Penetration of Chlorine Ion in Concrete under the Coupling Effect of the Continues Pressure Load and the Corrosion Environment

2014 ◽  
Vol 633 ◽  
pp. 140-144
Author(s):  
Wei Hong Li ◽  
Ying Ying Xu
Keyword(s):  
Penetration Depth ◽  
Coupling Effect ◽  
Chloride Ion ◽  
Load Level ◽  
Chloride Ions ◽  
Diffusion Method ◽  
Test Time ◽  
Environment Interaction ◽  
Concrete Durability ◽  
Pressure Load

This paper studies the influence law of experiment time, load level under sustained pressure load and the corrosion environment interaction on the permeability of chloride ion in concrete,which is through natural diffusion method. Experimental results show that with the increase of the test time, the penetration depth of chloride ions in concrete and the content of chloride ions in the same penetration depth is growing. As the load level increases, there is a tendency of the chloride ion content after the first increase and then decrease, the turning point in the middle remains to be studied. The research results have a certain significance for concrete durability design and life prediction in corrosion environment.

Experiment Study on Concrete Resistance to Chloride Ion Penetration

2014 ◽  
Vol 716-717 ◽  
pp. 236-239
Author(s):  
Wei Hong Li ◽  
Ying Ying Xu ◽  
Yi Han Wang
Keyword(s):  
Chloride Ion ◽  
Concrete Block ◽  
Load Level ◽  
Diffusion Method ◽  
Environment Interaction ◽  
Ion Content ◽  
Chloride Ion Penetration ◽  
Conservation Condition ◽  
Ion Erosion ◽  
Permeability Of Chloride Ion

The influence law of permeability of chloride ion in concrete of load level, curing condition under the sustained pressure load and the corrosion environment interaction is researched in this article, which is through natural diffusion method. Experimental results show that as the load level increases, there is a tendency of the chloride ion content after the first increase and then decrease, the turning point in the middle remains to be further studied. Good conservation condition reduces large holes and harmful holes in concrete block, thereby reduce the porosity and improve resistance to chloride ion erosion.

The Law of Penetration Research of Chloride Ion in Concrete under Chloride Environment and Sustained Load

2014 ◽  
Vol 1079-1080 ◽  
pp. 374-378
Author(s):  
Wei Hong Li ◽  
Ying Ying Xu ◽  
Chang Long Wu
Keyword(s):  
Chloride Ion ◽  
Concrete Block ◽  
Load Level ◽  
Sustained Load ◽  
Test Time ◽  
Environment Interaction ◽  
Curing Conditions ◽  
Chloride Environment ◽  
Ion Erosion ◽  
Permeability Of Chloride Ion

This paper studies theinfluence law of permeability of chloride ion in concrete of experiment time,load level, curing condition under the sustained pressure load and thecorrosion environment interaction, which is through natural diffusion method.Experimental results show that with the extension of the test time, chlorideion permeability increases. As the load level increases, there is a tendency ofthe chloride ion content after the first increase and then decrease, theturning point in the middle remains to be further studied. Sufficient waterretention curing conditions, making holes in concrete block unhydratedparticles can continue to get the necessary hydration water, thus continuoushydration leads to increased porosity of roughness, but reduces the resistanceto chloride ion erosion.

scholarly journals Experimental Study and Simulation Calculation of the Chloride Resistance of Concrete under Multiple Factors

2021 ◽  
Vol 11 (12) ◽  
pp. 5322
Author(s):  
Yang Ding ◽  
Tong-Lin Yang ◽  
Hui Liu ◽  
Zhen Han ◽  
Shuang-Xi Zhou ◽  
...  
Keyword(s):  
Hydrostatic Pressure ◽  
Penetration Depth ◽  
Chloride Ion ◽  
Cementitious Materials ◽  
Chloride Ions ◽  
Finite Element Software ◽  
Chloride Resistance ◽  
Simulation Calculation ◽  
Marine Concrete ◽  
Resistance Performance

