1997 Fiscal Year Final Research Report Summary
Capacities of Reinforced Concrete Beam-Column Joints and the Deformation Characteristics of Frames
| Project/Area Number |
08455256
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Building structures/materials
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
FUJII Shigeru Department of Global Environment Engineering Kyoto University Associate Professor, 工学研究科, 助教授 (70144334)
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| Co-Investigator(Kenkyū-buntansha) |
SATO Yuichi Department of Global Environment Engineering, Kyoto University, Instructor, 工学研究科, 助手 (20293889)
KISHIMOTO Ichizo Department of Architectural Engineering, Osaka University, Instructor, 工学部, 助手 (40234215)
KONDO Goro Department of Architectural Engineering, Chiva University, Associate Professor, 工学部, 助教授 (30195896)
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| Project Period (FY) |
1996 – 1997
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| Keywords | reinforced concrete / beam-column joint / shear strength / seismic response / knee joints / bi-directional loading / database / ductility factor |
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| Research Abstract |
The following findings were obtained through the ersearch :
(1)Shear strength of various types of joints
Shear strengths of interior column-, exterior column-beam joints, T-shaped joints and knee joints were investigated experimenbtally. The strength ratio for these joints with appropriate anchorage details are 1 : 0.7 : 0.7 : 0.4 respectively. Especially for knee joints, the joint capacity is strongly dependent on the bar anchorage details and loading directions.
(2)Joint shear capacity under two directional loadings
Failure interaction curve of corner column-beam joints under bi-directional loadings can be modeled as a circle. Bi-directional loading history degrades the flexural capacity of the column due to the bond deterioration in corner longitudinal column bars.
(3)Statistical analysis of shear strength and ductility in interior column-beam sub-assemblage
Collecting a total of 332 data of previous joint shear experiments, the effects of several parameters on joint shear strength were a
… More
nalyzed. joint shear strength increases proportionally to sigma_B (sigma_B : concrete compressive strength). Ductillity factor is governed by the ratio of joint shear strength to the joint shear input corresponding to the beam flexural strength. The empirical equation was derived considering the effect of joint shear reinforcement and material strength.
(4)Seismic response of frame structures with various hysterisis characteristics.
Conducting the dynamic analysis for a identified single-mass model with various dumping characteristics, the effect of loss of energy dissipating capacity due to the bond-slip behavior and the degradation of joint shear resistance on the whole frame deformation characteristics was discussed. The future research needs on the hysterisis model and on the interaction between seismic power and allowable joint degradation were pointed out.
(5)Experimental study on the improvement of the joint capacity in high strength RC frames by hinge-relocation method
Arranging the additional beam longitudinal bars, which are passing through the joint, made the critical sections apart from column faces and kept joint elastic. Hinge relocation method is effective way to improve the joint capacities and to control the bond deterioration. Less
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