• Title/Summary/Keyword: 포장궤도

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Improvement of Dry-blasting Efficiency for Ballast used as Aggregate of Paved Track (포장궤도 골재용 도상자갈의 건식 블라스팅 효율 향상 연구)

  • Lee, Il-Wha
    • Journal of the Korean Society for Railway
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    • v.13 no.1
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    • pp.78-83
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    • 2010
  • On the paved track, the ballast is used as aggregate for the filling layer using the pre-packed concrete technique. The most important condition of aggregate is adhesive strength with mortar. To satisfy this condition, surface of aggregate should be cleaned by water or others. In a paved-track method to be introduced domestically, an environment-friendly dry-washing technology which will replace the water-washing method has been developed. A dry-washing method was designed to blast the crushed weight material with a diameter of 0.3~0.5mm at high pressure to peel the surface of the aggregate. The study was intended to enhance the washing efficiency of dry-blasting technology and to that end, the tests including blasting material, content of fine aggregate depending on time elapsed, content of chloride, LA abrasion rate and compressive strength were conducted to recommend the efficient washing material and the process.

Deformation Characteristics of Construction Joint of Paved Track on Earthwork Section using the Accelerated Track Test (궤도가속실험을 통한 포장궤도 토공구간 시공이음매부의 변형특성 연구)

  • Lee, Il-Wha;Jang, Seung-Yup;Kang, Yoon-Suk;Um, Ju-Hwan;Kim, Eun
    • Journal of the Korean Society for Railway
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    • v.13 no.5
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    • pp.521-527
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    • 2010
  • The Paved Track is applied to reduce maintenance cost of conventional line. The Paved Track could be used in all types of lines including earthwork, bridge, tunnel and turnout sections. In case of earthwork section, the construction joint is the most critical factor to track durability. The construction joint does not affect to the track structure directly, but the gap due to discontinuity of slabs may affect to the long-term serviceability. To evaluate this problem, the accelerated track test has been performed on the construction joint and the middle part to of the real scale Paved Track. The purpose of this test is that evaluate the vulnerability of construction joint section comparing the trends of settlement and earth pressure under repeated loads of construction joint with those of the middle slab part.

Aggregate Criterion for Paved Track Considering Recycling of Railway Ballast (도상자갈 재활용을 고려한 포장궤도용 골재 기준)

  • Lee, Il-Wha
    • Journal of the Korean Society for Railway
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    • v.12 no.4
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    • pp.481-487
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    • 2009
  • On the paved track, the railway ballast is used as aggregate for the filling layer using the pre-packed concrete method. The condition of ballast as the paved track aggregate ensure that the compressive strength, particle distribution size for the pouring and surface clearance to increase the adhesive strength with mortar. It is profitable to recycle the existing railway ballast as a economical supply. In order to increase recycling characteristic, it is necessary to apply the similar criterion which does not exceed the conventional railway ballast criterion. Consequently, this paper was to investigate physical characteristics of existing ballast, particle size distribution, compressive and flexural strength, bearing capacity and filling capacity to prepare the aggregate's recycling. As a result, optimized aggregate criterion is suggested.

An Experimental Study for Determination of the Paved Track Structure (포장궤도 구조 결정을 위한 실험적 연구)

  • Shim Nak-Hoon;Lee Il-Hwa;Park Young-Suk
    • Proceedings of the KSR Conference
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    • pp.1026-1032
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    • 2004
  • The objective of this study is to confirm the field application of coarse aggregates technology mixtured with high strength mortar under the rail. In the present study, the field tests are performed to find the field state and aggregate gradations and the laboratory tests are performed to find the compressive strength of the pre packed concrete cylinder specimens and the core specimens obtained at the field.

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Study on the Full-Scale Cyclic Loading Characteristics for Cement Mortar Pouring type Paved Track (시멘트모르터 충진형 포장궤도의 실물 반복재하특성에 관한 연구)

  • Lee Il-Wha;Jang Seung-Yup;Kim Eun
    • Journal of the Korean Society for Railway
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    • v.9 no.3
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    • pp.305-312
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    • 2006
  • Gravel ballasted tracks are used as a basic structure for the domestic railway tracks. However, such kind of tracks has few disadvantages with service life of the structure, such as rapid deterioration of the tracks. Due to this reason, there is a need to develop low maintenance track to improve the service life of the conventional line tracks. CMP paved tacks are one of the kind of concrete tracks those were manufactured by using the prepacked concrete techniques. The purpose to develop paved tracks is to reduce the maintenance cost. The most important controlling factors to design the paved tracks are surrounding environmental condition and repeated train loading. In this study, in order to investigate the deformation characteristics such as displacement, earth pressure, strain ratio, and crack along the repeated loading cycle, cyclic loading test through real scale model was carried out.

A Study on Transferred Load Reduction on Paved Track Roadbed with Low Elastic Base Plate Pad (저탄성 베이스플레이트 패드 적용에 따른 포장궤도 노반에서의 전달하중 저감에 관한 연구)

  • Lee, Il-Wha;Kang, Yun-Suk;Lee, Hee-Up
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.3D
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    • pp.399-405
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    • 2008
  • Development of the paved track is required as a low-maintenance of conventional line. The paved tracks are one of the types of the ballast reinforced tracks those are manufactured by adopting the prepacked concrete technique. The main elements of this tracks are large sleeper, low elastic pad, fastener, cement mortar, geotextile and recycled ballast. Low elastic pad is the most effective element of such tracks on the basis of stress-displacement characteristics, dynamic response and fatigue characteristics. The stiffness of the pad determine the stiffness of the track. Consequently, it is more important in case of concrete track structure such as paved track because application of low elastic pad seriously effect the durability and stability of the track. The main objective of this study is to confirm the reduction of train load, which transfer to roadbed through various pad effects. To achieve this task static, numerical analysis and real scale repeated loading test was performed while load reduction effect of low elastic pad was analyzed by using displacement, stress and strain ratio characteristics of the paved track.

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Transferred Load Reduction effect on Paved Track Roadbed with Low Elastic Base Plate Pad (포장궤도에서의 저탄성패드 적용에 따른 전달하중 저감 효과)

  • Lee, Il-Wha;Kim, Eun;Kim, Chang-Hwan
    • Proceedings of the KSR Conference
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    • pp.1230-1235
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    • 2011
  • The track stiffness is determined by the pad stiffness. Low elastic pad is the most effective track component on the basis of stress-displacement characteristics, dynamic response and fatigue characteristics. It is more important in case of concrete track. The main objective of this paper is to confirm the reduction effect of train load, which transfer to roadbed through track. To achieve this object, numerical analysis and real scale repeated loading test was performed. The load reduction effect of low elastic pad was analyzed by using displacement, stress and strain ratio of the paved track at each point.

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The Dry Cleaning Machine to Recycling the used Ballast as a Aggregate of the Paved Track (포장궤도 골재로서의 도상자갈 재활용을 위한 건식세척장치)

  • Lee, Il-Wha;Lim, Jong-Il;Lee, Soon-Gu
    • Proceedings of the KSR Conference
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    • pp.1525-1529
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    • 2009
  • Washed ballast is used on paved track to earn the high quality track performance. But, the water washing system caused the several environment problems such as the noise, dust and water pollution. Even if the washing is performed, it is difficult to earn the high quality because of the low efficiency of the water washing system. So, we developed the dry cleaning type machine to solve these problems. This machine excludes using the water completely. Especially, it is possible to organize on the conventional ballast cleaning train set.

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