• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.98-99
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• 2020

The objective of the study is to investigate the compressive strength of damaged part by early frost damage and sound part of the concrete placed when exposed to a low temperature of -20℃ for 24 hours in normal concrete. Test results indicated that the compressive strength of damaged part was 14.5 MPa lower than that of sounf part due to early frost damage.

• Review of Korea Contents Association
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• v.12 no.4
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• pp.47-50
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• 2014

• Magazine of the Korean Society of Agricultural Engineers
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• v.32 no.3
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• pp.39-46
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• 1990

This paper was analized the thermal conductivity of polystylene (TENSAR- GEOGRID) embeding into the subbase through frost penetration depth, frost heave, change of bearing capacity, and soil moisture movement due to freezing, thawing and icing actions, and their results were as follows : 1.The change of temperature into the sub-base was much increased by the Tensar-Geogrid insertion, and the frost penetration and frost heave were decreased as the thinner of the insulation thickness but the thawing velocity of melting period was appeared to be faster in case of non-insulated. 2.The frost heave had a close relationship with the thickness of insulations which was reasonably included anti-frost effects. 3.The moisture content during the freezing period of upper layer of the insulation insertion was increased by 15 per cent but it was returned to initial state of the thawing period, and at the down layer temporarily increased by 10 per cent and returned to the original state at once. 4.The insulation was acted as a function of distribution of surcharge, and the settlement of the sub-base was about 1.5 mm under 15 tonnage of load and which was included within the allowable limits. 5.The sliding resistance due to the icing which was induced by the insulation insertion into the sub-base was appeared as more 40 per cent than noninsulation area, so that the insulations should be restricted on the place such as mountains, curved and cross area which were required the braking power under the traffics.

• Korean Journal of Agricultural Science
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• v.42 no.4
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• pp.313-318
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• 2015

In the year 2013, onions cultivation in Jeonnam province suffered by frost-pillar damage. To reveal the aspects of the cause and outbreak, we surveyed those damaged areas. Usually the frost-pillar damage occurred in February. But the outbreak aspect is so unforeseeable. In 2013, the damage was shown as 10.6% in onion fields including paddy fields, but no damage was noticed in 2014. The damage was noticed as 77.8% in paddy fields and 30.1% in upland. And, by the difference of the onion transplanting date, it occurred as 0.7% by the middle of November to the early of November, 22% by the middle of November and 69.0% by the early of December. If one performed the supplementary planting at $3^{rd}$ week of February, the highest survival percent was observed as 53.3%. If the date is early, another frost-pillar damage was occurred. If it's late, the damaged plant was perished with dry. In any case, we found improper transplanting caused the yield decrease. Therefore, we recommend the timely transplanting is the most important way for the prevention of frost-pillar damage in the onion cultivation.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.10 no.2
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• pp.79-90
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• 1990

The National Construction Research Institute of Korea has measured the depth of the frozen ground covering all the areas of South Korea during ten years ranging through 1980. The measurements were made for the frozen ground at random but intended for the most frost-susceptible soils. The soils of the frozen ground were sampled and then classifide into four groups according to the frost design soil classification system suggested by the Corps of Engineers of the United States. The contours of the maximum depth of the frost penetration are drawn on a map with data collected during the ten years. Also isolines of the design frezing index are shown on an another map using the metorological information of 1980-1989 and compared whth those in vestigated in 1980 by Highway Survey Team of the Ministry of Construction, Korea. It is known that the maximum depth of the frost penetration is related to freezing index values. An empirical formula expressing the relation is suggsted, in which the depth is proportional to the one-third power of the air freezing index values.

• Journal of the Korean Geosynthetics Society
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• v.10 no.4
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• pp.93-103
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• 2011

In order to design suitable geo-structures in cold region, it is generally required to consider the mechanical properties of permafrost soils. 'Frost heave' as one of the primary phenomenon is considered to be an important factor together with 'adfreeze bond-strength' and 'creep deformation' for structural design process in permafrost area. Therefore, the fundamental study for frost heave has to be preceded for design of geo-structures in cold region. While various experimental apparatuses have been developed, there still exist a certain level of limitation to evaluate the frost-heave characteristics as design parameters. In this paper, a new type of experimental apparatus is proposed to evaluate the engineering characteristics of frost heave in permafrost soils and a set of verification test results is presented. Based on the verification tests, the proposed apparatus is a suitable to obtain frost characteristics of soils.

• Journal of the Korean Geotechnical Society
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• v.30 no.8
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• pp.39-47
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• 2014

Frost heaving and thawing settlement cause unexpected stress around buried pipelines, which results in deformation and permanent demage. A large scale laboratory test has been performed to observe deformation, stress, and temperature of a buried pipe during atmospheric temperature changes. From the experimental results, the stress concentrated around the buried pipe is inevitable and deformation is caused by the frost heaving. Even though backfill materials are sandy soils which are normally assumed to be non frost susceptible, it is revealed that frost demage can happen due to drainage condition, the level of ground water table, and water content.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.5795-5801
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• 2015

The low temperature distribution of the refrigerated and frozen food has been increased gradually. Refrigeration industry is using R134a refrigerant, which GWP is 1300. R1234yf is an alternative refrigerant of R134a because GWP of R1234yf refrigerant is just 4. Evaporator used in refrigeration truck refrigeration system is operated on low temperature condition. Accordingly, evaporator is formed frost and the formation of frost is rapidly decreased performance of evaporator. In this study, the performance of evaporator using R134a and R1234yf refrigerant was analyzed with operating conditions under frost condition. As a result, the performance of R134a evaporator according to air inlet temperature, relative humidity and evaporating temperature was more sensitive than R1234yf evaporator. Besides, the frost growth of R134a evaporator is steeper than that of R1234yf one.

• Journal of the Korean Geotechnical Society
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• v.25 no.9
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• pp.19-27
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• 2009

In order to investigate anti-freeze process of precast concrete L-type retaining walls in cold regions, test walls were installed in the campus of Kitami Institute of Technology (KIT, Hokkaido, Japan). The wall consists of following three sections, i) back filled with frost susceptible clay soil, ii) using thermal insulation material, and back filled with frost susceptible soil, iii) back filled with frost-unsusceptible soil. The freezing front distribution and ground temperature within the backfill were observed and deflections of the walls were measured over three freeze-thaw seasons. Some understanding of the mechanisms of the build-up of frost heave pressure was gained, and the effectiveness of replacement method was observed. A simulation was performed to predict the shape of the freezing front in the backfill behind L-type walls with various cross sections. These findings were employed to propose a method for determining the appropriate zone to be replaced with frost unsusceptible backfill material in cold regions.

• Journal of the Korean GEO-environmental Society
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• v.25 no.7
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• pp.29-34
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• 2024

Frost heave is one of the significant engineering characteristics of frozen ground and causes severe damages on geo-structures. Although thermo-hydro coupled analyses have been developed to predict frost heave behavior, these analyses involve excessive input parameters and have primarily been validated for frost heave in clayey soils. Frost heave mainly occurs in silty soils, which have relatively higher permeability compared to clayey soils, necessitating careful attention. This study introduces empirical models and verifies their reliability for silty soils. By using the validated model, the correlation of key input parameters is derived, which is expected to enhance the applicability of thermal-mechanical analysis for geo-structures on frozen ground in the future.