• Title/Summary/Keyword: 포스트텐션 콘크리트 포장

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Design Methodology of Gap Slab for Post-Tensioned Prestressed Concrete Pavement (포스트텐션 콘크리트 포장의 Gap Slab 설계 방안)

  • Park, Hee-Beom;Kim, Seong-Min;Shim, Jae-Soo
    • International Journal of Highway Engineering
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    • v.12 no.2
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    • pp.137-146
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    • 2010
  • This study was conducted to develop the design methodology of gap slabs for the post-tensioned concrete pavement (PTCP). The gap slabs were considered as unbonded, half bonded, and bonded types. According to the types of the gap slabs, the curling stresses were investigated first under the environmental loads. The stresses due to the vehicle loads were analyzed considering both the single and tandem axles. The method to calculate the prestressing amount was suggested by comparing the combined stresses due to both loads and the allowable tensile stress of concrete. The prestressing amount for the unbonded type gap slab could be designed by considering only the gap slab; however, for the half bonded and bonded gap slabs, the whole PTCP slab should be analyzed to properly design the prestressing amount.

Characteristics of Ternary Blended Cement Concrete Using Fly Ash and Silica Fume for Post-Tensioned Concrete Pavement Application (포스트텐션 콘크리트 포장 적용을 위한 실리카흄과 플라이 애시를 사용한 삼성분계 콘크리트의 특성)

  • Choi, Pan-Gil;Shim, Do-Sick;Lee, Bong-Hak
    • Journal of the Korean Society of Hazard Mitigation
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    • v.9 no.3
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    • pp.41-47
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    • 2009
  • Post-tensioned concrete pavement(PTCP) was developed to built long-span concrete pavement(120 m span) and to maintain long-term service life(over 40 years) of concrete pavement. In the present study, research for high-durable concrete was conducted to utilize the advantage of PTCP construction method efficiently. First of all, 20% of fly ash(by binder weight) was replaced to control alkali silica reaction. Second, silica fume was applied to improve the water-permeability and early-age strength. Results of tests for mechanical properties, water-permeability resistance, and surface-scaling resistance of ternary blended cement concrete showed that the early-age strength was improved significantly with addition of silica fume. The water-permeability resistance was improved from "Low" to "Very Low"(ASTM C 1202). However, surface-scaling resistance was decreased with an increase of silica fume, therefore, content of silica fume should be kept in less than 5%(by binder weight) to assure field application considering durability. The results of air-void analysis showed that durability factors were improved since spacing factors were estimated as 250$\pm$15 micron in adjusted mixtures.

Field Measurement and Analysis of Post-Tensioned Prestressed Concrete Pavement Behavior under Tensioning (현장실험을 통한 포스트텐션드 프리스트레스트 콘크리트 포장의 긴장 시 거동분석)

  • Park, Hee-Beom;Kim, Seong-Min;Kim, Dong-Ho
    • International Journal of Highway Engineering
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    • v.11 no.1
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    • pp.247-256
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    • 2009
  • This research was conducted to analyze the behavior of PTCP (Post-Tensioned prestressed Concrete Pavement) under tensioning by performing field tests when the experimental PTCP slab was being constructed. The displacements in the slab under the environmental loading and tensioning were measured using temperature measurement sensors and displacement transducers. Tensioning was performed three times and appropriateness of tensioning could be determined by investigating the relationship between temperature and displacement, behavior of transverse crack, and daily change in displacement. The results of this study showed that under the first tensioning at very early age, large displacements were observed only near the joints because of the friction between slab and underlying layer and concrete inelasticity. Under consecutive tensioning, displacements were clearly observed all over the slab, but still affected by the friction. In addition, appropriate tensioning ensured the one-slab behavior of the PTCP slab even though cracks existed.

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Behavior and Design of Terminal Joint Width between Post-Tensioned Concrete Pavement and Jointed Concrete Pavement under Temperature Changes (온도변화에 따른 PTCP와 JCP 접속부 줄눈 폭 변화와 설계 방안)

  • Kim, Dong-Ho;Lee, Bong-Hak;Kim, Seong-Min;Park, Seong-Tae
    • International Journal of Highway Engineering
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    • v.13 no.1
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    • pp.223-228
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    • 2011
  • The initial joint width design of the terminal joint between post-tensioned concrete pavement (PTCP) and jointed concrete pavement (JCP) was studied in this research. The joint width between PTCP and JCP directly affects noise and ride quality. If the initial joint width is very large, noise increases and ride quality decreases. If the initial joint width is very small, on the other hand, under high temperatures, PTCP slabs can blow up, or failures near the joint can occur due to excessive compressive stresses. The terminal joint width behavior between PTCP and JCP near Jumunjin at Donghae expressway under temperature changes was measured in August and November 2010 and the data was analyzed. From this study, the design methodology of the optimal initial terminal joint width was proposed.

Field Application of Post-Tensioned Concrete Pavement for High Speed Weigh-in-motion System (고속축중시스템 설치구간 PTCP 공법의 현장 적용성)

  • Kim, Dong-Ho;Lee, Hyeon-Ho;Kang, Jae-Gyu;Bae, Jong-Oh;Kim, Ki-Heun
    • Proceedings of the Korea Concrete Institute Conference
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    • 2010.05a
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    • pp.449-450
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    • 2010
  • The pavement for high speed weigh-in-motion system have to have durability for a long time without deformation such as rutting so as to sustain precision, accuracy and repeatability. In this paper, PTCP(Post-Tensioned Concrete Pavement) that heavy traffic resistance and durability provide was constructed and field application was evaluated.

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Application of High Durable Concrete in Post-Tensioned Concrete Pavement (포스트텐션 콘크리트 포장에서 고내구성 콘크리트의 적용)

  • Choi, Pan-Gil;Lee, Bong-Hak;Jeong, Beom-Seok;Kim, Dong-Ho
    • Proceedings of the Korea Concrete Institute Conference
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    • 2009.05a
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    • pp.435-436
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    • 2009
  • The objective of this study was to develop the high-durable concrete which is mixed silica fume and fly ash in post-tensioned concrete pavement. Test results show that early-age compressive strength was increased with addition of silica fume. Water-permeability was improved significantly comparing with standard concrete.

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Design Methodology of Longitudinal Post Tensioning for Post-Tensioned Concrete Pavement (포스트 텐션드 콘크리트 포장의 종방향 긴장 설계 방안)

  • Yun, Dong-Ju;Kim, Seong-Min;Bae, Jong-Oh
    • International Journal of Highway Engineering
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    • v.11 no.1
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    • pp.203-215
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    • 2009
  • This study was conducted to develop the design methodology of longitudinal post tensioning for the post-tensioned concrete pavement (PTCP). The longitudinal stress distribution in the PTCP slab was analyzed when post tensioning was applied. Then, the tensile stress distribution in the PTCP slab due to the environmental and vehicle loads needed for the design was investigated. In addition, prestress losses were calculated considering the losses due to the frictional resistance between the slab and underlying layer and due to various reasons related to tensioning. The tensile stresses used for the design were obtained by adding the stresses from the critical conditions under both the environmental and vehicle loads. The prestress losses were obtained by considering actual field conditions. The effective post tensioning amount was determined by considering the design loads including environmental and vehicle loads and various losses, and the effect of the allowable tensile stress on the post tensioning amount was investigated. The initial stage of the design of the longitudinal post tensioning is to obtain the stresses under the design loads and the required prestress determined by subtracting the allowable tensile stress from the design stress. Then, the optimal tendon spacing and the tensioning amount can be obtained by comparing with the effective tensioning amount including various stress losses.

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