Studying chloride ions and corrosion properties of reinforced concrete with a green inhibitor and plasticizers

2020 ◽  
Vol 21 (5) ◽  
pp. 1894-1904
Author(s):  
Shaymaa A. Abdulsada ◽  
Tamás I. Török
Keyword(s):  
Reinforced Concrete ◽  
Chloride Ions ◽  
Corrosion Properties ◽  
Green Inhibitor

scholarly journals Determination of the neutralization depth of concrete under the aggressive environment influence

2018 ◽  
Vol 33 ◽  
pp. 02010 ◽  
Author(s):  
Anastasia Morzhukhina ◽  
Stanislav Nikitin ◽  
Elena Akimova
Keyword(s):  
Reinforced Concrete ◽  
Chloride Ions ◽  
The Body ◽  
Chemical Plants ◽  
Reinforced Concrete Structure ◽  
Load Bearing Capacity ◽  
High Rise ◽  
Capacity Loss ◽  
Air Penetration

Aggressive environments have a significant impact on destruction of many reinforced concrete structures, such as high-rise constructions or chemical plants. For example, some high-rise constructions are equipped with a swimming pool, so they are exposed to chloride ions in the air. Penetration of aggressive chemical substances into the body of concrete contributes to acceleration of reinforced concrete structure corrosion that in turn leads to load bearing capacity loss and destruction of the building. The article considers and analyzes the main technologies for calculating penetration depth of various aggressive substances into the body of concrete. The calculation of corrosion depth was made for 50-year service life.

scholarly journals Experimental study of the influence of crack width due to corrosion behaviour using different measurement methods and different exposures

2019 ◽  
Vol 289 ◽  
pp. 08005
Author(s):  
Martin Schneider ◽  
Georg Gardener
Keyword(s):  
Reinforced Concrete ◽  
Crack Width ◽  
Corrosion Behaviour ◽  
Concrete Strength ◽  
Concrete Structures ◽  
Chloride Ions ◽  
Reinforced Concrete Structures ◽  
Reinforcing Steel ◽  
Surface Corrosion ◽  
Potential Mapping

Corrosion of reinforcing steel has a great influence in reducing the lifetime of concrete structures; Carbonation of the concrete pore solution causes surface corrosion on the steel and diffusion of chloride ions through the capillary system of the concrete cover causes pitting corrosion on the steel surface. Corrosion of metals is highly dependent on the environmental conditions. Exposure to chloride ions can be critical to the service life of reinforced concrete structures. The durability of reinforced concrete structures exposed to deicing salt or marine environments can be affected by impact of chloride ions. Detection methods for the rate of corrosion of non-destructive and destructive procedures were analysed. The potential mapping applied on the concrete surface was discussed as a standard method for corrosion detection and will be explained in detail including the application boundaries of the method. It is assumed that the corrosion behaviour of reinforcing steel depends on crack widths. To analyse that, 8 coated and 8 uncoated test samples with different concrete strength classes were used. The concrete objects were exposed to a 3% sodium chloride solution. The corrosion behaviour of reinforcing steel is analysed by using potential mapping with different reference electrodes (Ag/AgCl and Cu/CuSO4). The results show a significant correlation between crack size and protection system on the surface. The maximum crack width with a low indication of corrosion was found to be 0.1 mm.

Seismic Performance Assessment of Offshore Reinforced Concrete Bridges Using the Force Analogy Method

2016 ◽  
Vol 16 (05) ◽  
pp. 1550012 ◽  
Author(s):  
Yu Zhang ◽  
Hong-Nan Li ◽  
Gang Li
Keyword(s):  
Reinforced Concrete ◽  
Performance Assessment ◽  
Seismic Performance ◽  
High Efficiency ◽  
Pushover Analysis ◽  
Chloride Ions ◽  
Initial Stiffness ◽  
Seismic Performance Assessment ◽  
Analogy Method ◽  
Plastic Mechanism

