担当区分：最終著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： 10.2208/jscejj.23-16045

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.cscm.2024.e02984

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.11395/aem.8.0_62

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担当区分：最終著者   記述言語：英語   掲載種別：論文集(書籍)内論文   出版者・発行元：Springer Nature Switzerland  

DOI： 10.1007/978-3-031-33465-8_75

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担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：論文集(書籍)内論文   出版者・発行元：Springer Nature Switzerland  

DOI： 10.1007/978-3-031-33465-8_59

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担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：{MDPI} {AG}  

<jats:p>This research investigates the influence of the pre-existing defects within concrete taken from the in-service irrigation structure on the strain distribution. The X-ray Computed Tomography (CT) technique is employed to investigate the internal concrete matrix and evaluate the defect distribution in it. The cracking system in a concrete matrix is detected as a damage type caused by the severe environment, and it is varied by the different degrees in all samples. The geometric properties of defects and their spatial location are obtained by image processing of CT images. The compression test with Acoustic Emission (AE) and Digital Image Correlation (DIC) measurements is conducted to analyze the fracture processes and acquire the damage spatial information. The AE signal descriptors are effective parameters for real-time detection and potential local damage monitoring. Moreover, the analysis of the DICM strain and displacement fields reveals the most potential fracture zones. The AE source location analysis indicated a connection between pre-existing defects and strain localization. The AE events and strain are high in the defect areas. Additionally, the amplitude and frequency of the AE events correlated with the location of the defects indicating that the structure weakness at that point leads to concentrated deformation development.</jats:p>

DOI： 10.3390/app13116727

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担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier {BV}  

DOI： 10.1016/j.cscm.2023.e02088

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担当区分：最終著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： 10.2472/jsms.72.188

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担当区分：最終著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： 10.11408/jsidre.91.I_57

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担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media {LLC}  

DOI： 10.1007/s10333-022-00910-w

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その他リンク： https://link.springer.com/article/10.1007/s10333-022-00910-w/fulltext.html

担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Frontiers Media {SA}  

<jats:p>Steel sheet pile materials are primarily used for canal structure construction for irrigation and drainage of agricultural fields in Japan. Recently, accelerated corrosion of steel materials and buckling phenomena in pitting corrosion parts have been detected in in-service steel sheet pile canals. In this study, we focus on the buckling phenomenon of in-service steel sheet pile canals, which is detected by non-contact monitoring using digital image analysis. The buckling phenomenon index is evaluated as the inclination angle of the steel sheet pile due to deformation. As a digital image analysis, Hough transform is applied, which is a figure detection method in digital images, to detect a straight line that describes the distance and angle parameters. The angle parameter corresponds to the inclination angle index of in-service steel sheet pile with a buckling phenomenon. As a result, the maximum difference between the analyzed angles by Hough transform and the measured angles is evaluated as 0.9° after the image rotation correction. The relation of the analyzed angles by Hough transform and the measured angles of the buckling phenomenon is correlated. Therefore, the degradation of steel sheet pile canals is quantitatively evaluated by using digital image analysis with unmanned aerial vehicle monitoring. This study’s significance is non-contact and simple measurement by using a digital image which can reduce a working time and perform quick diagnosis in extensive areas.</jats:p>

DOI： 10.3389/fbuil.2022.948232

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担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Frontiers Media {SA}  

<jats:p>The durability of concrete irrigation infrastructures decreases easily due to environmental effects, such as the freeze-thawed process. The degree of damage in concrete is, in most cases, evaluated by an unconfined compression test or ultrasonic test. The limiting states of structures are the result of a gradual accumulation of microdefects during the in-service period, which leads to the initiation and development of macroscopic cracks, loss of performance, and Failure. Therefore, to maintain such structures, it is necessary to properly determine the degree of damage by non-destructive testing. For effective maintenance and management of in-service structures, it is necessary to evaluate not only such mechanical properties as strength but also the degree of damage. Quantitative damage evaluation of concrete is proposed by applying the X-ray CT method and related non-destructive inspection, which is based on estimating cracking damage effects. In this study, the damage evaluation of concrete-core samples is investigated by X-ray CT parameters and the non-destructive parameters. The samples tested were taken from the damaged concrete headwork in Niigata, Japan, about 50 years after its construction. The geometric properties of the concrete matrix were calculated by the analysis of X-ray CT images. After X-ray CT measurement, an ultrasonic test and a resonant frequency test were performed. The dynamic modulus of elasticity was calculated by using ultrasonic pulse velocity and resonant frequency. As a result, based on the relationship between the geometric properties of the concrete matrix and the non-destructive parameters, the accumulation of damage in the samples tested was correlated with the ratio of the total area of cracks to the observation area. In damaged conditions, the high value of its ratio is demonstrated under low ultrasonic pulse velocity. These results suggest that the most sensitive components in a concrete body to the degree of damage are cracks in mortar and the ratio of the total area of cracks to the observation area. These values are affected by the internal actual cracks. Thus, the damage of concrete could be quantitatively evaluated by the geometric properties of the concrete matrix and its physical properties.</jats:p>

