2022 Fiscal Year Final Research Report
Clarification on Shear Resisting Mechanics of Damaged Concrete Members Based on Micro-Structural Interactive Fracture Mechanics
| Project/Area Number |
19H02226
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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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| Review Section |
Basic Section 22020:Structure engineering and earthquake engineering-related
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| Research Institution | Kobe University |
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Principal Investigator |
MIKI Tomohiro 神戸大学, 工学研究科, 准教授 (30401540)
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| Co-Investigator(Kenkyū-buntansha) |
上田 尚史 関西大学, 環境都市工学部, 准教授 (20422785)
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| Project Period (FY) |
2019-04-01 – 2023-03-31
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| Keywords | 微視－構造連成破壊力学 / アルカリシリカ反応(ASR) / 水中圧縮疲労 / ひび割れ密度 / せん断スパン有効高さ比a/d / RCディープビーム / 圧縮破壊エネルギー / ケミカルプレストレス |
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| Outline of Final Research Achievements |
This study presents various investigations to clarify the shear resistance mechanism of concrete members deteriorated by alkali-silica reaction (ASR). In the elemental experiments, the effect of water on the crack propagation in the concrete damaged due to ASR under cyclic compressive loading was investigated. First, the degree of deterioration was quantified based on non-destructive tests, and compression fatigue tests of the concrete with various damaged levels in water-submerged conditions was performed. From the experiments, we particularly succeeded in experimentally capturing the increasing process of compressive strain during compressive cyclic loading in the submerged condition. In addition, the loading tests for the RC beams with different shear span effective height (a/d) ratios revealed that the effect of the diagonal cracking load, the angle and distribution of the diagonal cracks on the shear strength of the ASR-damaged RC beams with different a/d ratios was clarified.
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| Free Research Field |
コンクリート構造
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| Academic Significance and Societal Importance of the Research Achievements |
ASRによる劣化は「水」の影響を受けるため，同一構造物であっても桁端部や橋脚上部など，水の影響の多寡により損傷状態が異なる．また，ASRが生じたコンクリート部材では，コンクリート内在の損傷が空間的に分布するため，部材から採取したコアの力学特性と構造部材の特性を直接関連づけることができない課題がある．本研究の成果により，劣化状態の空間分布やばらつきを考慮して，内在損傷が外力によって生じるひび割れ進展自体や，部材の終局時に見られる破壊の局所化現象に及ぼす影響が明らかとなった．今後，部位の損傷状態やその程度に従って必要な箇所に絞って補強するといった，適切な補強対策が可能となると考えられる．
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