Development of non-destructive test of measuring the concrete crack depth

混凝土裂缝深度无损检测方法的研制

• 批准号: 12555079
• 负责人: HAGA Akira
• 金额: $ 2.24万
• 依托单位: Tohoku Gakuin University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12555079/
• 关键词: concrete; crack; non-destructive test; resonant frequency; input impedance; monopole antenna; exciting coil; コンクリートクラック; 導電性液体; 入力インピーダンス; V形励磁コイル; 瞬間強磁界

The main purpose in this study is to estimate the depth and inclination angle of a crack in concrete.1. Magnetic powders were packed into a crack and magnetized with E-form or V-form ferrite core with a pick-up coil centered between the exciting coils. The magnitude and phase of the magnetic flux caused by the core packed with magnetic powders were measured. The experimental results show that the inclination angle could be clearly recognizes, and depth of the crack was determined to be half distance of exciting coil.2. Conductive powders or liquid are packed into a crack and set up the ground plane of aluminum as thin as 2mm. N-type connector is mounted on a ground plane which inner conductor is in contact with conductive powders or liquid in a crack, and ground plane. Monopole antenna is composed of conductive material in a crack and ground plane. Input impedance of the monopole antenna was measured by network analyzer. The length of crack is odd number of quarter wavelength long, when the imaginary part will be zero.That isL = λ/4 = c/(4 × f_0 × √<ε_s> (1)where λ is wavelength , L is the length of crack, c is the velocity of light, f_0 is resonant frequency, and ε_s is relative permittivity.It is therefore possible to estimate the deep crack depth(1〜2m) in terms of the resonance frequencies.

本研究的主要目的是估计混凝土裂缝的深度和倾角.磁粉填充在裂缝中，并使用E形或V形铁氧体磁芯磁化，其中拾取线圈位于激励线圈之间。测量了填充磁粉的磁芯产生的磁通量的大小和相位。实验结果表明，可以清晰地识别出倾斜角度，并确定裂纹深度为激励线圈距离的一半。导电粉末或液体填充到裂缝中，并设置薄至2 mm的铝接地层。N型连接器安装在接地平面和接地平面上，接地平面的内导体与裂缝中的导电粉末或液体接触。单极子天线是由导电材料在裂缝和接地平面。利用网络分析仪测量了单极天线的输入阻抗。当虚部为零时，裂纹长度为四分之一波长的奇数倍，即L = λ/4 = c/（4 × f_0 × ε_s）（1）式中λ为波长，L为裂纹长度，c为光速，f_0为共振频率，ε_s是相对介电常数，因此可以用共振频率来估计深裂纹深度（1 ~ 2 m）。

项目成果

T.Tmamura, A.Haga, K.Otsuka and H.Matsukio: "Magnetically Non-destructive Inspection of Concrete-crack by Using V-core"2000 Tohoku-Section join Convention Record of Institute of Electrical and Information Engineers, Japan. (2000)

T.Tmamura、A.Haga、K.Otsuka 和 H.Matsukio：“使用 V 型芯对混凝土裂缝进行磁力无损检测”2000 年东北部分加入日本电气和信息工程师协会会议记录。

A.Haga and K.Otsuka: "Electrically Non-destructive Inspection of Concrete-crack"Patent. 2001-161422. (2001)

A.Haga 和 K.Otsuka：“混凝土裂缝的电气无损检测”专利。

梶山知宏, 芳賀 昭, 塩川孝泰, 奈須野 裕, 松木英敏: "モノポールアンテナ動作によるコンクリートクラックの深さの測定法の検討"電気学会全国大会. 1-202. (2003)

Tomohiro Kajiyama、Akira Haga、Takayasu Shiokawa、Yutaka Nasuno、Hidetoshi Matsuki：“使用单极天线操作测量混凝土裂缝深度的方法的研究”日本电气工程师学会全国会议（2003）。

"コンクリートクラックの電気的非破壊検査法"東北学院大学工学部研究報告. 37. 9-13 (2003)

“混凝土裂缝的电无损检测方法”东北学院大学工学部研究报告37. 9-13 (2003)。

A.Haga, K.Otsuka, M.Sitou, S.Takahashi, H.Nasuno, and H.Matsuki: "Nondestructive Magnetic Measurement of the Depths of Cracks In Concrete"J. of the Magnetic Society of Japan. Vol.27, No.4-2. 1537-1540 (1999)

A.Haga、K.Otsuka、M.Sitou、S.Takahashi、H.Nasuno 和 H.Matsuki：“混凝土裂缝深度的无损磁测量”J。