Development of X-ray CT image measurement method for local deformation in concrete

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K06522
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Civil engineering materials/Construction/Construction management
• Research Institution: Kindai University
• Principal Investigator: Takayuki Fumoto 近畿大学, 理工学部, 准教授 (30315981)
• Co-Investigator(Kenkyū-buntansha): 岩月 栄治 愛知工業大学, 工学部, 教授 (10278228) ; 三方 康弘 大阪工業大学, 工学部, 教授 (60434784)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: コンクリート / X線CT / 画像相関法 / 体積ひずみ / 圧縮応力 / 乾燥収縮 / アルカリ骨材反応 / 凍結融解

Outline of Final Research Achievements

For short-period deformation measurement inside the specimen such as compression loading, we have developed a jig with fixed balls to attach on the loading plate due to reduce mechanical errors during scanning. We also developed a jig to be attached directly on the specimen for long-period measurement of internal deformation such as drying shrinkage and ASR. On the other hand, the internal volumetric strain is calculated from the displacement difference between the adjacent measurement positions calculated by the digital volume correlation. That volumetric strain had sufficient accuracy without the jig because the difference reduces the error. As the results, an X-ray CT image measurement method for measuring local shrinkage and expansion deformation inside the concrete specimen in the short-term and long-term was established.

Free Research Field

コンクリート工学

Academic Significance and Societal Importance of the Research Achievements

本研究の成果としてX線CT装置で活用できる供試体内部の変形手法を開発した．例えば近畿大学のX線CT装置は，使用材料の粒子が大きいコンクリート試験体内部での挙動を計測するために，解像度0.062mm程度で，直径100mmの3次元画像を得られる．これにより，コンクリート分野で一般的に使用される直径100mmの供試体を用いて，応力変形，乾燥収縮，ASR膨張，凍結融解等の状況下で生じる供試体内部で体積変化を可視化することができ，表面から劣化が生じる現象のより深い理解に繋がる．そして，その結果は，FEM等による解析での現象の再現やより適切な構造設計や維持管理にも応用できると期待される．