Experimental Study on the Corrosion Law of Chloride in Concrete under Artificial Climate

2013 ◽  
Vol 405-408 ◽  
pp. 2520-2523
Author(s):  
Yi Wan ◽  
Zhi Wu Yu ◽  
Peng Liu ◽  
Yu Yan Sun
Keyword(s):  
Experimental Study ◽  
Diffusion Coefficient ◽  
Diffusion Coefficients ◽  
Convection Zone ◽  
Concrete Strength ◽  
Chloride Ion ◽  
Concrete Surface ◽  
Ion Diffusion ◽  
Different Depths ◽  
Chloride Ion Diffusion

Corrosion experimental were conducted in order to study concrete samples of two strength grades during different erosion period under the condition of designed artificial chloride erosion.Through drilling powder of concrete surface at various depths,chloride ions’concentration at different depths of corroded samples were determinated,and the diffusion coefficients of chloride ion after 90,180,240 days of corrosion were calculated on the basis of Fick’s second law.It turns out that obvious convection zone exitsin corroded concrete,and the thickness of convection zone increases with the erosing time and the reduction of concrete strength grade.In addtion,fitted datas of chloride ion diffusion coefficient increases with the reduction of concrete strength grade.

The Effect of Surface Hydrophobation Silane Treatment on Chloride Ion Penetration Resistance for Concrete Structures in Marine Environments

2012 ◽  
Vol 598 ◽  
pp. 524-530
Author(s):  
Hai Cheng Yang ◽  
Zhao Zhong Wang ◽  
Jian Bo Xiong
Keyword(s):  
Convection Zone ◽  
Chloride Concentration ◽  
Chloride Ion ◽  
Concrete Surface ◽  
Ion Diffusion ◽  
Exposure Test ◽  
Wetting And Drying ◽  
Chloride Ion Penetration ◽  
Chloride Ion Diffusion ◽  
Effect Of Surface

Effect of concrete surface hydropobation treatment against chloride penetration have been studied by in-site exposure test. The results show that the silane impregnated layer can prevent the chlorides penetration into the concrete substrate effectively, reduce the apparent chloride ion diffusion coefficient and surface chloride concentration, and improve the service life of concrete structure; and the depth of concrete convection zone can reduce due to silane impregnated layer for concrete in the marine environment of wetting and drying area.

Experimental Study on Mix Design of Chloride Resistant Cementitious Spacers

2014 ◽  
Vol 629-630 ◽  
pp. 351-357
Author(s):  
Chen Huang ◽  
Wen Ying Guo ◽  
Yi Bo Yang ◽  
Hui Zhao ◽  
Zhen Jie Li ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Design Method ◽  
Chloride Ion ◽  
Chloride Ions ◽  
Mix Design ◽  
Easy Access ◽  
Ion Diffusion ◽  
Electric Flux ◽  
Chloride Environment ◽  
Chloride Ion Diffusion

Chloride resistant HPC and protective cover are two basic measurements to improve the durability of concrete in chloride environment. Though it provides crucial cover for concrete to resist chloride ions, spacer has limited chloride resistant ability, which is overlooked by past researchers. Cementitious spacers are easy access for chloride ions to penetrate into concrete resulting in reduction of structural durability. To improve cementitious spacers’ performance, a systematic study was conducted. Test results showed that there was major difference between mortar and concrete in terms of chloride coulomb electric flux but minor difference in terms of chloride ion diffusion coefficient, which implied using chloride ion diffusion coefficient as spacer’s durability indicator was preferable; parameters of mix design had a similar influence on mortar and concrete and, with the same mixing parameters, the strength and chloride resistant ability of mortar were weaker than concrete’s; it was feasible to develop the mix design of chloride resistant cementitious spacers based on concrete’s design method with certain adjustments, such as using stricter mix proportion, adding small-size coarse aggregate, lowering water-binder ratio and optimizing the binder proportion, to achieve higher strength and durability.

scholarly journals Evaluation of Chloride-Ion Diffusion Characteristics of Wave Power Marine Concrete Structures

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5675
Author(s):  
Changhyuck Lim ◽  
Gyuyong Kim ◽  
Gyeongtae Kim ◽  
Bokyeong Lee ◽  
Youngduck Kim ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Atmospheric Pressure ◽  
Concrete Structures ◽  
Chloride Ion ◽  
Wave Power ◽  
Ion Diffusion ◽  
Chloride Ion Penetration ◽  
Chloride Attack ◽  
Marine Concrete ◽  
Chloride Ion Diffusion

