• Title/Summary/Keyword: precast and new concrete

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Development of Construction Method and Design Guide for Newly Constructed Precast Concrete Pavements (신설 프리캐스트 콘크리트 포장 시공방법 및 설계지침 개발)

  • Kim, Seong-Min;Park, Hee-Beom;Yang, Sung-Chul;Han, Seung-Hwan
    • International Journal of Highway Engineering
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    • v.10 no.2
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    • pp.193-203
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    • 2008
  • This study was conducted to investigate the feasibility of the expedite construction of new pavement systems using precast concrete slabs and to develop the design and construction guide based on the results of the experimental construction. Half scale concrete slabs were designed and fabricated and the optimal reinforcement design, linkages between the slabs in the longitudinal and transverse directions, and the grouting methods were investigated. The experimental construction was performed fast and easily by assembling two slabs in the longitudinal direction and the other two in the transverse direction. The slabs were leveled and the pockets and the space between the slab bottom and the underlying layer were grouted. From the experimental construction, details about the design and construction of the precast pavements were acquired. Finally, the design and construction guide for the newly constructed precast concrete pavement systems was developed.

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Analysis on the Flexural Behavior of Existing Reinforced Concrete Frame Structures Infilled with L-Type Precast Wall Panel (L형 프리캐스트 콘크리트 벽패널로 채운 기존 철근 콘크리트 골조 구조물의 휨 거동 분석)

  • Yu, Sung-Yong;Ju, Ho-Seong;Son, Guk-Won
    • Journal of the Korean Society for Advanced Composite Structures
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    • v.6 no.2
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    • pp.52-62
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    • 2015
  • This study aims at developing a new seismic resistant method by using precast concrete wall panels for existing low-rise, reinforced concrete beam-column buildings such as school buildings. Three quasi-static hysteresis loading tests were performed on one unreinforced beam-column specimen and two reinforced specimens with U-type precast wall panels. Top shear connection of the PC panel was required to show the composite strength of RC column and PC wall panel. However, the strength of the connection did not influence directly on the ultimate loading capacities of the specimens in the positive loading because the loaded RC column push the side of PC wall panel and it moved horizontally before the shear connector receive the concentrated shear force in the positive loading process. Under the positive loading sequence(push loading), the reinforced concrete column and PC panel showed flexural strength which is larger than 97% of the composite section because of the rigid binding at the top of precast panel. Similar load-deformation relationship and ultimated horizontal load capacities were shown in the test of PR1-LA and PR1-LP specimens because they have same section dimension and detail at the flexural critical section. An average of 4.7 times increase in the positive maximum loading(average 967kN) and 2.7 times increase in the negative maximum loading(average 592.5kN) had resulted from the test of seismic resistant specimens with anchored and welded steel plate connections than that of unreinforced beam-column specimen. The maximum drift ratios were also shown between 1.0% and 1.4%.

Strength Propreties of Binary and Ternary Blended of Ultra Flowing Self-Compacting Concrete (2성분계 및 3성분계 초유동 자기충전 콘크리트의 강도 특성)

  • Choi, Yun-Wang;Kim, Kyung-Hwan;Ha, Sang-Woo;Moon, Dae-Joung;Kang, Hyun-Jin
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.11a
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    • pp.489-492
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    • 2006
  • Needs for the new technologies and cutting-edge Ultra Flowing Self-Compacting Concrete are emerging as the concrete structures are becoming bigger and more specialized recently. In North America and Europe, SCC, which has high resistance against flow ability and segregation, is being used as concrete material in applications such as precast and prestressed bridges, where reinforcing bars are overcrowdedly placed. In Korea, SCC has been utilized limitedly in building structures but its utilization should be expanded to engineering structures such as bridges. In this study, for the application in precast and prestressed bridges with overlycrowded reinforcing bars, USCC was mixed with admixtures to give a binary system and a ternary system according to the 1st grade rules by JSCE (Japan Society of Civil Engineers). Compressive strength and splitting tensile strength of the resulting USCCs were tested. Elastic modulus were compared with the values suggested in CEB-FIP code and ACI 318-05.

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Study on the Performance of New Shear Resistance Connecting Structure of Precast Member (프리캐스트 부재의 새로운 전단저항 연결체의 성능에 관한 연구)

  • Kim, Tae-Hoon;Jin, Byeong-Moo;Kim, Young-Jin;Kim, Seong-Woon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.1A
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    • pp.147-154
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    • 2008
  • The purpose of this study is to critically evaluate the structural performance of an innovative new shear resistance connecting structure of precast member. Joints such as shear resistance connecting structure require special attention when designing and constructing precast segmental structures. An experimental and analytical study was conducted to quantify performance measures and examine one aspect of detailing for developed shear resistance connecting structure. A computer program, named RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology), for the analysis of reinforced concrete structures was used. A joint element is used to predict the inelastic behavior of the joints between segmental members. Future work by the authors will do a model test of precast segmental prestressed concrete bridge columns with this shear resistance connecting structure, and examined both the structural behavior and seismic performance.