Cement is widely used in marine concrete, and its resistance to chloride ion corrosion has been widely considered. In this paper, based on a laboratory test, the influence of different hydrostatic pressures, coarse aggregate contents and w/c ratios on the chloride resistance performance is analyzed. Based on COMSOL finite element software, a two-dimensional cementitious materials model is established, and the simulation results are compared with the experimental results. The results show that the penetration depth of chloride ions in cement increases with the increase of the w/c ratio. Under the hydrostatic pressure of 0 MPa, when the w/c ratio is 0.35, the penetration depth of chloride ions is 7.4 mm, and the simulation result is 8.0 mm. When the w/c ratio is 0.45, the penetration depth of chloride ions is 9.3 mm, and the simulation result is 9.9 mm. When the w/c ratio is 0.55, the penetration depth of chloride ions is 12.9 mm, and the simulation result is 12.1 mm. Under different hydrostatic pressures, the penetration depth of chloride ions obviously changes, and with the increase in hydrostatic pressure, the penetration depth of chloride ions deepens. Under the w/c ratio of 0.35, when the hydrostatic pressure is 0.5 MPa, the penetration depth of chloride ions is 11.3 mm, and the simulation result is 12.1 mm. When the hydrostatic pressure is 1.0 MPa, the penetration depth of chloride ions is 16.2 mm, and the simulation result is 17.5 mm.

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 Diffusion Behavior of Chloride Ions in Concrete Box Girder under the Influence of Load and Carbonation

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2117
Author(s):  
Yinglong Liu ◽  
Pengzhen Lin ◽  
Junjun Ma
Keyword(s):  
Coupling Effect ◽  
Chloride Concentration ◽  
Chloride Ion ◽  
Chloride Ions ◽  
Ion Concentration ◽  
Scale Model ◽  
Test Results ◽  
Box Girder ◽  
Concrete Box Girder ◽  
The Difference

In order to study the durability degradation characteristics of concrete box girder under load and carbonation and chloride ion erosion, a scale model of concrete box girder was made for experimental research. According to the test results, the diffusion characteristics of chloride ions in the concrete box girder under the coupling effect of load and carbon dioxide were analyzed. By revising the calculation formula of the existing chloride ion concentration considering multiple factors, a calculation model of chloride ion concentration considering the influence of carbonation was proposed, and the test results were verified. The results show that the chloride concentration of the box girder on the same cross section is non-uniformly distributed due to the shear lag effect and the spatial structure. After considering the effect of carbonation, the difference rate of the improved model proposed in this paper is generally within 10%. Compared with the original model, the difference rate is reduced by a maximum of 19%.

scholarly journals Protective Mechanism of Silane on Concrete upon Marine Exposure

Coatings ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 558 ◽  
Author(s):  
Shaochun Li ◽  
Wenjuan Zhang ◽  
Jun Liu ◽  
Dongshuai Hou ◽  
Yongjuan Geng ◽  
...  
Keyword(s):  
Permeability Coefficient ◽  
Sol Gel ◽  
Synthesis Method ◽  
Chloride Ion ◽  
Chloride Ions ◽  
Ion Concentration ◽  
Test Block ◽  
Protective Mechanism ◽  
Concrete Durability ◽  
Protective Effects

Due to the high chloride ion concentration in marine environments, chloride ions can penetrate into concrete, along with the transportation of water molecules, and thus, cause rebar corrosion. This is an important reason for the decrease in the concrete durability. In this paper, by means of the sol–gel synthesis method, a silane emulsion, a silane compound emulsion, and silane compound gel were prepared by using isobutyl triethoxysilane and ethyl orthosilicate (TEOS) as the main raw materials. These silane materials were coated on a concrete surface and then placed in the marine exposure sites of Wheat Island, in Qingdao, for one year. The results show that these silane materials can effectively inhibit the chloride ions transporting in concrete. Upon the increase of the exposure time, the protection ability of the silane emulsion declined gradually, while the silane compound emulsion had stable protective effects. In comparison with the permeability coefficient of chloride ions in the blank test block, the permeability coefficient of chloride ions in the test block coated with the silane emulsion, the composition of silane emulsion, and silane compound gel fell off around 20%, 30%, and 50%, respectively. The test results indicate that the three kinds of protective materials have good inhibition abilities against chloride ion transportation, on which the compound gel had the best effect.