In this paper, the seismic performance of offshore reinforced concrete (RC) bridges during their life cycle periods is assessed by the pushover analysis based on the concept of the force analogy method (FAM). The governing equations and implementation process of the proposed pushover method are first derived. The material nonlinearity is modeled by the local plastic mechanism, which is capable of simulating the monotonic strength hardening and softening behaviors of RC piers. The chloride ions corrosion effect for the RC bridges located in coastal areas is considered by using the deterioration model for the mechanical property of reinforcement steel. Besides, structural stability against overturning is considered by incorporating the geometric nonlinearity with the FAM. Since the initial stiffness matrices remain constant through the computation process, the advantages of the FAM, such as high efficiency and stability, are retained. A numerical example is carried out to illustrate the process of seismic performance assessment for offshore RC bridges with the FAM.

scholarly journals Monitoring of a Reinforced Concrete Wharf Using Structural Health Monitoring System and Material Testing

2019 ◽  
Vol 7 (4) ◽  
pp. 84
Author(s):  
Yann Lecieux ◽  
Emmanuel Rozière ◽  
Virginie Gaillard ◽  
Cyril Lupi ◽  
Dominique Leduc ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Concrete Structure ◽  
Chloride Ions ◽  
Temperature History ◽  
Reinforced Concrete Structure ◽  
Structural Health ◽  
Construction Company ◽  
Concrete Shrinkage

This paper presents the Structural Health Monitoring (SHM) system developed for a port wharf of a freight terminal, in Saint-Nazaire, France. This concrete structure has been equipped with a multi-sensor system for the monitoring of concrete ageing. The measurement chain is designed to detect the penetration of chloride ions in order to quantify the risk of reinforcement bars corrosion. Modifications of the mechanical behavior of the structural elements of the wharf are also monitored. At first, the sensors embedded within the structure and the acquisition devices are described. The data from the monitoring performed during the first months of the structure service life are then presented. The concrete monitoring at early age providing data like temperature history, strain and resistivity is useful both for the wharf owner and the construction company since it indicates where concrete shrinkage is likely to cause cracking and gives an indicator of material hardening. These data were compared to the results of material tests carried out on concrete. The study shows that a measurement chain dedicated to the SHM could be a useful tool for validating the quality of the construction of a reinforced concrete structure before being used in the framework of long-term monitoring.

An Experimental Corrosion Investigation of Coupling Chloride Ions with Stray Current for Reinforced Concrete

2012 ◽  
Vol 166-169 ◽  
pp. 1987-1993 ◽  
Author(s):  
Mengcheng Chen ◽  
Kai Wang ◽  
Quanshui Wu ◽  
Zhen Qin
Keyword(s):  
Reinforced Concrete ◽  
Chloride Ion ◽  
Current Strength ◽  
Chloride Ions ◽  
Ion Concentration ◽  
Test Time ◽  
Light Rail ◽  
Stray Current ◽  
Concrete Deterioration ◽  
Two Stages

According to the service environment of light rail transit and subway structures, in this paper experiments on the corrosion characteristics of reinforced concrete under single corrosion environment of stray current, single corrosion environment of chloride ions and joint corrosion environment of stray current and chloride ions were respectively carried out. Loading direct current electric field was used to simulate the stray current. The experimental results showed that, the corrosion growth process of the rebar in reinforced concrete under single environment of chloride ions was slow and stable, while that under single environment of stray current being separated two stages, i.e., rapidly increasing stage and stably varying stage. In addition, the rebar of reinforced concrete in stray current alone environment was corroded faster than that in chloride ion alone environment did; when stray current and chloride ion coexist, the stray current speeded up the chloride ion transportation, which gave rise to the increase of the corrosion rate of the rebar of reinforced concrete; the corrosion degree of the rebar depended on the chloride ion concentration, stray current strength and test time. The stronger the stray current strength, the longer the stray current corrosion period and the heavier the chloride ion concentration, the more the corrosion products of the rebar and thus the more serious the reinforced concrete deterioration.

scholarly journals Durability Investigation of Carbon Fiber Reinforced Concrete under Salt-Freeze Coupling Effect

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6856
Author(s):  
Yongcheng Ji ◽  
Wenchao Liu ◽  
Yanmin Jia ◽  
Wei Li
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fiber ◽  
Coupling Effect ◽  
Chloride Ion ◽  
Chloride Ions ◽  
Fiber Reinforced Concrete ◽  
Ion Concentration ◽  
Fiber Reinforced ◽  
Ion Distribution ◽  
Carbon Fiber Reinforced