DOI： 10.3389/fbuil.2022.947759

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担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Japanese Society of Agricultural, Biological and Environmental Engineers and Scientists  

DOI： 10.2525/ecb.60.161

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記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： 10.11408/jsidre.90.I_239

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担当区分：最終著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： 10.11408/jsidre.89.I_1

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担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.11395/aem.5.0_122

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担当区分：最終著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： 10.11408/jsidre.88.I_59

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担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier {BV}  

DOI： 10.1016/j.conbuildmat.2020.118343

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担当区分：筆頭著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： 10.11408/jsidre.88.I_67

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記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： 10.11408/jsidre.88.I_145

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担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media {LLC}  

DOI： 10.1007/s10333-019-00752-z

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担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/s10333-019-00726-1

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担当区分：最終著者,　責任著者   記述言語：日本語  

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担当区分：筆頭著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： 10.11408/jsidre.84.I_317

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media {LLC}  

DOI： 10.1617/s11527-015-0672-9

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担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：論文集(書籍)内論文   出版者・発行元：Springer Netherlands  

For detailed inspections of concrete structures, non-destructive tests (NDT) are often conducted and then mechanical properties are compared with detected NDT parameters. In this chapter, damage evaluation of concrete by AE and X-ray computerized tomography (CT) tests are presented. The concrete damage is visualized by X-ray CT. Since nucleation of AE events in damaged concrete is affected by crack distribution, the damage parameter estimated is correlated with the dynamic modulus of elasticity Ed which is calculated from P-wave velocity. The results confirm that the damage of concrete could be estimated by applying AE measurement, damage parameter in damage mechanics, CT images and modulus Ed. It is also shown that the static modulus E0 is closely correlated with the dynamic modulus Ed. Based on a relation between AE rate and the damage parameter, the damage of concrete is quantitatively estimated.

DOI： 10.1007/978-94-017-7606-6_9

Scopus

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担当区分：責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）  

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担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCI LTD  

The Great East-Japan Earthquake hit Tohoku area in Japan on March 11, 2011. A large number of concrete structures were damaged due to the 9.0 magnitude earthquake of the Richter-scale. Prior to reconstruction and retrofit of these structures, damage evaluation of in situ concrete structures is now in urgent demand. In this concern, quantitative damage estimation of concrete is proposed to be performed, applying acoustic emission (AE) measurement in a uniaxial compression test of core samples. Generating behavior of AE events in the core test is quantitatively analyzed, based on the rate process theory, because notable discrepancy of AE activity is observed between damaged concrete and undamaged concrete. The damage is quantitatively defined by a scalar damage parameter in damage mechanics. Correlating AE rate with the damage parameter, quantitative estimation of damage is proposed in terms of the relative modulus of elasticity (E-0/E*). Concrete core samples were taken from reinforced concrete columns of an existing canal in the both periods of pre and post the earthquake. Prior to the compression test, distribution of microcracks in a concrete-core sample was inspected by helical X-ray computed tomography (CT), which scans at 1-mm intervals. The results suggest that the damage of concrete could be quantitatively estimated from damage parameter E-0/E* without knowing the original state of the concrete at construction. The static moduli E-0/E* and dynamic moduli E-d/E* is closely correlated. A relation between AE rate and the damage parameters is correlated, and thus the earthquake damage of concrete is quantitatively estimated using AE. (C) 2014 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.conbuildmat.2014.05.016

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担当区分：責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Japan Society of Civil Engineers  