Wave power marine concrete structures generate electrical energy using waves. They are exposed to a multi-deterioration environment because of air and hydrostatic pressure and chloride attack. In this study, the effect of air pressure repeatedly generated by water level change of wave power marine concrete structures on the chloride-ion diffusion of marine concrete was analyzed. The chloride-ion diffusion of wave power marine concrete structures was evaluated. The results show that the air chamber and bypass room, which were subjected to repetitive air pressures caused by water level changes, showed a higher water-soluble chloride-ion content compared to the generator room and docking facility, which were subjected to atmospheric pressure. Field exposure tests and indoor chloride attack tests were performed using fabricated specimens to analyze the effect of pressure on chloride-ion penetration. It was confirmed that Portland blast furnace slag had a greater inhibitory effect on chloride-ion penetration than ordinary Portland cement. The concrete specimens subjected to pressure showed increased capillary pores and micro-cracks. We devised an equation for calculating the diffusion coefficient based on measured data and estimating the diffusion coefficient for the location receiving repeated air pressure by using the diffusion coefficient of the location receiving general atmospheric pressure.

scholarly journals Experimental Study on Chloride Ion Diffusion in Concrete under Uniaxial and Biaxial Sustained Stress

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5717
Author(s):  
Xiaokang Cheng ◽  
Jianxin Peng ◽  
C.S. Cai ◽  
Jianren Zhang
Keyword(s):  
Diffusion Coefficient ◽  
Compressive Stress ◽  
Stress Level ◽  
Chloride Concentration ◽  
Chloride Ion ◽  
Chloride Ions ◽  
Chloride Diffusion ◽  
Chloride Diffusion Coefficient ◽  
Ion Diffusion ◽  
Chloride Ion Diffusion

The existence of axial and lateral compressive stress affect the diffusion of chloride ions in concrete will lead to the performance degradation of concrete structure. This paper experimentally studied the chloride diffusivity properties of uniaxial and biaxial sustained compressive stress under one-dimensional chloride solution erosion. The influence of different sustained compressive stress states on chloride ion diffusivity is evaluated by testing chloride concentration in concrete. The experiment results show that the existence of sustained compressive stress does not always inhibit the diffusion of chloride ions in concrete, and the numerical value of sustained compressive stress level can affect the diffusion law of chloride ions in concrete. It is found that the chloride concentration decreases most when the lateral compressive stress level is close to 0.15 times the compressive strength of concrete. In addition, the sustained compressive stress has a significant effect on chloride ion diffusion of concrete with high water/cement ratio. Then, the chloride diffusion coefficient model under uniaxial and biaxial sustained compressive stress is established based on the apparent chloride diffusion coefficient. Finally, the results demonstrate that the chloride diffusion coefficient model is reasonable and feasible by comparing the experimental data in the opening literature with the calculated values from the developed model.

The Effect of Superplasticizer on Strength and Chloride Permeability of Concrete Containing GGBFS

2013 ◽  
Vol 804 ◽  
pp. 12-16 ◽  
Author(s):  
Shi Yi Zhang ◽  
Ying Fang Fan ◽  
Ning Ning Li
Keyword(s):  
Mechanical Property ◽  
Compressive Strength ◽  
Diffusion Coefficients ◽  
Chloride Ion ◽  
Ion Diffusion ◽  
Chloride Permeability ◽  
Additive Content ◽  
Chloride Ion Penetration ◽  
Chloride Ion Diffusion

The effect of superplasticizer on the mechanical property and chloride permeability of concrete containing GGBFS is investigated in this paper. Compressive and rapid chloride-ion diffusion tests were conducted to determine the axial compressive and chloride-ion diffusion coefficients of GGBFS modified concrete. The tests result indicated that the compressive strength of GGBFS modified concrete with the addition of 2wt. % superplasticizer are further improved at 14 and 28 days. Superplasticizer can significantly enhance the resistance to chloride ion penetration of concrete containing GGBFS with a reasonable additive content at long-term age. The optimum content of superplasticizer is suggested to be 1wt. % to 2wt. % of the cementitous materials.

Influence of Concrete with Lithium-Slag and Steel Slag by early Curing Conditions

2014 ◽  
Vol 599 ◽  
pp. 52-55 ◽  
Author(s):  
Fu Fei Wu ◽  
Ke Bin Shi ◽  
Shuang Kuai Dong
Keyword(s):  
Diffusion Coefficient ◽  
Water Conservation ◽  
Water Solution ◽  
Steel Slag ◽  
Chloride Ion ◽  
Ion Diffusion ◽  
Binder Ratio ◽  
Water To Binder Ratio ◽  
Lithium Slag ◽  
Chloride Ion Diffusion

Using industrial waste (lithium-slag and steel-slag) for the preparation of high-performance concrete, and the same mix proportion’s concrete are cured using six kinds method, which is cured to the required age later and tests its chloride ion diffusion coefficient by RCM method. The results show that: the chloride ion diffusion coefficient of 28d and 84d decreases with the lower water-binder ratio. It can achieve RCM-Ⅴ grade when the water to binder ratio is 0.27. The admixtures total of 275-350kg/m3 is appropriate when the water to binder ratio is constant.The diffusion of water conservation,water solution with 5% Nacl after 7d water conservation,water solution with 5% Nacl after 14d water conservation,water solution with 5% Nacl after 7d in water conservation and water solution with 5% Nacl after 14d in water conservation is 1.5, 3.1, 2.5, 2.8 and 2.3 times than standard conservation , so the effect of early different curing ways to HPC can not be ignored.

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