Adhesive durability of joint repair materials by underwater fatigue test that reproduces the expansion and contraction behavior of open channels

2021 Fiscal Year Final Research Report

• Project/Area Number: 20K22603
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0604:Agricultural economics and rural sociology, agricultural engineering, and related fields
• Research Institution: National Agriculture and Food Research Organization
• Principal Investigator: MORI Mitsuhiro 国立研究開発法人農業・食品産業技術総合研究機構, 農村工学研究部門, グループ長 (70414456)
• Project Period (FY): 2020-09-11 – 2022-03-31
• Keywords: コンクリート開水路 / 目地 / シーリング材 / 接着耐久性 / 疲労試験

Outline of Final Research Achievements

The new fatigue test simulating the expansion and contraction behavior of an open channel was conducted for sealants used for joint repair of a concrete open channel.The adhesive durability of three types sealants was evaluated in this fatigue test.The sealant molded to a joint width of 12 mm was expanded and contracted at ± 3 mm (± 25%) and 0.1 Hz in (1) aerial environment, (2) aerial environment after immersion in water, and (3) underwater environment.The initial values were the compression and tensile force during the first expansion and contraction.The retention rate was defined as the value obtained by dividing the compression and tensile force measured for each number of repetitions (logarithmic plot) by the initial value.As a result, in the developed underwater fatigue test (3), it was shown that the retention rate decreased with a smaller number of repetitions compared to (1) and (2).

Free Research Field

施設機能工学

Academic Significance and Societal Importance of the Research Achievements

農林水産省が監修している「農業水利施設の補修・補強工事に関するマニュアル【開水路補修編】（案）」には，シーリング材の品質規格として，水中浸漬後の気中環境での繰り返し試験が規定されている．本研究で試行した水中疲労試験は，水中浸漬後の気中環境下での試験よりも早期にはく離を発生させることができることから，水中における接着耐久性の新たな照査手法としての活用や，新材料開発時の接着耐久性確認方法として利用できると考えている．