• Title/Summary/Keyword: concrete codes

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Statistical calibration of safety factors for flexural stiffness of composite columns

  • Aslani, Farhad;Lloyd, Ryan;Uy, Brian;Kang, Won-Hee;Hicks, Stephen
    • Steel and Composite Structures
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    • v.20 no.1
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    • pp.127-145
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    • 2016
  • Composite column design is strongly influenced by the computation of the critical buckling load, which is very sensitive to the effective flexural stiffness (EI) of the column. Because of this, the behaviour of a composite column under lateral loading and its response to deflection is largely determined by the EI of the member. Thus, prediction models used for composite member design should accurately mirror this behaviour. However, EI varies due to several design parameters, and the implementation of high-strength materials, which are not considered by the current composite design codes of practice. The reliability of the design methods from six codes of practice (i.e., AS 5100, AS/NZS 2327, Eurocode 4, AISC 2010, ACI 318, and AIJ) for composite columns is studied in this paper. Also, the reliability of these codes of practice against a serviceability limit state criterion are estimated based on the combined use of the test-based statistical procedure proposed by Johnson and Huang (1997) and Monte Carlo simulations. The composite columns database includes 100 tests of circular concrete-filled tubes, rectangular concrete-filled tubes, and concrete-encased steel composite columns. A summary of the reliability analysis procedure and the evaluated reliability indices are provided. The reasons for the reliability analysis results are discussed to provide useful insight and supporting information for a possible revision of available codes of practice.

Seismic behavior of non-seismically designed eccentric reinforced concrete beam-column joints

  • Liu, Ying;Wong, Simon H.F.;Zhang, Hexin;Kuang, J.S.;Lee, Pokman;Kwong, Winghei
    • Earthquakes and Structures
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    • v.21 no.6
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    • pp.613-625
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    • 2021
  • Non-seismically designed eccentric reinforced concrete beam-column joints were extensively used in existing reinforced concrete frame buildings, which were found to be vulnerable to seismic action in many incidences. To provide a fundamental understanding of the seismic performance and failure mechanism of the joints, three 2/3-scale exterior beam-column joints with non-seismically designed details were cast and tested under reversed cyclic loads simulating earthquake excitation. In this investigation, particular emphasis was given on the effects of the eccentricity between the centerlines of the beam and the column. It is shown that the eccentricity had significant effects on the damage characteristics, shear strength, and displacement ductility of the specimens. In addition, shear deformation and the strain of joint hoops were found to concentrate on the eccentric face of the joint. The results demonstrated that the specimen with an eccentricity of 1/4 column width failed in a brittle manner with premature joint shear failure, while the other specimens with less or no eccentricity failed in a ductile manner with joint shear failure after beam flexural yielding. Test results are compared with those predicted by three seismic design codes and two non-seismic design codes. In general, the codes do not accurately predict the shear strength of the eccentric joints with non-seismic details.

Maximum Shear Reinforcement of RC Beams using High Strength Concrete (고강도 콘크리트를 사용한 RC보의 최대철근비)

  • Lee, Jung-Yoon;Hwang, Hyun-Bok
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.839-842
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    • 2008
  • The ACI 318-05 code requires the maximum amount of shear reinforcement in reinforced concrete (RC) beams to prevent possible sudden shear failure due to over reinforcement. The design equations of the maximum amount of shear reinforcement provided by the current four design codes, ACI 318-05, CSA-04, EC2-02, and JCI-99, differ substantially from one another. The ACI 318-05, CSA-04, and EC2-02 codes provide an expression for the maximum amount of shear reinforcement ratio as a function of the concrete compressive strength, but Japanese code does not take into account the influence of the concrete compressive strength. For high strength concrete, the maximum amount of shear reinforcement calculated by the EC2-02 and CSA-04 is much greater than that calculated by the ACI 318-05. This paper presents the effects of shear reinforcement ratio and compressive strength of concrete on the maximum shear reinforcement in reinforced concrete beams. Ten RC beams having various shear reinforcement ratio were tested. Although the test beams were designed to have much more amount of shear reinforcement than that required in the ACI 318-05 code, all beams failed due to web concrete crushing after the stirrups reached the yield strain.

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Strength Evaluation of RC Beams Using Grid Strut-Tie Models (격자 스트럿-타이 모델을 이용한 철근콘크리트 보의 강도평가)

  • Yun Young Mook;Lee Won Seok;Kim Byung Hun;Jung Chan Heak
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.05a
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    • pp.540-543
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    • 2004
  • In this study, the validity of the grid softened strut-tie model method suggested for concrete member analysis is examined through the ultimate strength evaluation of the reinforced concrete beams. The evaluated results of ultimate strength by the grid softened strut-tie model method were compared with those by the ACI 318-02 and the modified compression field theory, and European codes.

