| Project/Area Number |
13650626
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Building structures/materials
|
|---|
| Research Institution | KYOTO UNIVERSITY |
|---|
Principal Investigator |
TANAKA Hitoshi KYOTO UNIVERSITY, Disaster Prevention Research Institute, Professor, 防災研究所, 教授 (20132623)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
MOROOKA Shigehiro KYOTO UNIVERSITY, Disaster Prevention Research Institute, Research Associate, 防災研究所, 助手 (80273522)
NAKAJI Hiroyuki Toyohashi University of Technology, Faculty of Engineering, Research Associate, 工学部, 助手 (80314095)
|
|---|
| Project Period (FY) |
2001 – 2002
|
| Project Status |
Completed (Fiscal Year 2002)
|
| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2002: ¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 2001: ¥1,800,000 (Direct Cost: ¥1,800,000)
|
|---|
| Keywords | scale effects / reinforced concrete column / confined concrete / concentric loading test / stress-strain model / hoop reinforcement / seismic design / limit state design / コンクリート圧縮強度 / コンクリート応力-歪関係 / 横拘束筋 / 鉄筋コンクリート柱 / 高層住宅 |
|---|
| Research Abstract |
In this study, focusing on the scale effects, some concentric compression loading tests were conducted using square columns to obtain the compressive stress-strain relationships of confined and unconfined concrete. As the main experimental variable, the sectional width of the tested square columns was varied from 194mm to 600mm. It was found that, due to the significant scale effect, the strength of columns was reduced more than predicted by any of the previously proposed models. Based on these experimental results, modification of a previous stress-strain model for confined and unconfined concrete was proposed so as to be able to take the sectional dimensions of column into account. The adequacy of the modified model was examined by comparing with the experimental results from this study and also from other sources.
It is noted that, when only the safety limit state is considered in the column design, the strength reduction due to the scale effect might not be so significant especially for the case of concrete columns confined by closely spaced lateral reinforcement. This is because the ultimate limit state of such coned concrete columns is dominated by the details of lateral confining reinforcement rather than the characteristics of plain concrete. However, the strength reduction of concrete due to the scale effect could become crucial if the serviceability limit state and the damage control limit state are considered in the design. This is because the column damage level under such limit states is predominantly determined by the characteristics of unconfined cover concrete and core concrete with little confining stress.
|
