• Title/Summary/Keyword: precast concrete structures

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Analysis on Tower Crane Selection in Precast Concretes Structures and its Connection with Precast Rate

  • Guo, Jingjing;Fu, Yan;Wang, Kang;Peng, Zhenyu
    • International conference on construction engineering and project management
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    • 2017.10a
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    • pp.192-200
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    • 2017
  • With the acceleration of construction industrialization, the buildings that China has adopted the construction of industrialization technology are increasing day by day, and Precast Concrete (PC) Structure technology is one of the main technologies of construction industrialization. Compared with the traditional cast-in-place concrete structure, PC structure is more conducive to shorten the construction period, reduce the number of construction workers and the site construction waste. Nevertheless, PC structure improves the requirements of hoisting machinery in the construction site, and the lay-out and selection of hoisting machinery become an important factor influencing the construction cost. The paper regards the typical tower crane in China as the research object, and establishes the time optimization model for the lifting scheme. The influence of the different precast rate on the selection of the tower crane is analyzed. This paper obtains the time variation of the tower crane under different precast rate, provides a theoretical basis for the design of precast concrete structures under the influence of assembly construction, and lays the foundation for the selection of tower crane under the precast rate.

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Effective Stiffness of Horizontal Joints in Precast Concrete Large Panel Structures (프리캐스트 콘크리트 대형판구조물의 수평접합부 유효강성)

  • 장극관;이한선;신영식;류진호
    • Proceedings of the Korea Concrete Institute Conference
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    • 1993.10a
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    • pp.278-283
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    • 1993
  • Though stiffnesses of joints in precast concrete (P.C) large structures are known to be generally less than those in monolithic reinforced concrete wall structures, designers have very little information on the quantitative values with regards to these stiffnesses. The aim of this paper is to provide this quantitative information, in particular, on the compressive stiffness of horizontal joints, based on the analytical results derived from several experiments. Also, it is shown that the approach from the contact problem to determine this stiffness gives a value very similar to those obtained above.

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Dynamic Analysis of Precast Concrete Large Panel Structures with Horizontal Joints (수평 접합부를 고려한 프리캐스트 대형판 구조물의 동적 해석에 관한 연구)

  • 정일영;송진규;강해관
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1996.10a
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    • pp.249-257
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    • 1996
  • Dynamic Analysis of Precast Concrete Large Panel Structures with Horizontal Joints The damage in precast large panel structures subjected to destructive earthquakes is generally localized in the joints. Particularly, the horizontal joints influence on the stability and integrity of the overall structure. In this research a dynamic analysis was carried out by the macro model that idealized the horizontal joints as inelastic-nonlinear spring systems. It is capable of simulating the behavior of precast concrete structures using the mathematical model. As a result of the dynamic parametric study for the case of 0.12g peak base accelerations, it is found that all joints behave elastically for sliding and opening and that all forces are well distributed without excessive local concentration on my horizontal joints.

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In-situ Production Analysis of Composite Precast Concrete Members of Green Frame

  • Lim, Chae-Yeon;Joo, Jin-Kyu;Lee, Goon-Jae;Kim, Sun-Kuk
    • Journal of the Korea Institute of Building Construction
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    • v.11 no.5
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    • pp.501-514
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    • 2011
  • Recently, there have been many cases in which the difficulty of repair and replacement of principal elements in the bearing wall structure for apartment buildings, which is a major part of apartment buildings in Korea, has led to the reconstruction of buildings rather than their remodeling. To address this problem, the Korea government now allows a floor area ratio of up to 20 %, and has relaxed the building height limits to encourage the use of a rahmen structure instead of a bearing wall structure. However, since reinforced concrete rahmen structures have many problems, including higher floor height and greater construction cost, a great deal of research into rahmen composite precast concrete structures have been conducted. Green Frame, one of the developed prototypes, is expected to provide economic benefits through in-situ production for precast concrete column and beam. For in-situ production of composite precast concrete members, a detailed plan for production, curing, and installation is needed. However, it needs to be confirmed that the space is sufficient to produce the precast concrete members on-site before planning those activities. Therefore, this study proposes in-situ production analysis of composite precast concrete members of Green Frame with the evaluation of structural safety and available area on the parking structure. The result of this study shows that the in-situ production of precast concrete members is possible through a case study.

An Experimental Study on Compressive Loading Capacity of Precast Concrete Truss System (프리캐스트 콘크리트 트러스 시스템의 압축 내하력 실험 연구)

  • Han, Man-Yop;Jeon, Se-Jin
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.3
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    • pp.889-900
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    • 2013
  • In a large scale of excavation for the foundation of large-sized structures and underground structures, a considerable amount of earth pressure can occur. Steel beams that have been used to form a temporary structure to support earth pressure may be less economical and less efficient in resisting the high earth pressure. To cope with this problem, PCT(Precast Concrete Truss) system has been devised and investigated both experimentally and analytically. A proper connection method between the concrete truss members was proposed to accommodate fast assembly and disassembly. Full-scale test of PCT system was performed to verify the load-carrying capacity of the PCT system including the connections. The test results were compared with those of structural analysis. The test specimen which corresponds to PCT strut attained the ultimate load without buckling, but the detail of connector members needs to be improved. It is expected that precast concrete truss members can be efficiently incorporated into a temporary structure for deep and large excavation by replacing conventional steel beams.