近年，鋼矢板を用いた農業用開水路の早期腐食に伴う耐久性低下が技術的問題となっている．本報では，既設鋼矢板にコンクリート被覆を施した複合材の曲げ載荷時の力学特性評価を試みた結果を報告する．検討にはAE法とデジタル画像相関法（DICM）を用いた．試験体は，既設鋼矢板，コンクリートおよびプレキャストパネルの三層で構成されている．検討の結果，試験体の変形挙動は，AEやDICMの試験パラメータを用いることにより評価可能であることが明らかになった．鋼矢板‐コンクリート複合材の変形挙動は，鋼矢板の凸凹形状に起因すると考えられるねじれ現象と密接に関連していることが示唆された．

DOI： 10.2208/jscejam.70.I_81

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担当区分：責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Japan Society of Civil Engineers  

パイプランの効果的な維持管理や安全性診断には，管材損傷に加えて水撃圧に代表される圧力波の検出が不可欠である．本報では，事故後復旧過程の非破壊安全性診断に資する圧力波の非破壊検出について検討した結果を報告する．計測にはAE（Acoustic Emission）法と画像解析を用いた．実験的検討の結果，圧力波は制水弁閉塞時間を0.40～10.48sに調整したモデルパイプラインにおいてAE法と画像解析で検出された．圧力波のAE発生挙動は，水圧の最大値と関連し，AEパラメータにより評価可能であることが明らかになった．デジタル画像相関法（DICM）により画像解析を行った結果，最大水圧と管体変位量に関連性が確認された．これらの結果から，発生した圧力波はAE法や画像解析により検出可能であることが示され，現状において計測が困難であった配管内の圧力波を非破壊計測により検出可能であることが明らかになった．

DOI： 10.2208/jscejsp.70.I_143

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担当区分：筆頭著者,　責任著者  

DOI： 10.2208/jscejsp.69.I_49

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担当区分：筆頭著者,　責任著者   記述言語：日本語   出版者・発行元：The Japanese Society of Irrigation, Drainage and Rural Engineering  

パイプランの効果的な維持管理には，管材損傷に加えて水撃圧に代表される圧力波の検出が不可欠である．本報では，AE（Acoustic Emission）法と画像解析による圧力波の非破壊検出について検討した結果を報告する．実験的検討の結果，圧力波は制水弁閉塞時間を0.40～10.48sに調整したモデルパイプラインにおいてAE法と画像解析で検出された．圧力波のAE発生挙動は，水圧の最大値と関連し，AEパラメータにより評価可能であることが明らかになった．デジタル画像相関法（DICM）により画像解析を行った結果，最大水圧と管体変位量に関連性が確認された．これらの結果から，発生した圧力波はAE法や画像解析により検出可能であることが示された．

DOI： 10.11408/jsidre.81.479

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記述言語：日本語   掲載種別：研究論文（学術雑誌）  

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担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

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担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCI LTD  

As a detailed inspection of a concrete structure in service, core samples are usually drilled out and then mechanical properties are measured. In this study, damage estimation of concrete structures from core samples is developed, applying acoustic emission (AE) and X-ray computed tomography method. Concrete-core samples were taken from reinforced concrete of an existing canal. These samples are strongly damaged by freezing and thawing process. Crack distributions of concrete-core samples were inspected with helical Computerized Tomography (CT) scans, which were undertaken at 1-mm intervals. After helical CT scan, damage of testing samples was evaluated, based on fracturing behavior under compression and AE activity. AE behavior is dependent on the degree of damage, and could be approximated by applying the AE rate-process analysis and damage mechanics. AE generation behavior is associated with crack volume due to damage accumulation in concrete. The damage is quantitatively defined by a scalar damage parameter in damage mechanics. Applying the scalar damage parameter, quantitative estimation of damage is proposed in terms of relative modulus of elasticity which is named "durability index". By calculating the durability index, the initial damage of samples is estimated from AE database. The decrease in mechanical properties could be evaluated by comparing the average CT number with the durability index, both of which are affected by internal cracks generated. Thus, the damage of concrete structures is quantitatively evaluated by AE and X-ray computed tomography method. (C) 2010 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.conbuildmat.2010.05.005

Web of Science

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掲載種別：研究論文（学術雑誌）  

DOI： 10.1617/s11527-010-9640-6

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その他リンク： http://link.springer.com/article/10.1617/s11527-010-9640-6/fulltext.html

掲載種別：研究論文（学術雑誌）  

DOI： 10.1617/s11527-010-9639-z

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その他リンク： http://link.springer.com/article/10.1617/s11527-010-9639-z/fulltext.html

