• Journal of the Korean GEO-environmental Society
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• v.14 no.6
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• pp.21-29
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• 2013

This paper presents computed frost penetration depths for a number of cross sections of multilayered system including insulation. Results of Modified Berggren method were compared with those of numerical analysis which is based on finite element method with phase change. For the homogeneous single layer medium, Modified Berggren method gives almost the same results as finite element based numerical method. For the multilayered systems with insulation, Modified Berggren method shows, however, inaccurate results compared with FEM results. Therefore numerical solution based on finite element or finite difference should be used in place of Modified Beggren method to estimate the frost penetration depth for the layered medium with insulation.

• 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.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.8 no.2
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• pp.147-154
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• 1988

Korea has the ground which freezes in winter and melts in warmer seasons by turns. Therefore, in designing civil-structures or buildings on such ground, the depth of seasonal frost penetratio must be considered. In this paper, approximate contours of the maximum depth of frost penetration in Korea is presented. It was found that the maximum depth of frost penetration did not have the linear relationship to square root of the freezing index. In order to establish more reliable method to estimate the maximum depth of frost penetration, a new empirical equation is introduced. In the presented equation, the dry unit weight and water content of soil are considered in addition to the freezing index. And the equation is compared with other previous equations used so far.

• 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

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.11a
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• pp.165-166
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• 2020

The climate on the Korean Peninsula has been warmed recently, abnormal weather conditions such as heat waves, cold waves, and tropical nights have been detected frequently. Precisely, the number of days with cold waves in the winter has increased, and rapid changes of temperature in the morning and afternoon have occurred frequently in the 2000s. Due to the previous phenomenons, this research is focused on evaluating the concrete's Chloride Penetration Resistance and Durability, and the difference of the resistance according to the W/C.

• 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.

• Journal of the Korean Data and Information Science Society
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• v.27 no.1
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• pp.67-74
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• 2016

Due to the character of the climate of Korea, the pavement of a road is Influenced by freezing in winter season and thawing in thawing season. In the last few years, several articles have been devoted to the study to minimize the damage of freezing and thawing action. The purpose of this paper is to identify appropriacy of factors that influence road pavement thickness. We conduct the decision tree analysis on the field data of road pavement. The target variable is 'Frost penetration'. This value was calculated from the temperature data. The input variables are 'Region', 'Type of road pavement', 'Anti-frost layer', 'Month' and 'Air temperature'. The region was divided into 9 regions by freezing index $350{\sim}450^{\circ}C{\cdot}day$, $450{\sim}550^{\circ}C{\cdot}day$, $550{\sim}650^{\circ}C{\cdot}day$. The type of road pavement has three-section such as area of cutting, boundary area of cutting and bankin, lower area of banking. As the result, the variables that influence 'Frost penetration' are Month, followed by anti-frost layer, air temperature and region.

• Nuclear Engineering and Technology
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• v.45 no.3
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• pp.393-400
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• 2013

Concrete undergoing early frost damage in cold weather will experience significant loss of not only strength, but also of permeability and durability. Accordingly, concrete codes like ACI-306R prescribe a minimum compressive strength and duration of curing to prevent frost damage at an early age and secure the quality of concrete. Such minimum compressive strength and duration of curing are mostly defined based on the strength development of concrete. However, concrete subjected to frost damage at early age may not show a consistent relationship between its strength and durability. Especially, since durability of concrete is of utmost importance in nuclear power plant structures, this relationship should be imperatively clarified. Therefore, this study verifies the feasibility of the minimum compressive strength specified in the codes like ACI-306R by evaluating the strength development and the durability preventing the frost damage of early age concrete for nuclear power plant. The results indicate that the value of 5 MPa specified by the concrete standards like ACI-306R as the minimum compressive strength to prevent the early frost damage is reasonable in terms of the strength development, but seems to be inappropriate in the viewpoint of the resistance to chloride ion penetration and freeze-thaw. Consequently, it is recommended to propose a minimum compressive strength preventing early frost damage in terms of not only the strength development, but also in terms of the durability to secure the quality of concrete for nuclear power plants in cold climates.

• Corrosion Science and Technology
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• v.6 no.4
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• pp.177-185
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• 2007

The purpose of this study is to evaluate freezing-thawing and surface scaling resistance in order to examine the frost durability of concrete in a chloride-inherent environment. The mixing design for this study is as follows: 3 water binder ratios of 0.37, 0.42, and 0.47; 2-ingredient type concrete (50% OPC concrete and 50% ground granulated blast-furnace slag), and 3-ingredient type concrete (50% OPC concrete, 15% fly ash, and 35% ground granulated blast-furnace slag). As found in this study, the decrease of durability was much more noticeable in combined deterioration through both salt damage and frost damage than in a single deterioration through either ofthese; when using blast-furnace slag in freezing-thawing seawater, the frost durability and surface deterioration resistance was evaluated as higher than when using OPC concrete. BF 50% concrete, especially, rather than BFS35%+FA15%, had a notable effect on resistance to chloride penetration and freezing/expansion. It has been confirmed that surface deterioration can be evaluated through a quantitative analysis of scaling, calculated from concrete's underwater weight and surface-dry weight as affected by the freezing-thawing of seawater.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3D
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• pp.433-439
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• 2011

The frost depth(frost penetration) is used to install anti-frost heave layers in pavement designs. The freezing index is calculated by an annual accumulated value of multiplying the period of time with temperatures below zero, and the corresponding temperature. Therefore, the DAAT(daily average air temperature) calculation method may play an effect on the FI(freezing index). The Weather Observatory used to supply 4 average air temperatures per day, but currently supplies 8 per day. With this study, we divided the southern part(below FI=$350^{\circ}C{\cdot}day$) of the Korean peninsula into 6 areas according to site conditions(low embankment, embankment-cutting slope, and the cutting slope) and established a field measurement system for 15 positions to check the effects on the result of FI according to differing DAAT calculation methods. The air temperatures obtained by the field measurement system was used to calculate and compare the FI. As a result, the freezing index calculated based on the $DAAT_4(T_4)$ is normally greater by 3% than the one on $DAAT_8(T_8)$. In addition, the calibration equation for the freezing index using air temperatures was proposed through the research.