Influence of shear bolt connections on modular precast steel-concrete composites for track support structures

  • Mirza, Olivia;Kaewunruen, Sakdirat
    • Steel and Composite Structures
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    • v.27 no.5
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    • pp.647-659
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    • 2018
  • Through extensive research, there exist a new type of connection between railway bridge girders and steel-concrete composite panels. In addition to conventional shear connectors, newly developed blind bolts have been recently adopted for retrofitting. However, the body of knowledge on their influence and application to railway structures has not been thoroughly investigated. This study has thus placed a particular emphasis on the application of blind bolts on the Sydney Harbour Bridge as a feasible alternative constituent of railway track upgrading. Finite element modeling has been used to simulate the behaviours of the precast steel-concrete panels with common types of bolt connection using commercially available package, ABAQUS. The steel-concrete composite track slabs have been designed in accordance with Australian Standards AS5100. These precast steel-concrete panels are then numerically retrofitted by three types of most practical bold connections: head studded shear connector, Ajax blind bolt and Lindapter hollow bolt. The influences of bolt connections on load and stress transfers and structural behaviour of the composite track slabs are highlighted in this paper. The numerical results exhibit that all three bolts can distribute stresses effectively and can be installed on the bridge girder. However, it is also found that Lindapter hollow bolts are superior in minimising structural responses of the composite track slabs to train loading.

Numerical Study on the Joints between Precast Post-Tensioned Segments

  • Kim, Tae-Hoon;Kim, Young-Jin;Jin, Byeong-Moo;Shin, Hyun-Mock
    • International Journal of Concrete Structures and Materials
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    • v.19 no.1E
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    • pp.3-9
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    • 2007
  • This paper presents a numerical procedure for analyzing the joints between precast post-tensioned segments. A computer program for the analysis of reinforced concrete structures was run for this problem. Models of material nonlinearity considered in this study include tensile, compressive and shear models for cracked concrete and a model for reinforcing steel with smeared crack. An unbonded tendon element based on the finite element method, that can describe the interaction between the tendon and concrete of prestressed concrete member, was experimentally investigated. A joint element is newly developed to predict the inelastic behavior of the joints between segmental members. The proposed numerical method for the joints between precast post-tensioned segments was verified by comparison of its results with reliable experimental results.

Numerical simulation of seismic tests on precast concrete structures with various arrangements of cladding panels

  • Lago, Bruno Dal
    • Computers and Concrete
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    • v.23 no.2
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    • pp.81-95
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    • 2019
  • The unexpected seismic interaction of dry-assembled precast concrete frame structures typical of the European heritage with their precast cladding panels brought to extensive failures of the panels during recent earthquakes due to the inadequateness of their connection systems. Following this recognition, an experimental campaign of cyclic and pseudo-dynamic tests has been performed at ELSA laboratory of the Joint Research Centre of the European Commission on a full-scale prototype of precast structure with vertical and horizontal cladding panels within the framework of the Safecladding project. The panels were connected to the frame structure by means of innovative arrangements of fastening systems including isostatic, integrated and dissipative. Many of the investigated configurations involved a strong frame-cladding interaction, modifying the structural behaviour of the frame turning it into highly non-linear since small deformation. In such cases, properly modelling the connections becomes fundamental in the framework of a design by non-linear dynamic analysis. This paper presents the peculiarities of the numerical models of precast frame structures equipped with the various cladding connection systems which have been set to predict and simulate the experimental results from pseudo-dynamic tests. The comparison allows to validate the structural models and to derive recommendations for a proper modelling of the different types of existing and innovative cladding connection systems.

Quantitative Analysis on Effective Stiffness of Horizontal Joints in Precast Concrete Large Panel Structures (P.C. 대형판 구조물의 수평접합부 유효강성에 대한 정량적 분석)

  • 이한선;장극관;신영식
    • Magazine of the Korea Concrete Institute
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    • v.6 no.3
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    • pp.142-151
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    • 1994
  • Though stiffnesses of joints in precast concrete(P.C.) large panel structures are known to be generally less than those in monolithic reinforced concrete wall structures, designers have very little information on the quantitative values with regards to these stiffnesses. The aim of this paper is to provide this quantitative information, in particular, on the compressive stiffness of horizontal joints, based on the analytical results derived from several experiments. Also, it is shown that the approach from the contact problem to determine this stiffness gives a value very simlar to those obtained above.