• International Journal of Highway Engineering
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• v.14 no.3
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• pp.25-32
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• 2012

The thickness of anti-freezing layer has been empirically determined using the frost depth obtained from the freezing index and has not been generally considered as a structural layer in pavement design procedure. In fact, the anti-freezing layer makes a role in structural layer and enables to reduce the total thickness of pavement system. The objective of this study is to develop the statistical regression model for evaluating the structural capacity of anti-freezing layer using Falling Weight Deflectormeter(FWD) test data in asphalt pavements. The FWD testing was conducted at the embankment, cutting, and boundary area of various test sections to estimate the structural capacity of anti-freezing layer in different foundation condition. It is observed from this testing that the center deflections of pavement structure with anti-freezing layer are smaller than those without anti-freezing layer ranging from 0.4 to 82.6%. To determine the variables of statistical model, the correlation study has been conducted between various FWD deflection indexes and the anti-freezing layer thickness. It is found that the ${\Delta}BDI$(%)(${\Delta}Basin$ Damage Index(%)) is highly correlated with anti-freezing layer thickness. The ${\Delta}BDI$(%) model were developed for evaluating structural capacity of anti-freezing layer using linear mixed-effect models.

• Geotechnical Engineering
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• v.14 no.1
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• pp.49-58
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• 1998

It was investigated whether the scrap tire can be recycled as a construction material for controlling the frost heave of the ground. Some frost heave tests and a frost penetration depth test in the laboratory were performed on the weathered granite soil mitred with variable amount of scrap tire powder under the atmospheric temperature at -$17^{\circ}$ to find the basic effects of the scrap tire on the control of frost. The frost heave control layer of the crushed stone mixed with scrap tire chips directly below thin subbass in the bituminous pavement was found to be effective for practical use. And the equation for the required thickness of this frost heave control layer with freezing index was suggested.

• International Journal of Highway Engineering
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• v.12 no.2
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• pp.99-106
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• 2010

Until now, the thickness design of anti-freezing layer has been empirically conducted using the frost depth determined from the freezing index. This approach cannot consider the structural properties of anti-freezing layer, which can cause the over-design of pavement structure. This paper presents results of structural evaluation of anti-freezing layer using the Falling Weight Deflectormeter (FWD) deflections. The FWD testing was directly conducted on top of the subbase layer located at the embankment, cutting, and boundary area of each section. It is observed from this testing that the center deflections of pavement structure with anti-freezing layer are smaller than those without anti-freezing layer. The deflection reduction rates are 15~55% in the embankment, 11~64% in the cutting, and 2~38% in the boundary, respectively. It was also found that the use of antifree zing layer enables to reduce the Surface Curvature Index (SCI) values up to 24 percent. Fatigue lives show that pavement structure with antifreezing layer are about two times higher than the those without anti-freezing layer. This fact indicates that the anti-freezing layer should be considered as a structural layer in the asphalt pavement system.

• 한국방재학회:학술대회논문집
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• 2010.02a
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• pp.90.1-90.1
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• 2010

우리나라는 계절적 특성으로 인하여 겨울에서 봄에 이르기까지 도로포장의 동결 융해가 반복되어 도로 파손을 유발 시키고 있다. 동결 융해로 인한 피해를 줄이기 위하여 도로포장 설계시 동상방지층을 별도로 설치를 하고 있으나 실효성 검증 없이 무분별하게 적용되고 있어 국가적으로 예산을 낭비하고 있다. 본 연구에서는 효과적인 동상방지층의 설계를 목적으로 계측된 온도 및 함수비 데이터를 효율적으로 관리하고 모니터링하는 기반을 마련하고자 한다.

• Journal of the Korean GEO-environmental Society
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• v.3 no.1
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• pp.57-66
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• 2002

Generally, the California Bearing Ratio(CBR) for the material of subgrade is estimated without considering the anti-frost layer into the subgrade layer when pavements are designed. A pavement structure is determined according to the CBR. However, recently the design method taking the anti-frost layer into the subgrade layer is getting prevail. It makes the top of the subgrade layer strengthen and the thickness of the road pavement structure decreased. By the way, some confusion may be caused because theoretically the general equation for the mean CBR to combine the material of the subgrade layer and anti-frost layer have not been developed well. In this paper, laboratory and field CBR tests were performed to estimate of the mean CBR for the subgrade layer including the anti-frost layer. From the basis of the test results, modified equation which is calculating the mean CBR of the subgrade layer has been proposed. Finally, economical efficiency was considered by comparing the pavement thickness with the road pavement design using CBR of the subgrade layer alone and the road pavement design using the mean CBR including the anti-frost layer.

