• Journal of the Korean GEO-environmental Society
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• v.20 no.4
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• pp.31-38
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• 2019

Field tests with carbon fiber heating wire (CFHW) embedded inside concrete slab were performed to present the alternative heating material capable of avoid the adverse effects of traditional de-freezing salt on the structures and environment. The CFHW was inserted into the concrete slab in the shape of 'ㄷ' to improve the heat superposition and the temperature on the surface was measured using iButton. The results showed that the temperature where the CFHW's were faced with each other increased to above zero after 12-hour at outdoor air temperature of $-6^{\circ}C$. Comparatively, the temperature slightly increased where the CFHW was embedded on one side because the heat was not superimposed. Hence, it can be said that the CFHW is a suitable heating material to prevent the concrete road from being frozen.

• Journal of the Korea Concrete Institute
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• v.17 no.5 s.89
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• pp.743-750
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• 2005

High performance concrete containing silica fume for use in bridge deck overlay emerged as a viable type of bridge deck overlay that economic advantage in construction. They have gained acceptance in Europe, America and Canada in a relatively short time due to their low cost. In this study, high-performance concretes containing silica fume were tested and evaluated in the laboratory to assess their applicability for use in bridge deck overlay. It was conducted with experiments of mechanical and durability characteristics in compressive strength, flexural strength, chloride permeability, abrasion resistance, repeated freezing and thawing cycles and deicing salt scaling resistance. Laboratory test result describe that high-performance concrete containing silica fume for bridge deck overlay application shows most outstanding capacity.

• Journal of Environmental Science International
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• v.26 no.9
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• pp.1081-1086
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• 2017

The present study was conducted for the purpose of analyzing the growth response of Dracaena braunii treated with chloride ions and to evaluate its salt tolerance. Distilled water (CON) was spiked with 1 (C1), 2 (C2), 5 (C5), 10 (C10) and 15 g/L (C15) $CaCl_2$, respectively. Acidity (pH) and electrical conductivity of hydroponic solution, and leaf width, leaf length, root length, number of leaves, fresh weight, dry weight and the water content of Dracaena braunii were measured. Acidity and electrical conductivity remarkably increased commensurate with increasing concentrations of $CaCl_2$. Growth in the C1 treatment was better than that in CON, whereas the C10 or C15 treatments caused either slow growth or withering of the plants. Fresh weight, dry weight and water content were significantly decreased in response to $CaCl_2$ concentration, compared with those in the control. These results showed that $CaCl_2$ concentration less than 1 g/L may be used as a hydroponic solution for D. braunii, as long as the water quality is not too saline. The chlorine ion has a negative effect on the growth.

• Journal of Environmental Science International
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• v.26 no.8
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• pp.993-998
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• 2017

De-icing salts applied to roads during winter enable safe driving conditions. However, these salts are eventually displaced to roadside areas at which they can negatively impact soil, vegetation, and water resources. This purpose of this study is to determine the relationship between foliar damage ratio (NY = 0-25%, SY = 26-50%, CY = 51-75%) on roadside trees (Ginko biloba) and seasonal impact of de-icing salts on soil and vegetation. Thirty roadside trees were selected at 8 m intervals between the Konkuk and Judeok intersections in Chung-ju city. The results reveal that seasonal soil acidity is relatively alkaline for foliar damage ratio of Ginko biloba was CY compared to NY. Also, electronic conductivity of each seasonal sampling was recorded as high in winter and spring, whereas the opposite trend is observed in summer. Various plants species were identified in abundance under roadside trees within NY roadside sections. These same species were observed in reduced numbers within CY sections. Strong negative correlations were identified between foliar damage ratio on roadside trees and vegetation. This relationship may be a method to use in predicting the accumulation of de-icing salt and visible injuries on roadside trees.

• International Journal of Highway Engineering
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• v.17 no.1
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• pp.35-41
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• 2015

PURPOSES : The purpose of this study is to analyze the service life of expressway pavement based on both traffic volumes and use of deicing chemicals. METHODS : A database was built using expressway rehabilitation history information from over the last decade. In order to estimate the service life of expressway pavement, various analysis methods were considered, and a decision was made to perform analysis using a method based on an accumulated rehabilitation ratio. The service life of expressway pavement was then analyzed by classifying the scale of traffic volume and extent of de-icing chemicals used. RESULTS : The service life of PMA and SMA ranged from 7.8 to 10.6 years and from 9.9 to 12.0 years, respectively. The service life of JCP ranged from 16.0 to 22.2 years, and the service life of CRCP was 33.5 years on average. Results of assessing service life according to traffic volumes and de-icing chemicals showed that the lower the traffic volumes were, the greater the service life of PMA and JCP, and the less that de-icing chemicals were applied, the greater the service life of JCP. CONCLUSIONS : The dependence of expressway pavement service life on traffic volumes and de-icing chemicals makes it possible to apply LCCA for regional maintenance plans and cost-effective selection of expressway pavement type.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.3
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• pp.30-38
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• 2015

