Restoring-force model for reinforced concrete members failing in shear or bond after yielding

屈服后剪切或粘结失效的钢筋混凝土构件的恢复力模型

• 批准号: 14350301
• 负责人: ICHINOSE Toshikatsu
• 金额: $ 9.86万
• 依托单位: Nagoya Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14350301/
• 关键词: concrete; columns; size-effect; shear failure; restoring-force; epoxy resin; CT scanning; フーリエ解析; 柱; 塑性変形; ばらつき; エポキシ樹脂; 載荷履歴; 横補強筋; 繰り返し; 軸力; 圧縮破壊

The first objective of this study is to establish a restoring-force model for reinforced concrete members failing in shear after flexural yielding. Twenty specimens of reinforced concrete columns are tested under constant axial load. Test parameters were concrete strengths, amount of longitudinal and shear reinforcement, and the dimensions. Some of them had dimensions similar to actual columns, while the others had dimensions about a half of actual columns. Most of them failed in shear after cyclic inelastic load reversals. Piano wires were embedded in the specimens so that average transverse strains in the core concrete were measured. In some cases, core concrete strain was larger than several ten times of the strain in the transverse reinforcement. At the maximum deflection of some of the specimens, epoxy resin was injected. After the resin hardened, the specimens were unloaded. Then, CT scanning was conducted to obtain three-dimensional image of the cracks in each specimen. The results agreed with the measured strains in the core concrete. Such findings were utilized to propose a restoring-force model for reinforced concrete members failing in shear after flexural yielding.The second objective of this study is to establish a model for bond splitting failure in reinforced concrete. The specimen parameters include bar diameter, rib shape, cover thickness, and the presence/absence of confining reinforcement. The experimental results show that the size-effect is mainly attributable to brittle splitting cracks, and not to local crushing of concrete in front of the bar ribs. Based on this finding, we proposed equations that yield a large size effect for splices with small cover and short splice length, where brittle failure is expected. The proposed equations agree with both the experimental results presented in this study and the bulk of the experimental data reported in the literature.

本研究的第一个目的是建立钢筋混凝土构件弯曲屈服后发生剪切破坏的恢复力模型。对20根钢筋混凝土柱进行了恒定轴压试验。试验参数为混凝土强度、纵向钢筋和抗剪钢筋的数量以及尺寸。其中一些尺寸与实际柱相似，而另一些尺寸约为实际柱的一半。在反复非弹性荷载作用下，大部分试件发生剪切破坏。钢琴线嵌入在试样中，以便在核心混凝土的平均横向应变进行测量。在某些情况下，核心混凝土应变大于横向钢筋应变的几十倍。在一些试样的最大挠度处，注入环氧树脂。在树脂硬化后，将试样卸载。然后，进行CT扫描以获得每个试样中的裂纹的三维图像。计算结果与实测的核心混凝土应变基本一致。利用这一研究结果，提出了一个钢筋混凝土构件弯曲屈服后剪切破坏的破坏力模型。本研究的第二个目的是建立一个模型，在钢筋混凝土粘结劈裂破坏。试件参数包括钢筋直径、肋形状、保护层厚度以及是否存在约束钢筋。试验结果表明，尺寸效应主要是由脆性劈裂引起的，而不是由肋前混凝土的局部压碎引起的。基于这一发现，我们提出了方程，产生一个大的尺寸效应的拼接与小的覆盖和短拼接长度，预计脆性破坏。所提出的方程与本研究中提出的实验结果和文献中报道的大量实验数据一致。

项目成果

耐力低下を考慮した鉄筋コンクリート建物の倒壊率

考虑强度降低的钢筋混凝土建筑物倒塌率

• 发表时间: 2005
• 期刊: コンクリート工学年次論文報告集 Vol.27, No.2
• 作者: 丸橋奈々子;高橋憲之;市之瀬敏勝;梅村恒
• 通讯作者: 梅村恒

The Factors Which Influence Strength Deterioration of RC Columns Failing in Shear after Flexural Yielding

影响RC柱弯曲屈服剪切破坏强度劣化的因素

• 发表时间: 2005
• 期刊: Journal of Structural and Construction Engineering(Transactions of AIJ) No.593
• 作者: Nobuaki Hanai;Toshikatsu Ichinose;Hisashi Umemura
• 通讯作者: Hisashi Umemura

梅村恒, 市之瀬敏勝, 松澤敦行: "載荷履歴と中子筋の有無がRC部材の復元特性に及ぼす影響"コンクリート工学年次論文報告集. 25・3(CD-ROM). (2003)

Tsune Umemura、Toshikatsu Ichinose、Atsuyuki Matsuzawa：“荷载历史和存在或不存在核心钢筋对 RC 构件恢复特性的影响”混凝土工程年度论文报告 25・3（CD-ROM）（2003 年）。

Evaluation of Shear Behavior on RC Columns based on Mohr-Coulomb's Failure Criterion

基于莫尔-库仑破坏准则的钢筋混凝土柱抗剪性能评估

• 发表时间: 2006
• 期刊: Proceedings of the Japan Concrete Institute No.28
• 作者: Nobuaki Hanai;Masataka Hirabayashi;Toshikatsu Ichinose
• 通讯作者: Toshikatsu Ichinose

異形鉄筋の付着割裂破壊に関する解析的研究

变形钢筋粘结劈裂破坏分析研究

• 发表时间: 2004
• 期刊: 日本建築学会構造系論文集 No.586
• 作者: 小椋紀行;市之瀬敏勝
• 通讯作者: 市之瀬敏勝