In order to study the durability behavior of CFRP (carbon fiber reinforced polymer) reinforced concrete, three category specimens (plain, partially reinforced, and fully reinforced) were selected to investigate its performance variation concerning chlorine salt and salt-freeze coupled environment, which included the microscopic examination, the distribution of chloride ion concentration, and the compressive properties. By observing the microscopic of the specimens, the surface and cross-section corrosion deterioration was examined with increasing exposure time, and the physical behavior of CFRP and core concrete were discussed. The chloride ion diffusion test exerted that the chloride ion concentration in plain specimens is at least 200 times higher than that of fully reinforced specimens. Therefore, the effectiveness of CFRP reinforcement will be proved to effectively hinder the penetration of chloride ions into the core section. The formula of the time-dependent effect of concrete diffusivity with salt-freeze coupling effect was presented and its accuracy verified. A time-varying finite element model of chloride ion distribution was established by using ABAQUS software. It can be seen from the axial compression test that the strength loss rate of three categories of specimens was varied when subjected to the corrosion environment. Therefore, it is proved that CFRP reinforcement can effectively reduce the deterioration of the specimen’s mechanical properties caused by the exposure environment. The research results can provide technical reference for applying the CFRP strengthened concrete in a severe salt-freeze environment.

scholarly journals A review on performance – based specification of durable concrete

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Elson John ◽  
Goldy Prince ◽  
Jessymol George
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Service Life ◽  
Low Cost ◽  
General Assumption ◽  
Chloride Ions ◽  
Actual Structure ◽  
Strength Performance ◽  
Rc Structures ◽  
Performance Specification

Concrete is the most common and widely used building material because of its relatively low cost, flexibility, and adaptability. Recent historical experience indicates that with exposed to aggressive chloride or carbonation-induced conditions, the reinforced concrete (RC) structures deteriorate prior to the expected service life. This is because of the general assumption that the concrete must be sufficiently durable if the strength requirements are adequate. The variability of concrete arising from the actual concreting procedures, such as placement, consolidation, finishing, and curing, does not take this assumption into account. In other words, the concrete cast for compressive strength in the specimens shows no similarity to the concrete in the actual structure. This paper provides a thorough analysis of the advancements that are taking place to achieve the long-term reliability of RC structures based on performance specifications. Keywords: reinforced concrete, service life, compressive strength, performance specification, durability, carbonation, chloride ions

scholarly journals Corrosion studies on XD3 reinforced concrete samples prepared by using calcium nitrate as inorganic corrosion inhibitor with different superplasticizers

2020 ◽  
Vol 64 (1) ◽  
pp. 11-18
Author(s):  
S. A. Abdulsada ◽  
R. Bak ◽  
A. Heczel ◽  
T. I. Török
Keyword(s):  
Reinforced Concrete ◽  
Room Temperature ◽  
Calcium Nitrate ◽  
Inhibition Mechanism ◽  
Test Results ◽  
European Standard ◽  
Corrosion Properties ◽  
Steel Reinforced Concrete ◽  
Corrosion Studies ◽  
Nitrate Anions

AbstractThis research paper presents an analysis of the corrosion properties of steel-reinforced concrete samples during immersion in 3.5 wt. % NaCl aqueous solution by measuring their response both cathodic and anodic polarization in order to determine the corrosion rates in the function of their calcium nitrate inhibitor content. This cheap inorganic inhibitor was added to the concrete mix in concentrations of 1% and 3% by weight of cement in addition to two different superplasticizers (MapeiDynamon SR 31 and Oxydtron). The compressive strengths of the so prepared samples were also checked according to the relevant European standard and were within the acceptable limits, so this inhibitor does not weaken this important property of the concrete samples.The test results on steel reinforced samples immersed in 3.5 wt. % NaCl aqueous solutions at room temperature showed promising corrosion mitigating effects just after 6 months testing period. After 6 months the lower corrosion currents (i.e. better corrosion resistance) for both types of superplasticizers were observed with those samples which contained 3% calcium nitrate inhibitor. The best result was observed with sample C4 (in this case 3% calcium nitrate was added to the mixture of cement+Oxydtron superplasticizer). The advantageous inhibition mechanism of nitrate anions is also discussed and interpreted.

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.

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