• Journal of the Korea Computer Industry Society
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• v.9 no.3
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• pp.137-142
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• 2008

The major influence factor on chloride penetration into concrete structures is chloride ion concentration. In this study, chloride penetration analyses with chloride ion concentration were carried out by the developed program. Also, the service life of concrete structures was predicted. The penetration depth was 32mm in case that chloride ion concentration wad 600ppm. It was shown that the service life of concrete structures with 40mm cover depth was 167 years even though they had been exposed at chloride ion concentration 600ppm during 100 years.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.27-28
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• 2018

Deterioration of reinforced concrete structures due to salt corrosion is a phenomenon that can be easily seen, and the main reason for deterioration is chloride ion. Therefore, researches are actively conducted to control chlorine ion penetration worldwide. The purpose of this study is to evaluate the chloride ion fixation capacity of Portland cement paste containing Hydrotalcite. For this purpose, cement paste containing 0%, 2.5%, and 5% of Hydrotalcite was sealed and cured for 28 days, and the cured cement paste was crushed. Chloride ion solution was prepared at a concentration of 0.5M using NaCl, and the powdered cement paste was reacted for a specific time in aqueous chloride ion solution. After the reaction, the concentration of the chloride ion aqueous solution was measured using a silver nitrate potentiometric titrator, and the reacted cement paste was analyzed using XRD and FT-IR.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.49-50
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• 2022

This study examined the potential of halophilic bacteria in reducing the chloride ion concentration within the cement mortars exposed to chloride attack. As a result of the experiment, the compressive strength of mortar with Halomonas venusta showed an equivalent performance to that of counterpart mortars without bacteria. Also, the chloride ion concentration measured in mortars including Halomonas Venusta was 71% lower than that of the counterpart mortars without bacteria.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.705-710
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• 2003

In this study, to confirm the diffusion coefficient of chloride ion is affected by the concentration of NaCl solution, capacity of voltage, time of an electric current, the diffusion coefficient of chloride ion in concrete was investigated through an electrochemical accelerated test. and the results of these test were compared with the diffusion coefficient of chloride ion by test of sodium chloride solution digestion. As the results of this study, the diffusion coefficient of chloride ion wasn't affected by the concentration of NaCl solution, capacity of voltage, time of an electric current within the range of this study and was similar to the diffusion coefficient of chloride ion by test of sodium chloride solution digestion.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.573-576
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• 2006

To predict service life of concrete structures exposed to chloride attack, surface chloride concentration, diffusion coefficient of chloride ion, and chloride corrosion threshold value in concrete, are used as important factors. of these, as the diffusion coefficient of chloride ion for concrete is strongly influenced by concrete quality and environmental conditions of structures and may significantly change the service life of structures, it is considered as the most important factor for service life prediction. The qualitative factors affecting the penetration and diffusion of chloride ion into concrete are water-binder(W/B) ratio, age, cement type and constituents, chloride ion concentration of given environment, wet and dry conditions, etc. In this paper the influence of cement type on the diffusion characteristics of chloride ion in concrete was investigated through the chloride ion diffusion test. For this purpose, the diffusion characteristics in concrete with cement type such as ordinary portland cement(OPC), binary blended cement(BBC), and ternary blended cement(TBC) were estimated for the concrete with W/B ratios of 32% and 38%, respectively. It was observed from the test that the difussion characteristics of BBC containing OPC and ground granulated blast-furnace slag was found to be most excellent of the cement type used in this study.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.23 no.1
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• pp.11-17
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• 2011

A major source of durability problems in concrete structures is the corrosion of steel by the damage of passivity layer around steel bars. As chloride ion penetration is major cause of the destruction of passivity layer, evaluation of depth and concentration profile of chloride ion is the essential factor for the service-life estimation of concrete structure. To estimate chloride ion penetration characteristics, this paper on the basis of in-situ experimental data investigated the depth and concentration profile of chloride ion penetration. The core specimens are obtained at air-zone, splash zone, and tidal zone in Wando, Masan, Incheon, Gwangyang, and donghae harbors. Colorimentric method measured the chloride ion penetration depth and ASTM C 114 evaluated the concentration profile of chloride ion. Based on experimental data, the influence of harbor location and exposure condition on chloride ion penetration is evaluated.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.225-228
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• 2004

In order to estimate the chloride ion penetration, the model, which considers diffusion and sorption, is proposed on the basis of Finite Element Method (FEM). The FEM program provides the estimation of chloride concentration according to cyclic humidity and sorption. After the humidity diffusion analysis is carried out, the chloride ion diffusion and sorption analysis are conducted on the basis of the preestimated humidity data in each element. Each element has different analysis variables at different ages and locations. At early ages and constant outer humidity, the difference between inner and outer relative humidity causes the chloride ion penetration by sorption. As the humidity diffusion reduces the difference with age, the effect of sorption on the chloride ion penetration decreases. By the way, the cyclic humidity increases the effect of sorption on the chloride ion penetration at early ages, and the quantity of chloride ion around steel at later ages. Therefore, the in-situ analysis of chloride ion penetration for marine concrete structures must be performed considering the cyclic humidity condition and the long term sorption.

• Ocean and Polar Research
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• v.26 no.1
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• pp.43-50
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• 2004

The diffusion model, which considers diffusion and sorption, is proposed. The FEM program developed on the basis of the diffusion model provides the estimation of chloride concentration according to cyclic humidity and sorption. After the humidity diffusion analysis is carried out, the chloride ion diffusion and sorption analysis are conducted on the basis of the preestimated humidity data in each element. Each element has different analysis variables at different ages and locations. At early ages, the difference between inner and outer relative humidity causes the chloride ion penetration by sorption. As the humidity diffusion reduces the difference with age, the effect of sorption on the chloride ion penetration decreases. By the way, the cyclic humidity increases the effect of sorption on the chloride ion penetration at early ages, and the quantity of chloride ion around steel at later ages. Therefore, the in situ analysis of chloride ion penetration for marine concrete structures must be performed considering the cyclic humidity condition and the long term sorption.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.15 no.2
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• pp.71-79
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• 2003

The estimation functions were proposed for calculating diffusion coefficient, chloride binding, and evaporable water. The program estimating chloride ion penetration was developed on the basis of these functions and the effects of humidity, curing temperature, water-cement ratio, and $C_3$A on chloride penetration were analyzed. The relative humidity increases the depth of chloride ion penetration and the trend becomes greater with aging. On the contrary, the influence of curing temperature on chloride ion penetration decreases with aging. By the way, the rise of $C_3$A in cement increases total chloride concentration on the surface as the bound chloride concentration increases but it decreases total chloride concentration on the inner part as the diffusion velocity of free chloride decreases. The fall of water-cement ratio decreases the chloride penetration depth rapidly. Therefore, the reduction of water-cement ratio may be the most effective method for reducing of the steel corrosion by chloride penetration.

• Journal of Environmental Science International
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• v.2 no.4
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• pp.291-297
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• 1993

The COD values and chloride ion concentrations of the Taewha river flowing through Ulsan area were determined along the main stream and the relationships between CODs and chloride ion concentrations were described. The results showed that the middle-upper stream and downstream of the Taewha river were polluted deeply with municipal sewage and self-purification occured in the middle-downstream of the river. When domestic sewage is a main source of pollutants, and is especially the only source of chloride in the stream water, the ratio of COD/[$\textrm{Cl}^{-}$] will be utilizable as a measure of self-purification of the stream.