Test Research of Chloride Ion Penetration in Concrete Tunnel Lining Structure

2012 ◽  
Vol 446-449 ◽  
pp. 3155-3159
Author(s):  
Zhong Li ◽  
Yan Peng Zhu ◽  
Xiao Yan Cui
Keyword(s):  
Service Life ◽  
Penetration Depth ◽  
Chloride Ion ◽  
Chloride Content ◽  
Chloride Ions ◽  
Tunnel Lining ◽  
Chloride Ion Penetration ◽  
Lining Structure ◽  
Erosion Environment ◽  
Ion Penetration

Chloride ion diffusion coefficient is an important indicator reflected the concrete durability in chloride erosion environment, and affects the service life of concrete structure directly. By the indoor test of chloride acceleration permeability, the chloride ions diffusivity is studied in the tunnel lining structure, and the variation law of the chloride content is tested with the change of penetration depth of different age specimen. Tests shows, with the increases of the penetration depth, the chloride content decrease gradually and finally tend to the initial chloride content of the specimen. Penetration time has a strong cumulative effect on the internal concentration of chloride ions in concrete, the high or low level of chloride ion concentration have a role of promotion or reduction for the chloride ion penetration in the concrete inside. The results provide an important basis for the predictions of service life of tunnel lining in chloride erosion environment.

Experimental Study on Improvement Mechanism of Silane Emulsion on Acid Rain Corrosion of Green Ecological Concrete

2020 ◽  
Vol 12 (6) ◽  
pp. 873-883
Author(s):  
Wei Xun Hu ◽  
Yao Zhuang Li ◽  
Hua Peng
Keyword(s):  
Compressive Strength ◽  
Service Life ◽  
Acid Rain ◽  
Concrete Structure ◽  
Test Group ◽  
Chloride Ion ◽  
Chloride Ions ◽  
Test Time ◽  
Ratio Test ◽  
Mixing Ratio

Concrete structure is vulnerable to acid rain corrosion, which affects the service life of the material, in the corrosive environment, and concrete structure will deteriorate because of the erosion of water/chloride ions. Therefore, waterproof treatment of concrete structure is needed to improve the durability of the structure. In this study, the green ecological concrete is taken as the research object. The concrete is mixed with a certain amount of silane emulsion to reduce the probability of corrosion of concrete due to moisture and chloride ions, thereby prolonging the service life of this kind of concrete. During the experiment, in order to further test the corrosion resistance of silane emulsion to this kind of concrete, different kinds of concrete were taken as test objects and divided into 3 test groups, namely, the original test group (ITE), the non silane emulsion test group (TWSE) and the optimal ratio test group (OT-SE). It is proved by experiments that the best proportion of concrete mixed with silane emulsion is 0.32 of water binder ratio, 18% of coal powder mixing ratio, 37% of gravel mixing ratio and 0.23% of proportion of silane emulsion. The above factors are applied to compressive strength test, and 30 days as test time, the compressive strength of concrete with fly ash is measured. In the experiment of anticorrosion, compared with the traditional concrete samples, the electrical flux of concrete mixed with silane emulsion decreased by 28.7% in 8 h, that is, chloride ion permeability decreased significantly.

scholarly journals Chloride Ion Corrosion Pattern and Mathematical Model for C60 High-Strength Concrete after Freeze-Thawing Cycles

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Yan Li ◽  
Bing Li ◽  
Lian-ying Zhang ◽  
Chao Ma ◽  
Jiong Zhu ◽  
...  
Keyword(s):  
Mathematical Model ◽  
High Strength Concrete ◽  
Chloride Ion ◽  
High Strength ◽  
Chloride Ions ◽  
Diffusion Method ◽  
Freeze Thaw ◽  
Strength Concrete ◽  
Artificial Environment ◽  
Transport Control

In this study, the porosities of C60 high-strength concrete after 0, 30, 60, and 90 freeze-thaw cycles determined via the water retention method are 1.30%, 3.65%, 5.14%, and 7.34%, respectively. Furthermore, a mathematical model of porosity varying with the number of freeze-thaw cycles is established. Using an artificial environment simulation experimental system and the natural diffusion method, the chloride diffusion law of C60 high-strength concrete after 0, 30, 60, and 90 freeze-thaw cycles is obtained. The corresponding diffusion coefficients are calculated based on the experimental results and Fick’s law, where 0.3431 × 10−12, 0.5288 × 10−12, and 0.6712 × 10−12, and 0.8930 × 10−12 m2/s are obtained, respectively, and a mathematical model of diffusion coefficient with freeze-thawing is established. Transport control equations comprising solution flow and solute migration control equations are established for chloride ions in concrete after freeze-thawing cycles. The equations consider the effects of freeze-thawing, solution pressure, solution concentration, solution density, convection, mechanical dispersion, and chemisorption on chloride ion transport in concrete. Using COMSOL numerical software, the transport control equations for chloride ions are solved using a real concrete numerical model, and the chloride ion corrosion process in concrete after freeze-thaw cycles is simulated. The simulation results are consistent with the experimental values.

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