Evaluation of Drainage Capacity of Precast Concrete-panel Retaining Wall Attached to In-situ Ground Using Numerical Analysis (수치해석을 이용한 원지반 부착식 판넬옹벽의 투수성 평가)

  • Kwon, Youg Kyu;Lee, Jae Won;Hwang, Young-cheol;Ban, Hoki;Lee, Minjae
    • Journal of the Korean Geotechnical Society
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    • v.37 no.3
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    • pp.43-50
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    • 2021
  • On the construction of new roads, the cut slope is inevitable and thus has been widely applied in the mountainous area. Particularly, the retaining wall with the precast concrete panel is often selected for its higher stability and mostly constructed in bottom-up method. However, the bottom-up method results in steeper slope as 1:0.05 before constructiong retaining wall and thus causes poor compaction at backfill which may induce instability during or after the construction. To overcome this problem, precast concrete panel retaining wall was attached in-situ ground (so called top-down). This paper presents the evaluation of drainage capacity of top-down method which has impermeable layer between panel and mortar being used to increase the ability of attachment of the precast concrete panel.

Evaluation of Field Application of Precast Concrete-panel Retaining Wall attached to In-Situ Ground Using Field Test and Numerical Analysis (현장시험 및 수치해석 분석을 통한 원지반 부착식 판넬옹벽의 현장 적용성 평가)

  • Kwon, Yong Kyu;Min, Kyoung-nam;Hwang, Young-cheol;Ban, Hoki;Lee, Minjae
    • Journal of the Korean Geotechnical Society
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    • v.36 no.12
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    • pp.99-106
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    • 2020
  • Man-made slope is inevitable to make a new road, which may result in environmental problems as well as collapse of slope. To prevent these problems, various methods such as geogrid reinforced retaining wall, precast concrete-panel retaining wall, and so on, have been introduced and developed. Among these methods, this paper presents the evaluation of field application of precast concrete-panel retaining wall attached to in-situ ground (so called top-down) compared to the conventional construction method of precast concrete-panel retaining wall (so called bottom-up) through the field test and numerical analysis. As a result, the safety factor of both methods in final stage is similar, however, top-down method guarantees the slope stability during the construction compared to bottom-up method.

Cracking of a prefabricated steel truss-concrete composite beam with pre-embedded shear studs under hogging moment

  • Gao, Yanmei;Zhou, Zhixiang;Liu, Dong;Wang, Yinhui
    • Steel and Composite Structures
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    • v.21 no.5
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    • pp.981-997
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    • 2016
  • To avoid the cracks of cast-in-place concrete in shear pockets and seams in the traditional composite beam with precast decks, this paper proposed a new type of prefabricated steel truss-concrete composite beam (ab. PSTC beam) with pre-embedded shear studs (ab. PSS connector). To study the initial cracking load of concrete deck, the development and distribution laws of the cracks, 3 PSTC beams were tested under hogging moment. And the crack behavior of the deck was compared with traditional precast composite beam, which was assembled by shear pockets and cast-in-place joints. Results show that: (i) the initial crack appears on the deck, thus avoid the appearance of the cracks in the traditional shear pockets; (ii) the crack of the seam appears later than that of the deck, which verifies the reliability of epoxy cement mortar seam, thus solves the complex structure and easily crack behavior of the traditional cast-in-place joints; (iii) the development and the distribution laws of the cracks in PSTC beam are different from the conventional composite beam. Therefore, in the deduction of crack calculation theory, all the above factors should be considered.

Evaluation of Fire Performance for High Strength Concrete Mock-up Column with Fiber by Unloaded Fire Test (비재하 내화시험에 의한 섬유혼입 고강도 콘크리트 Mock-up 기둥의 내화성능 평가)

  • Song, Young-Chan;Kim, Yong-Ro;Kim, Ook-Jong;Lee, Do-Bum
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2009.11a
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    • pp.97-100
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    • 2009
  • Fire resistance properties and mechanical properties of high strength concrete mock-up column using organic fiber by KS F 2257 Methods of fire resistance test for elements of building construction and compression test was investigated for application of precast concrete column method of high rise building in this study. As a test result, it was appeared that ECC permanent form is available as fire resistance method of high strength concrete and new precast concrete construction method for facilitating construction of high rise building.

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An Experiment and Analysis of Precast Concrete Baseplate on Bimodal Tram Dedicated Bridge (바이모달 트램(Bimodal Tram) 전용교량에 적용된 프리캐스트 콘크리트 바닥판의 거동특성 분석에 관한 실험 및 해석적 연구)

  • Cheon, Ju Hyoun;Joo, Young Jong;Kim, Ryang Gyun;Yoon, Hee Taek
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.15 no.2
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    • pp.116-124
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    • 2011
  • To purpose of this study is to develop the new type of precast concrete baseplate which is only for bimodal tram. The experiments with real size specimens, which are hollowed precast baseplate, prove the efficacy of new designed baseplate by comparing with the result of RCAHEST. Through tests progressed according to different loading locations, the specimens show the stability by the safety factor of 8~9. Also the results of RCAHEST that is the nonlinear finite element method program, appropriately estimate the occuring crack on concrete, yielding reinforcement and ultimate behavior at failure.

An Experimental Study on the Fire Resistance and Mechanical Properties of ECC Permanent Form (ECC 영구거푸집의 내화성능 및 역학적 특성에 관한 실험적 연구)

  • Kim, Yong-Ro;Song, Young-Chan;Oh, Jae-Keun;Kim, Jae-Hwan;Kim, Ook-Jong;Lee, Do-Bum
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2009.05c
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    • pp.75-78
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    • 2009
  • It was investigated fire resistance properties and mechanical properties of high strength concrete column using ECC(Engineered Cementitious Composites) permanent form by KS F 2257 Methods of fire resistance test for elements of building construction and compression test for application of precast concrete column method of high rise building in this study. As a test result, it was appeared that ECC permanent form is available as fire resistance method of high strength concrete and new precast concrete construction method for facilitating construction of high rise building.

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