• 한국방재학회:학술대회논문집
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• 2007.02a
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• pp.357-360
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• 2007

Water retaining pavement is a pavement to lower the surface temperature by using evaporation of the water that the pavement contains when the pavement is heated by the sun in the daytime. The objective of this study is to develop water retaining materials. In this study we evaluated the practical application of a sepiolite and a charcoal as a water retaining material. We produced dense grade asphalt pavement, porous asphalt pavement, semi-rigid Pavement, semi-rigid pavement included a charcoal and semi-rigid pavement included a sepiolite, and then tested surface temperature characteristics. The test result says that water retaining pavements using a sepiolite and a charcoal lower surface temperature more than $10^{\circ}C$ compared to dense grade asphalt pavement. We confirm the practical application of a sepiolite and a charcoal as a water retaining material according to the test results.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.321-324
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• 2008

Water retaining pavement is a pavement to lower the surface temperature by using evaporation of the water that the pavement contains when the pavement is heated by the sun in the daytime, so, to improve performance, the performance can absorb water. Most of the high-performance material that absorbs water swell $2\sim3$ times as much volume when it contact with water. Water retaining material exists independently of the material in the cement. so it doesn't have the space to expand. Therefore, the performance of absorbing water is decreased. Therefore, this study was to develop a foamed concrete and evaluation of performance characteristics using high absorptiveness resin. The result has been evaluated as excellent compared to other materials.

• International Journal of Highway Engineering
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• v.10 no.2
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• pp.69-79
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• 2008

This study presents the test results on the performance and the moisture retaining ability of semi rigid pavement using the moisture retaining grouting. The two kinds of the grouting materials were used for the Laboratory tests. The method of the tests includes the compression(3 hours and 7 days) and flexural strength(7 days) varying the P lot flow values. The test results show that the variation of the P lot value has no great effects on the strength, however, the different strength was found as the different grouting materials were used. The performance of the semi rigid pavement was evaluated varying the air void ration of the base asphalt pavement. The test results show that the flexural strength of the semi rigid pavement increases with increasing the air void of the base asphalt pavement so that the flexural strength of the semi rigid asphalt pavement can be effected by the air void of the base asphalt pavement. The moisture retaining tests were conducted and compared in the field the comparisons were made with the dense grade asphalt pavement and the semi rigid asphalt pavement with and without spraying the water. The difference of the temperature of the semi rigid pavement with the spraying water has recorded $11^{\circ}C$ when it compared with the dense grade asphalt pavement and $4^{\circ}C$, when it compared with the semi rigid pavement without the spraying the water. It can be seen that decrease the temperature of the pavement by the moisture retaining ability from the semi rigid pavement.

• International Journal of Highway Engineering
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• v.11 no.3
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• pp.97-109
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• 2009

One of the main causes of asphalt rutting is high temperature of the pavement. Nevertheless, there has been few research on lowering the pavement temperature for reducing rutting. This study investigated the performance characteristics of moisture-retaining porous asphalt pavement, which is known to have a temperature reducing effect. The purpose of this study is to quantify the temperature reducing effect of moisture-retaining porous asphalt pavement and its effect of reducing rutting through Accelerated Pavement Testing(APT). Additionally, the possibility of reducing the thickness of the pavement in comparison to general dense grade pavement by analyzing structural layer coefficient of moisture retaining pavement. A total of three test sections consisting of two moisture-retaining porous asphalt pavement sections and one general dense-grade porous asphalt pavement section were constructed for this study. Heating and spraying of water were carried out in a regular cycle. The loading condition was 8.2 ton of wheel load, the tire pressure of $7.03kgf/cm^2$, and the contact area of $610cm^2$. The result of this experiment revealed that the temperature reducing effect of the pavement was about $6.6{\sim}7.9^{\circ}C$(average of $7.4^{\circ}C$) for the middle layer and $7.9{\sim}9.8^{\circ}C$(average of $8.8^{\circ}C$) for surface course, resulting in a rutting reduction of 26% at the pavement surface. Additionally, the structural layer coefficient of moisture retaining pavement measured from a laboratory test was 0.173, about 1.2 times that of general dense grade pavement. The general dense-grade porous asphalt pavement test section exhibited rutting at all layers of surface course, middle layer, and base layer, while the test sections of moisture-retaining porous asphalt pavement manifested rutting mostly at surface course only.

• 한국방재학회:학술대회논문집
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• 2009.02b
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• pp.143.1-143.1
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• 2009

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.3D
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• pp.271-278
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• 2010

Semi rigid pavement is a pavement type using advantages of both flexibility of asphalt pavement and rigidity of concrete pavement by infiltrating cement paste into voids of open graded asphalt mixtures. The semi rigid pavement has better smoothness and smaller driving vibration or noise comparing to the concrete pavement, and has smaller permanent deformation and has temperature falling effect comparing to the asphalt pavement. The temperature falling effect were investigated at a semi rigid overlay pavement test section, and the temperature falling and water retaining effects were verified by measuring the temperature and weight of specimens at a housetop. Horizontal and vertical stresses and strains were compared by structural analysis of the semi rigid pavement and asphalt pavement using the Abaquser o, a commercial 3D finite element analysis program. The results were verified by Bisar 3.0, a multi-layered elastic analysis program. Performance of the semi rigid pavement and asphalt pavement were compared by predicting fatigue cracking based on the structural analysis results.

• International Journal of Highway Engineering
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• v.16 no.3
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• pp.51-57
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• 2014

PURPOSES : This study is to suggest tunnel length to spray curing compound, based on the field tests. METHODS : At first field test, length from the entrance of tunnel to wet wall was checked by visual survey. The second and third test, various sensors were installed in concrete or in tunnel, such as RH sensor, temperature sensor, portable weather station and etc.. And also, test for bleeding and retaining water of concrete were conducted to evaluate environmental effect on concrete pavement. RESULTS : The result of the field experiment for tunnel length to spray curing compound indicates that length changes depending on tunnel length, season, and location. Environmental condition of a short tunnel was not much different between location near entrance and at center of tunnel. However, in case of a medium and long tunnel, effect of outside environmental condition decreased, when location moved into tunnel center of it. CONCLUSIONS : From the testing results, it can be proposed that optimum tunnel length to spray curing compound is 60m for a medium and long tunnel, and whole length for a short tunnel.