• International Journal of Highway Engineering
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• v.15 no.2
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• pp.29-37
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• 2013

PURPOSES : This study aims to review the possibility of developing a road snow-melting system that can prevent slip accidents by maintaining a constant temperature of the winter roads and enhance performance of structures, including improvement of compressive strength by mixing carbon nanotube (hereafter referred to as CNT) with cement paste, the basic material. METHODS : To achieve the above purpose, an experiment was conducted by mixing power-type CNT and wrap-type CNT up to cement paste formulation by weight of 0.0wt%~4.1wt% in accordance with "KS L ISO 679(of cement strength test method)", and compressive strength was measured at 28 days of curing. In addition, the volume resistivity of the specimen was measured to test thermal and electrical characteristics, and the rate of temperature changes in specimen surface by power consumption was measured by passing electricity through the cross-sections of the specimen. Meanwhile, the criteria for checking the performance as a road snow-melting system was determined as volume resistivity of $100{\Omega}{\cdot}cm$ or less. RESULTS : A comparative analysis between specimen with 0wt% CNT content in plain status and specimen containing various types of CNTs was carried out. From its results, it was found that compressive strength increased approximately 19%, showing the highest rate when 0.2wt% of wrap-type CNT was contained, but volume resistivity of $100{\Omega}{\cdot}cm$ or less appeared only in specimens containing more than 0.2wt% CNT. In addition, it was observed that the surface temperature increased by $4.62^{\circ}C$ per minute on average in specimens containing 3.2wt% CNT. CONCLUSIONS : In this study, CNT was examined as an underlying material for a road snow-melting system, and the possibility of developing the road now-melting system was reviewed by conducting various experiments using CNT-Cement composites. From the experimental results, the specimens were found to have a superior performance when compared to the existing road snow-melting systems that place the heat transfer medium such as copper on the road. However, satisfactory strength performance were not obtained from the specimen containing CNT(2.0% or more) that functions as a heating element, which leads to the need for reviewing methods to increase the strength by using plasticizer or admixture.

• Journal of Korean Institute of Industrial Engineers
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• v.37 no.4
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• pp.415-420
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• 2011

Snow removal system is named for machinery which manages roads for passing of pedestrians and automobiles when snow is piled up on the road. This paper studies configuration design of snow removal system that has several functions-melting snow in the street without moving it to other place, transferring snow to the melter and cleaning road by spraying water for cleaning road. These sorts of functions are analyzed by function decomposition method of Kirshman and Fadel and, based upon which, machine parts are selected. Layout design would follow functional design to testify if the selected component satisfies space which is allowed by constraints.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.5 no.3
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• pp.226-233
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• 1993

Thermosyphons are simple devices that can passively transport thermal energy over relatively large distance with little temperature degradation. Especially, the thermosyphon system requires no costly energy input and is completely maintenance free. These attributes permit the use of low grade thermal energy for thermal control of structures including the stabilization of highway foundations. This paper presents the experimental results of the snow melting system in which thermosyphon was utilized to ransfer the earth energy to the pavement to remove snow and ice. The test facility, three earth heated and one unheated test panels, is designed to investigate the variables associated with removing snow and ice from pavement surfaces. The results of these test show that the earth heated panel surface temperature is higher $2{\sim}6^{\circ}C$ than unheated panel when the ambient air temperature is $-7^{\circ}C$. The thermal performance of this earth source thermosyphon system for road heating showed that there was no snow on the heated test panels when the snowfall was 5cm average for the region.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.44 no.4
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• pp.362-369
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• 2008

The snow melting system by electric heating wires which is adopted in this research is a part of road facilities to keep surface temperature of the road higher than freezing point of water for melting the snow accumulated on it. The electric heating wires are buried under paved road at a certain depth and operated automatically and manually. Design theory, amount of heating, and installation standard vary according to economic situation, weather condition, installation place and each country applying the system. A main purpose of this study is figuring out the appropriate range of required heat capacity and installation depth and pitch for solving snowdrifts and freezing problems with minimum electric power consumption. This study was performed under the ambient air temperature($-2^{\circ}C$, $-5^{\circ}C$), the pitches of the electric heating wires(200 mm, 300 mm), heating value($250\;W/m^2$, $300\;W/m^2$, $350\;W/m^2$).

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.3
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• pp.45-52
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• 2010

The relationship between climate changes and transportation could be separated by two approaches. One of methods was to find how climate changes affected transportation, and the other way was how transportation affected climate changes. In this study, we reported from the former standpoint, how climate changes affected transportation fields. When there is a lot of snowfall in Seoul, it starts ripple effect through the travel patterns. They can be explained by travel time and operating cost. The travel costs were calculated in this paper for analysing the effect of disbenefit by climate changes. Snow Melting System was also studied for relieving negative influences under the unpredictable weather condition. As a result, the system was effective for minimizing disbenefit by climate changes.

