of these inhibitors in order of DDA>NMTU. As a result, they are a favorable solution for longer endurance of coated piping steel and decreased operation expense contributing to economic savings, materials reliability and safety.

Download Full-text

The influence of the mineral additives on the carbonation of cement composites

MATEC Web of Conferences ◽

10.1051/matecconf/201819604062 ◽

2018 ◽

Vol 196 ◽

pp. 04062 ◽

Cited By ~ 1

Author(s):

Paweł Woliński ◽

Piotr Woyciechowski ◽

Beata Jaworska ◽

Grzegorz Adamczewski ◽

Daniel Tokarski ◽

...

Keyword(s):

Reinforced Concrete ◽

Protective Layer ◽

Concrete Cover ◽

Free Calcium ◽

Cement Composites ◽

Reinforced Concrete Structure ◽

Common Causes ◽

The Moment ◽

Mineral Additives

In practice, it is usually assumed that the durability of basic structural elements should not be less than the expected durability of the building. Reinforced concrete constructions, designed and made with quality requirements, are durable. However, each reinforced concrete structure, from the moment it is made, is gradually degraded, and one of the reasons for its destruction is often the corrosion of the concrete and hence the reinforcement. For the long-term use of reinforced concrete constructions, the most important thing is that a thin protective layer on the steel surface protects the reinforcing steel from rusting. One of the most common causes of corrosion in the reinforcement is the damage of this layer as a result of the carbonation of the concrete cover. The rate of carbonation depends on many factors, such as concrete compactness, concentration of CO2, concrete moisture, content of free calcium dioxide, content of mineral additives, etc. When the carbonated layer reaches the steel reinforcement layer, protection of steel from corrosion ceases to exist. The aim of the presented research was to determine the influence of mineral additives used as a compound of concrete on the carbonation of concrete and polymer-cement composites.

Download Full-text

Improvement Of Curvilinear Diagrams Of Concrete Deformation

Promyshlennoe i Grazhdanskoe Stroitel stvo ◽

10.33622/0869-7019.2019.08.99-104 ◽

2019 ◽

pp. 99-104

Keyword(s):

Reinforced Concrete ◽

Peak Load ◽

Experimental Studies ◽

Concrete Structures ◽

Deformation Model ◽

Reinforced Concrete Structures ◽

Significant Difference ◽

Deformation Diagrams

Problems when calculating reinforced concrete structures based on the concrete deformation under compression diagram, which is presented both in Russian and foreign regulatory documents on the design of concrete and reinforced concrete structures are considered. The correctness of their compliance for all classes of concrete remains very approximate, especially a significant difference occurs when using Euronorm due to the different shape and sizes of the samples. At present, there are no methodical recommendations for determining the ultimate relative deformations of concrete under axial compression and the construction of curvilinear deformation diagrams, which leads to limited experimental data and, as a result, does not make it possible to enter more detailed ultimate strain values into domestic standards. The results of experimental studies to determine the ultimate relative deformations of concrete under compression for different classes of concrete, which allowed to make analytical dependences for the evaluation of the ultimate relative deformations and description of curvilinear deformation diagrams, are presented. The article discusses various options for using the deformation model to assess the stress-strain state of the structure, it is concluded that it is necessary to use not only the finite values of the ultimate deformations, but also their intermediate values. This requires reliable diagrams "s–e” for all classes of concrete. The difficulties of measuring deformations in concrete subjected to peak load, corresponding to the prismatic strength, as well as main cracks that appeared under conditions of long-term step loading are highlighted. Variants of more accurate measurements are proposed. Development and implementation of the new standard GOST "Concretes. Methods for determination of complete diagrams" on the basis of the developed method for obtaining complete diagrams of concrete deformation under compression for the evaluation of ultimate deformability of concrete under compression are necessary.

Download Full-text