掲載種別：研究論文（学術雑誌）  

DOI： 10.1617/s11527-010-9638-0

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その他リンク： http://link.springer.com/article/10.1617/s11527-010-9638-0/fulltext.html

担当区分：最終著者   記述言語：日本語   出版者・発行元：農業農村工学会  

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担当区分：筆頭著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： 10.11532/structcivil.56A.665

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担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER  

It is widely reported and realized that durability of concrete decreases due to such effects, as salt and chemical attack, freezing and thawing, and carbonation and fatigue. In existing structures mechanical damage of concrete has been practically estimated from the strength by a compression test and a rebound hammer test. For effective maintenance of concrete structures, it is necessary to evaluate quantitatively not only the strength of concrete but also the degree of damage. Quantitative damage evaluation of structural concrete is proposed by applying acoustic emission (AE) technique and damage mechanics. Consequently, damage evaluation is conducted on concrete cores of an existing structure.
Core-samples were collected from an arch fragment of a reinforced concrete road bridge that had been in service for 87 years. Compressive strengths and Young's moduli were measured during the compression test along with AE measurement. Dynamic Young's moduli were also calculated from the longitudinal wave velocity. Thus the relative damages are quantitatively evaluated from static and dynamic Young's moduli and compared with results of AE rate-process analysis.

DOI： 10.1617/s11527-006-9133-9

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担当区分：筆頭著者,　責任著者  

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担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCI LTD  

In recent years, deterioration of concrete structures has been widespread and become a social problem. Because the durability of concrete structures decreases easily due to such external effects, as carbonation and freezing-thawing process, it has been important to evaluate not only the strength but also the damage of concrete. Thus, damage evaluation of structural concrete is developed, applying acoustic emission (AE) method. Damaged concrete samples are examined, based on fracturing behavior under unconfined compression. AE behavior of the concrete under compression is dependent on the degree of damage, and could be analyzed by the rate process analysis. Using Loland's model, a relationship between stress and strain is modeled, and a relation between the AE rate and the damage parameter is correlated. By calculating Young's modulus of the intact concrete from the database of this correlation, the relative damage of the concrete in an actual structure is successfully estimated. (C) 2003 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.conbuildmat.2003.10.009

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総ページ数：418p   記述言語：日本語

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担当区分：筆頭著者,　責任著者   記述言語：日本語   出版者・発行元：日本下水道協会  

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記述言語：日本語   出版者・発行元：農業農村工学会  

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担当区分：筆頭著者,　責任著者   記述言語：日本語   掲載種別：記事・総説・解説・論説等（商業誌、新聞、ウェブメディア）  

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担当区分：最終著者,　責任著者   記述言語：日本語   掲載種別：記事・総説・解説・論説等（商業誌、新聞、ウェブメディア）   出版者・発行元：環境新聞社  

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担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）  

CiNii Article

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担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語  

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記述言語：英語   会議種別：口頭発表（一般）  

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記述言語：英語   会議種別：口頭発表（一般）  

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記述言語：英語   会議種別：口頭発表（一般）  

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記述言語：英語  

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記述言語：英語  

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記述言語：英語   会議種別：口頭発表（一般）  

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記述言語：英語   会議種別：口頭発表（一般）  

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記述言語：英語   会議種別：口頭発表（一般）  

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記述言語：英語   会議種別：口頭発表（一般）  

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記述言語：英語   会議種別：口頭発表（一般）  

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記述言語：英語   会議種別：口頭発表（一般）  

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会議種別：ポスター発表  

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出願番号：特願2019-116075  出願日：2019年6月

公開番号：特開2021-001822  公開日：2021年1月

特許番号/登録番号：特許第7232520号 

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出願人：国立大学法人 新潟大学；株式会社福田組；株式会社 東邦アーステック

出願番号：特願2018-082990  出願日：2018年4月

公開番号：特開2019-190100  公開日：2019年10月

特許番号/登録番号：特許第6781894号 

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出願番号：特願2014-215274  出願日：2014年10月

公開番号：特開2016-080139  公開日：2016年5月

特許番号/登録番号：特許第6497693号  発行日：2016年5月

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出願番号：特願2012-222223  出願日：2012年10月

公開番号：特開2014-074654  公開日：2014年4月

特許番号/登録番号：特許第5688058号  発行日：2015年1月

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出願番号：特願2008-089146  出願日：2008年3月

特許番号/登録番号：特許第5211379号  発行日：2009年10月

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