1988 Fiscal Year Final Research Report Summary
Verification of Macroscopic Models for Reinforced Concrete Beam-Column Joints and Development of Aseismic Design Method
| Project/Area Number |
62550410
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Building structures/materials
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| Research Institution | Chiba University |
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Principal Investigator |
NOGUCHI Hiroshi Associate Professor, Faculty of Engineering, Chiba University, 工学部, 助教授 (20107535)
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| Project Period (FY) |
1987 – 1988
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| Keywords | Reinforced concrete / Beam-column joint / Shear resistance mechanisms / Limit deformation / Bond / せん断 |
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| Research Abstract |
The test of reinforced concrete interior beam-column joint was carried out with the emphasis on the bond characteristics of beam longitudinal bars passing through a joint and the maximum shear stress in a joint under reversed cyclic loading in 1987.
The test results were compiled and discussed in 1988. The deterioration process of a joint in the experiment was investigated in detail with the emphasis on the relationship between high shear strength in a joint failure type and comparatively low shear strength in a shear compression failure type after beam flexural yielding. Fur-thermore story drift and shear deformation of a joint were investigated and their ef-fects on beam longitudinal reinforcement were examined.
The test results were as follows.
1) As for the relationship between the maximum shear strength and story drift angle, the story drift angle was smaller as the input shear stress increased. The story draft angle was about 1/50rad at pu=0.3Fc, and about 1/25rad at pu=0.4Fc.
2) The compression failure of a joint was observed before the maximum strength, and a difference of the deformations between at the time of compression failure and at the time of the maximum strength was larger as the shear input stress increases.
3) The story draft angle when the strain in the concrete strut of a joint reached at the strain at the maximum strength was 1/50rad at pu=0.4Fc, and the effects of bond characteristics of beam longitudinal bars were not observed. But at pu=0.35Fc, the story draft angle was 1/45rad for the specimens with good bond for beam bar and 1/36rad for the specimens with poor bond. It was observed that the stress flowed widely in a joint and the deformation capability increased, when the input shear stress was low and the bond of beam bars was good.
The experiment in which a change of the limit deformation curve by a difference of the joint shear reinforcement ratio is observed is necessary.
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