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Joint Shear Failure of Reinforced Concrete Interior Beam-Column Joint (내부 보-기둥 접합부의 전단파괴)

  • 이민섭;홍성걸
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.10a
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    • pp.303-308
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    • 2000
  • The design of column joint is an important part of earthquake resistant design of reinforced concrete moment resisting frames. Beam column joints must provide sufficient stiffness and strength to resist and sustain the loads induced by adjacent beams and columns. This paper investigates the difference of the current design codes which provide a different approach for the design of beam column joint in seismic zone. The model provided by Hitoshi Shiohara(1998) is reviewed in this paper, which provides a good relationship between moment and shear action of interior beam column joint and a role shear reinforcement according to their position.

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Design Method of Large-Scale Concrete-Steel Composite Drilled Shafts (대구경 합성강관말뚝 설계 기법에 관한 연구)

  • Choi, Kyu-Yong;Yang, Jong-Ho;Choi, Seok-Hwan
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.05a
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    • pp.299-302
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    • 2005
  • Generally, steel-concrete composite structures are considered very useful and powerful to resist external axial and flexural load due to its elevated capacity originated from composite action. This usefulness of composite structures can be applied to the drilled shafts of marine bridges that require large-scale such as entire pile-column system. As the basic study of this application, several design codes are analyzed and compared in this research.

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Overview of Performance-Based Seismic Design of Building Structures in China

  • Li, Guo-Qiang;Xu, Yan-Bin;Sun, Fei-Fei
    • International Journal of High-Rise Buildings
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    • v.1 no.3
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    • pp.169-179
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    • 2012
  • The development history, the current situation and the future of the performance-based seismic design of building structures in China are presented in this paper. Firstly, the evolution of performance-based seismic design of building structures specified in the Chinese codes for seismic design of buildings of the edition 1974, 1978, 1989, 2001 and 2010 are introduced and compared. Secondly, in two parts, this paper details the provisions of performance-based seismic design in different Chinese codes. The first part is about the "Code for Seismic Design of Buildings" (GB50011) (edition 1989, 2001 and 2010) and "Technical Specification for Concrete Structures of Tall Building", which presents the concepts and methods of performance-based seismic design adopted in Chinese codes; The second part is about "Management Provisions for Seismic Design of Outof-codes High-rise Building Structures" and "Guidelines for Seismic Design of Out-of-codes High-rise Building Structures", which concludes the performance-based seismic design requirements for high-rise building structures over the relevant codes in China. Finally, according to those mentioned above, this paper pointed out the imperfections of current performance-based seismic design in China and proposed the possible direction for further improvement.

Current Situation and Future Prospects of Construction Technologies in North Korea (북한의 건설기술 현황 및 향후 정책 방향)

  • Byun, Keun-Joo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.825-834
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    • 2008
  • The safety, serviceability, and design code of the infrastructures such as highway, railroad, bridges, etc. have been analyzed. It is identified that the safety and function of infrastructures in North Korea could have some problems compared with current design codes. After analyzing the results, the multi-step road map for integrating infrastructures in Korea Peninsula is proposed.

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Condition Assessment Criteria for Bridges (교량의 외관상태평가 기준 정립에 대한 연구)

  • 오병환;신경준;이상철
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.10b
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    • pp.1285-1290
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    • 2000
  • The inspection of bridge condition is of extreme importance. Current inspection codes for bridge inspection are vague and uncertain. So, the results are highly subjective and different from person to person and even day to day for a given person. To circumvent possible inconsistencies in inspection and rating of bridge components, the revised inspection guidelines have been proposed.

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A Study on the Service Life Prediction of Reinforced Concrete Structures with Chloride Penetration (철근콘크리트 구조물의 염해에 의한 사용수명 예측에 관한 연구)

  • Kim Dong-Baek;Kwon Ki-Jun;Park Byung-Wook
    • Journal of the Korean Society of Safety
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    • v.20 no.2 s.70
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    • pp.113-118
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    • 2005
  • Recently, the corrosion of reinforced concrete structures has received great attention related with the deterioration of sea-side structures, such as new airport, bridges, and nuclear power plants. In this regards, many studies have been done on the chloride attack in concrete structures. The purpose of the present study is to explore the influences of chloride attack parameters to service life of reinforced concrete structures and to propose the rational program for the guarantee of service life. for this purpose, several codes for durability design have been examined and the diffusion analysis based on Fick's second law has been performed with various parameter value. The present study indicates that durability design code of Japan Society of Civil Engineers is more rational than other codes but the application of durability design code of JSCE to domestic durability design needs more studies to the various parameter values related with chloride penetration.