In cold-climate regions, deicing agents is used for smooth traffic on the road due to freezing and snowdrift in winter. The use of de-icing salts has resulted in the accelerated scaling damage of concrete with salt damage under freezing and thawing condition. Scaling is the deterioration of concrete where in the paste-mortar structure delaminates in flakes from the surface of the concrete. Due to such damage, concrete pavement causes various problems such as early deterioration according to the decrease in the thickness of cover concrete and user's stability issues. Accordingly, various tests and evaluation methods have been suggested in order to evaluate these phenomena in other countries. However, there have been no regulations for the evaluation method in South Korea, and related studies are also very rare. Therefore, in this study, the evaluation methods proposed by each institution and country were investigated and the experiments were performed according to each regulation, followed by the comparison and analysis of the results. Furthermore, this study aims to suggest the optimized experimental method adopted to domestic field through the discussion of such experimental methods and results.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.565-568
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• 2008

Domestic area of most be happened chloride deicer damage. Because daily mean temperature is below 0$^{\circ}C$ from the area of domestic most. Concrete durability influence Air Content. Presently, We used to AE(air-entraining agent) for increase freeze-thaw durability. So, on concrete Air Spacing ratio used $200{\mu}m{\sim}230{\mu}m$ in Canada and under $250{\mu}m$ in Japan institution. Use of Air content has been and will continue to be a major part of concrete durability and scaling. Chloride-containing chemicals such as calcium chloride or rock salt are main deicers for the road. The prepared optimum mix concrete in this study show that freeze-thaw and scaling resistance of Non-AE(air content 1.5%) and AE (air content 4.5%, 7.2%). Solution concentrations of deicing agent were good result, and the pore system and change of hydration products is not difference comparing before freeze-thaw test.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.1
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• pp.111-118
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• 2016

The scaling of concrete caused by the combined effects of frost and deicing salt is one of the principle causes of damage to transportation infrastructure in cold-climate regions. In this study, to evaluate the factors affecting scaling resistance of concrete, the relationship between the properties of concrete, such as the mechanical properties and pore structure, and scaling resistance was examined experimentally. The test results showed that the scaling resistance was strongly dependent on the absorption properties of concrete, but not on the compressive strength. Furthermore, it is believed that both the spacing factor and specific surface of the air voids was not a good parameter for evaluating the scaling resistance of concrete. SGC concrete was less durable than OPC and SFC concrete with respect to the scaling resistance in the scope of the present study.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7917-7924
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• 2015

In this study, based on CMA which is increasingly used for eco-friendly deicing materials, dehumidification MB made of sodium carbonate, $MgCl_2$/MgO (M/M), and SAP is to be produced. And its moisture absorption rate and dehumidification performance of the film are to be analyzed. And the data on the materials used for the dehumidification film are to be acquired. In case of the dehumidification MB, in which CMA and SAP are mixed, had poor film machinability due to foaming and moisture issues, but adding bentonite and calcium carbonate solved the problem. When a foaming agent was added to extend surface area between substances, CMA and M/M showed no remarkable difference, but SC showed large increase to 3.15 g/g. As the result of anti-corrosive test, CMA dehumidification film showed no corrosion while SC showed pitting corrosion and M/M showed corrosion.

• Smart Structures and Systems
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• v.29 no.5
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• pp.653-660
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• 2022

Gravel scattering that is generated during operation of high-speed railway vehicle is cause to damage of vehicle such as windows, axle protector and so on. Especially, those are frequently occurred in winter season when snow ice is generated easily. Above all, damage of vehicle windows has not only caused maintenance cost but also increased psychological anxiety of passengers. Various methods such as heating system using copper wire, heating jacket and heating air are applied to remove snow ice generated on the under-body of vehicle. However, the methods require much run-time and man power which can be low effectiveness of work. Therefore, this paper shows that large-area heating system was developed based on heating coat in order to fundamentally prevent snow ice damage on high-speed railway vehicle in the winter season. This system gives users high convenience because that can remotely control the heating system using IoT-based wireless communication. For evaluating the applicability to railroad sites, a field test on an actual high-speed railroad operation was conducted by applying these techniques to the brake cylinder of a high-speed railroad vehicle. From the results, it evaluated how input voltage and electric power per unit area of the heating specimen influences exothermic performance to draw the permit power condition for icing. In the future, if the system developed in the study is applied at the railroad site, it may be used as a technique for preventing all types of damages occurring due to snow ice in winter.