• Title/Summary/Keyword: transverse tensioning

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Analysis of Post-tensioned Bridge by Specially Orthotropic Laminate Theory (I) - Reinforced Concrete Slab Bridge (특별직교이방성 이론에 의한 포스트 텐션된 교량의 해석(I) - 철근 콘크리트 슬래브교 -)

  • 김덕현;원치문;이정호
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2001.05a
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    • pp.135-140
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    • 2001
  • A post-tensioned reinforced concrete slab bridge is analyzed by specially orthotropic laminate theory. Symmetrically reinforced slab with tension and compression steel is considered for convenience of analysis. Each longitudinal and transverse steel layer is regarded as a lamina, and material constants of each lamina is calculated by the use of the rule of mixture. This bridge is under uniformly distributed vertical loads, and axial loads and end moments due to post-tensioning. In this paper, finite difference method is used for numerical analysis of this bridge. Theory and analysis method of specially orthotropic laminate plates used in this paper can be used for design of new bridges, and maintenance and repair of old bridges.

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Design Guide of Post-Tensioned Prestressed Concrete Pavement (포스트텐션 콘크리트 포장 공법 설계지침 개발)

  • Park, Hee-Beom;Kim, Seong-Min;Bae, Jong-Oh
    • Proceedings of the Korea Concrete Institute Conference
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    • 2010.05a
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    • pp.17-18
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    • 2010
  • This study was conducted to develop the design guide of PTCP (Post Tensioned Concrete Pavement). The behavior of PTCP was investigated by performing structural analyses and field experiments. Based on the results, the PTCP design guide was developed by determining the size of concrete slab, design environmental and vehicle loads, and amount and method of longitudinal and transverse tensioning.

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Ultimate Strength of Anchorage Zone according to Geometric Parameters of Post-Tensioning Anchorage using a Finite Element Method (유한요소해석을 통한 포스트텐션 정착구 형상 변수의 정착부 극한강도 영향 분석)

  • Kwon, Yangsu;Kim, Jin-Kook;Kwak, Hyo-Gyoung
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.28 no.3
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    • pp.317-324
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    • 2015
  • The design of anchorage zone in a post-tensioned member has been started from the evaluation of the ultimate resisting capacity as well as the maximum bursting stress developed, and a lot of design codes including AASHTO and PTI describe their design equations to determine the bearing strength of concrete at the anchorage zone. However, these equations usually give conservative results because their derivation is based on the simple anchorage with a wide bearing plate in the surface without any additional consideration for the load transfer mechanism through transverse ribs on the anchorage. To assess the influence of geometric parameters related to the transverse ribs on the resisting capacity of anchorage block, experiments and analysis are conducted. After verifying the validity of numerical model conducted through correlation studies between experimental and analytical results, parametric studies with changes in the transverse ribs are followed and design recommendations for the anchorage block are suggested from the numerical results obtained.

Influence of steel fiber and reinforcing details on the ultimate bearing strength of the post-tensioning anchorage zone

  • Kim, Jin-Kook;Yang, Jun-Mo;Kwon, Yangsu
    • Structural Engineering and Mechanics
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    • v.59 no.5
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    • pp.867-883
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    • 2016
  • In this paper, the effects of steel-fiber and rebar reinforcements on the ultimate bearing strength of the local anchorage zone were investigated based on experiments and comparisons between test results and design-equation predictions (AASHTO 2012, NCHRP 1994). Eighteen specimens were fabricated using the same anchorage device, which is one of the conventional anchorage devices, and two transverse ribs were used to secure an additional bearing area for a compact anchorage-zone design. Eight of the specimens were reinforced with only steel fiber and are of two concrete strengths, while six were reinforced with only rebars for two concrete strengths. The other four specimens were reinforced with both rebars and steel fiber for one concrete strength. The test and the comparisons between the design-equation predictions and the test results showed that the ultimate bearing strength and the section efficiency are highly affected by the reinforcement details and the concrete strength; moreover, the NCHRP equation can be conservatively applied to various local anchorage zones for the prediction of the ultimate bearing strength, whereby conditions such as the consideration of the rib area and the calibration factor are changed.

Analysis on Shapes of Shear Pocket for the Full-Depth Precast Slab (프리캐스트 바닥판의 전단포켓 형상에 관한 해석 연구)

  • Han, Sang Yun;Lee, Man Seop;Lee, Seung Rok;Kang, Young Jong
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.5A
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    • pp.817-822
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    • 2006
  • Post-tensioning the full-depth precast slab longitudinally is to eliminate the tensile stresses in the transverse joints and to prevent any leakage through the joints. When the prestressing is applied to full-depth precast slab which does not composite steel girder, stress concentration occurs at the corners of shear pocket, and compressive stress is not uniformly distributed in the section of precast slab. In this paper, full-depth precast slabs using four different shapes of shear pockets are analyzed by commercial finite element program. Round type of shear pockets is superior to reduction in stress concentration.