• International Journal of Highway Engineering
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• v.15 no.2
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• pp.19-27
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• 2013

PURPOSES : This study aims to investigate the snow-melt effects of an underground electric heater's snow-melt system via a field performance test, for evaluating the suitability of the system for use on a concrete pavement. The study also investigates the effectiveness of dynamic measures for clearing snow after snowfall events. METHODS : In order to check the field applicability, in November 2010, specimens were prepared from materials used for constructing concrete pavements, and underground electric heating meshes (HOT-mesh) were buried at depths of 50 mm and 100 mm at the site of the Incheon International Airport Construction Research Institute. Further, an automatic heating control system, including a motion sensor and pavement-temperature-controlled sensor, were installed at the site; the former sensor was intended for determining snow-melt effects of the heating control system for different snowfall intensities. Pavement snow-melt effects on snowy days from December 2010 to January 2011 were examined by managing the electric heating meshes and the heating control system. In addition, data on pavement temperature changes resulting from the use of the heating meshes and heating control system and on the dependence of the correlation between the outdoor air temperature and the time taken for the required temperature rise on the depth of the heating meshes were collected and analyzed. RESULTS : The effects of the heating control system's preheat temperature and the hot meshes buried at depths of 50 mm and 100 mm on the melting of snow for snowfalls of different intensities have been verified. From the study of the time taken for the specimen's surface temperature to increase from the preheat temperature ($0^{\circ}C$) to the reference temperature ($5{\sim}8^{\circ}C$) for different snowfall intensities, the correlation between the burial depth and outdoor air temperature has been determined to be as follows: Time=15.10+1.141Depth-6.465Temp CONCLUSIONS : The following measures are suggested. For the effective use of the electric heating mesh, it should be located under a slab it may be put to practical use by positioning it under a slab. From the management aspect, the heating control system should be adjusted according to weather conditions, that is, the snowfall intensity.

• International Journal of Highway Engineering
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• v.17 no.5
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• pp.1-10
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• 2015

PURPOSES : A finite difference model considering snow melting process on porous asphalt pavement was derived on the basis of heat transfer and mass transfer theories. The derived model can be applied to predict the region where black-ice develops, as well as to predict temperature profile of pavement systems where a de-icing system is installed. In addition, the model can be used to determined the minimum energy required to melt the ice formed on the pavement. METHODS : The snow on the porous asphalt pavement, whose porosity must be considered in thermal analysis, is divided into several layers such as dry snow layer, saturated snow layer, water+pavement surface, pavement surface, and sublayer. The mass balance and heat balance equations are derived to describe conductive, convective, radiative, and latent transfer of heat and mass in each layer. The finite differential method is used to implement the derived equations, boundary conditions, and the testing method to determine the thermal properties are suggested for each layer. RESULTS: The finite differential equations that describe the icing and deicing on pavements are derived, and we have presented them in our work. The framework to develop a temperature-forecasting model is successfully created. CONCLUSIONS : We conclude by successfully creating framework for the finite difference model based on the heat and mass transfer theories. To complete implementation, laboratory tests required to be performed.

• Journal of Korean Society of societal Security
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• v.3 no.1
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• pp.43-50
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• 2010

Sliding accidents on the road have a high percentage by road freezing, especially, they often have appeared at bridges and Tunnel of freezing areas. Thus, the stability of road operations is enhanced by preventing partial freezing phenomenon. According to the geothermal snow melting system analysis, a pattern of thermal conductivity is found out; pavement materials of concrete and asphalt where the system is buried. The heat transfer simulation is essential when the geothermal snow melting system is applied according to heating exchanger pipe placed in the lower pavements. The model tests are conducted on low temperature in freezer using the manufactured test model which is equal to pavement materials. Many variables are discovered from numerical analyses under the same conditions with model test.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09b
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• pp.1086-1087
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• 2005

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.6 no.2
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• pp.23-28
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• 2010

Fluent ver.6.3 is used as CFD(Computational Fluid Dynamics) simulator to predict the performance of snow-melting system by geothermal pipes energy. As the results of this simulation, it is clearly shown that $50^{\circ}C$ of working fluid in to geothermal evaluated as more effect comparing to $45^{\circ}C$ of working fluid. The Surface temperature is come to $5^{\circ}C$ at 1m/s speed and $50^{\circ}C$ temperature of the working fluid.