• Title/Summary/Keyword: LTPP

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Analysis of the Performance of Crack and Seat Method using the LTPP Data (LTPP Data를 이용한 균열 및 안치(Crack and Seat) 공법 효과 분석)

  • Lee, Seung Woo;Hwang, Eun Sik
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.4D
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    • pp.609-615
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    • 2006
  • Crack and seat method has been used in United States to prevent reflection cracks of overlay that may be caused by excessive movement at discontinuity of old concrete pavement. This method provide optium space of discontinuity by generating additional discontinuity in old concrete pavement. In this study the effect of various factors on the performance such as IRI and distress at after applying crack and seat method were investigated by using LTPP data.

Verification of Freezing Index and Frost Penetration Depth with Temperature Data of Korea LTPP (국내 LTPP 온도 자료를 이용한 동결지수와 동결깊이 검증 연구)

  • Kim, Boo-Il;Jeon, Sung-Il;Lee, Moon-Sup;Lim, Kwang-Su
    • International Journal of Highway Engineering
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    • v.11 no.4
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    • pp.143-152
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    • 2009
  • The purpose of this study is to evaluate the freezing index and frost penetration depth. The freezing index and frost penetration depth were analyzed using air temperature and temperature profile of pavement system in Korea LTPP-SPS(Long Term Pavement Performance-Specific Pavement Study) site. The predicted frost penetration depth were then compared with the measured one from the LTPP sites. And the trend of annual freezing index was analyzed using the temperature data of meteorological stations located in the vicinity of Korea LTPP-SPS site. The result showed that the freezing index was rapidly decreased since 1987, and it was known that the use of freezing index determined from the past 30 years temperature data could cause the over estimates in the pavement thickness design. The temperature profile measured at 3 sections of LTPP-SPS sites showed that the temperature of subbase layer was above $0^{\circ}C$, even though anti-frost layers were found in these sections. Comparing the measured and calculated frost depth, the frost depth calculated from the subgrade frost penetration permissible method showed a similar trend with the measured frost depth.

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An Estimation Procedure for Concrete Modulus by Using Concrete Strength Relationships in the LTPP Test Sections (콘크리트 물성 정량화식을 이용한 LTPP 구간의 탄성계수 추정방법)

  • Yang, Sung-Chul;Cho, Yoon-Ho
    • Journal of the Korean Society of Hazard Mitigation
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    • v.10 no.2
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    • pp.39-46
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    • 2010
  • Concrete strength relationship between various strength properties was presented through experimental data from concretes made from different sources of coarse aggregates and fine aggregates, and different amount of cement contents. In the strength relationship were included compression-flexure, compression-split tension, compression-modulus and flexure-split tension. A total of 61~81 data sets were analyzed while each data set is composed of 3 to 4 experimental test data. Using the proposed strength relations, a procedure to reliably estimate modulus values from the LTPP field test section was suggested. Core specimens were taken from 10 LTPP sections on the expressway as well as 4 sections on the national road. Then compressive strengths and modulus were determined in the lab. Finally concrete modulus was averaged with the estimated values by using the derived relationship and experimental values.

A Study on the Factors Affecting on the Life of Bonded Concrete Overlay Pavement using the LTPP Data of U.S.A (미국 LTPP Data를 활용한 접착식 콘크리트 덧씌우기 포장 수명에 영향을 미치는 인자에 관한 연구)

  • Lee, Seung Woo;Son, Hyeon Jang
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.4D
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    • pp.555-564
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    • 2011
  • More than sixty percentages of the highway constructed by concrete pavements in South Korea and over half of the concrete pavements were twenty years or older. The most of South Korea road is hard to provide a bypass in conditions of network of roads. Asphalt concrete overlay has been used for the overlay of aged concrete pavement. However, the cost of maintenance and rehabilitation in an asphalt overlay is expensive by early damage. Therefore, bonded concrete overlay was recently attempted in South Korea as an alterative method of rehabilitation for aged concrete pavement. Hence, it needed to investigate the factors to find performance of the bonded concrete overlay life. However, there is no performance data of the concrete overlay in South Korea. This study was to make a database of an affecting of the pavement life and draws statistical analysis of the performance data on the LTPP (Long Term Pavement Performance) database of U.S.A.

Development of Calibration Model and Analysis of Soil Water Content using Time-Domain Refelctometry Probe in LTPP Sections (LTPP 구간에서 TDR 방식 함수량계를 이용한 현장함수비 보정모델 개발과 함수비 분석 연구)

  • Kim, Boo-Il;Jeon, Sung-Il
    • International Journal of Highway Engineering
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    • v.7 no.4 s.26
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    • pp.103-112
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    • 2005
  • Water content of sub-layer in pavement systems has a large effect on pavement performance. Many researchers lately make use of time-domain reflectometry(TDR) probes to measure the soil water content of sub-layer from field monitoring. The laboratory calibration test of TDR probe should be performed with soil field, because TDR probe can cause an error by type, gradation, density, and temperature of soil. This study performed the laboratory calibration test of TDR probe(CS616) with subgrade and subbase material in long term pavement performance(LTPP) sections. And the calibration equations of TDR probe(CS616) were then proposed. It was confirmed from the study that the data of TDR probe monitored in field could be used to estimate the freezing, unfrozen water content, and matric suction of soil.

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