A Developmental Study on the Anchor Bolts with Filling Cement Mortar Installed in Cracked Concrete

开裂混凝土中填充水泥砂浆锚栓的研制

• 批准号: 07650681
• 负责人: KAWAMURA Hiroyuki
• 金额: $ 1.09万
• 依托单位: KYUSHU SANGYO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07650681/
• 关键词: post installed anchor; pull out strength; shear strength; crack; resin grouting

The following properties of the post-installed concrete anchor in a dented bore of concrete with filling cement mortar were clarified as achievement of this study.(1) We can estimate the tensile strength of this anchor installed in a cracked concrete member by using the project area cut at cracks instead of the whole project area of the failure cone in the present standard and the guide. But cracks can be neglected in the case in which the depth of each crack is less than 1/3 of the embedded depth of the anchor.(2) The tensile strength of this anchor installed in the concrete member with cracks injected with epoxy resin recovers to the one instalied in the concrete member with no crack.(3) In order to increase the tensile strength of this anchor when we force the anchor to install in deteriorated and low strength concrete members, To substitute the low strength concrete within the diameter equal to the embedded depth and the same embedded depth of the anchor for the high strength cement mortar or to inject the epoxy resin into the cylindrical grove near the anchor bolt are most effective.(4) From results of the shear test of beam-wall joints which are made from a cracked beam installed with these anchors and a increased wall, If the beam installed with anchors are cracked, the shear strength decrease 15% compared with non cracked beams, but these is no difference in shear strength according to quantity of cracks. Also the shear strength increase slightly when epoxy resin injected into cracks of the beam.

本文的研究成果明确了水泥砂浆填充混凝土凹孔后安装混凝土锚杆的以下性能。(1)在裂缝混凝土构件中，锚杆的抗拉强度可以用裂缝处的工程面积来估算，而不是现行标准和指南中采用破坏锥的整个工程面积来估算。但当裂缝深度小于锚杆埋深的1/3时，裂缝可忽略不计。(2)安装在裂缝混凝土构件中的锚杆经环氧树脂注入后抗拉强度恢复到安装在无裂缝混凝土构件中的锚杆抗拉强度。(3)为了提高该锚杆在劣化低强度混凝土构件中强制安装时的抗拉强度，在与锚杆埋深相同的直径内，用高强度水泥砂浆代替与锚杆埋深相等的低强度混凝土，或在锚杆附近的圆柱形凹槽内注入环氧树脂是最有效的方法。(4)从安装锚杆的裂缝梁与加厚墙体组成的梁墙节点抗剪试验结果来看，安装锚杆的裂缝梁与未裂缝梁相比，抗剪强度降低15%，但裂缝数量不同，抗剪强度无差异。在裂缝处注入环氧树脂后，梁的抗剪强度略有提高。

项目成果

Hiroyuki KAWAMURA: "Tensile Strength of a Post Installed Anchor Bolts on Cracked Concrete" Transactions of the Japan Concrete Institute. Vol.18. 581-586 (1996)

Hiroyuki KAWAMURA：“开裂混凝土上后安装锚栓的拉伸强度”日本混凝土协会汇刊。

矢野哲也: "低強度コンクリートに施工するあと施工アンカーの引抜耐力増強法について" 日本建築学会九州支部研究報告. 36号構造系. 445-448 (1997)

Tetsuya Yano：“关于提高低强度混凝土后安装锚杆的拉拔强度的方法”日本建筑学会九州分会研究报告第36号结构系统（1997年）。