• Journal of the Korean Geosynthetics Society
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• v.9 no.3
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• pp.47-56
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• 2010

Korea is known to have seasonal frozen ground during a winter season due to climatic and ground conditions. Temperatures below $0^{\circ}C$ cause pavement failure by frost heaving and thaw settlement. A frost protection layer has been constructed in pavements to avoid damage caused by frost action. Anti-frost design methods in Korea have been adopted, which is established in U.S. and Japan. However the characteristics of soils in Korea are different and there are no reasonable modifications to accommodate these characteristics. Therefore, adequate pavement design procedures including seasonal frost action, as well as construction and maintenance practices are required. In this paper, the frost penetration depths along national roads in Korea are presented based on field measurement over several years (1991~2010). The frost penetration depths are analyzed with respect to the Provinces of Korea and sunny/shaded areas.

• Journal of the Korean Geotechnical Society
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• v.26 no.7
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• pp.71-80
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• 2010

Korea is considered to be a seasonal frozen soil area that thaws in the spring, and freezes in winter. In the current design codes for anti-freezing layer, the thickness of anti-freezing layer is calculated by the depth frozen due to the temperature condition. Therefore, there is a tendency of over-design and applying uniform thickness without the consideration of thermal stability, bearing capacity and frost susceptibility of materials. So, it is essential to study the structural appropriateness of pavement layer and bearing capacity besides the seasonal and mechanical properties of pavement materials to take an appropriate and reasonable design of the road structure. In this paper, the evaluation of frost susceptibility on subgrade, ant-freezing layer, subbase was conducted by means of the mechanical characteristics and model experiment. The temperature, heaving amount, unfrozen water contents and freezing depth of soil samples, the subgrade, anti-freezing layer, subbase soils of road construction site were measured to determine the frost susceptibility.

• International Journal of Highway Engineering
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• v.12 no.2
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• pp.71-79
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• 2010

The influence of fines of the frost susceptibility of subgrade soils were established by laboratory freezing system test simulating closely the thermal conditions in the field. During the winter season, the climate is heavily influenced by the cold and dry continental high pressure. Because of siberian air mass, the temperature of January is $-6{\sim}-7^{\circ}C$ on average. This chilly weather generate the frost heaving by freezing the moisture of soil and damage potential of the road structure. In the freezing soil, the ice lenses increase the freeze portion of soil by absorbing the ground water with capillary action. However, the capillary characteristics differ from the sort of soil on the state of freezing condition. In the current design codes for anti-freezing layer, the thickness of anti freezing layer is calculated by freezing depth against the temperature condition. Therefore, they have a tendency of over-design and uniform thickness without the considerations of thermal stability, bearing capacity and frost susceptibility of materials. So, it is essential for studying the appropriateness and bearing capacity besides the seasonal and mechanical properties of pavement materials to take a appropriate and reasonable design of the road structure. In this Paper, the evaluation of frost susceptibility was conducted by means of the mechanical property test and laboratory freezing system apparatus. The temperature, heaving amount, heaving pressure and unfrozen water contents of soil samples, the subgrade soils of highway construction site, were measured to determine the frost susceptibility.

• Journal of the Korean GEO-environmental Society
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• v.10 no.4
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• pp.15-24
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• 2009

Korea is known to have seasonal frost during winter and the effect of low temperatures and water may cause a weakening of pavements. For that reason, frost protection layers have been constructed in pavements to avoid damage caused by frost action. The practies established in USA and Japan have been adopted as anti-frost design methods in Korea. However, the characteristics of Korean soils are different. Additionally, there is no formulation of a reasonable equation for frost penetration depth and the criterion to identify potentially frost-susceptible soils in present pavement design manuals in Korea. Therefore, adequate pavement design procedures in seasonal frost areas, as well as construction and maintenance practices are required. In this paper, frost penetration depths along national roads in Korea were measured and analyzed over several years. The frost penetration depth was analyzed with respect to the provinces of Korea and sunny/ shaded areas. Additionally, measurement results were compared to the formula of the US Army Corps of Engineers and Ifukube in Japan.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.11a
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• pp.33-34
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• 2011

In this study, using the double bubble sheet to anti-freezing method in winter the soil embanking Mock up as a part of the development process was carried out. As results, two layers of the double bubble sheet effect 12.6℃~13.8℃ temperature difference of out door temperature that proved superior insulation and thermal performance of the double bubble sheet.