Effectiveness of nylon fiber recycled from fishing net as a repair material to restore structural capacity

2019 Fiscal Year Final Research Report

• Project/Area Number: 17H03293
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Structural engineering/Earthquake engineering/Maintenance management engineering
• Research Institution: Hokkaido University
• Principal Investigator: YOKOTA Hiroshi 北海道大学, 工学研究院, 教授 (50344312)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 廃棄漁網 / リサイクル / ナイロン繊維 / コンクリート構造物 / 補強材料 / 性能回復 / 力学性能 / 耐久性

Outline of Final Research Achievements

This research program focused on the effectiveness of recycled nylon fiber from used fishing nets as a reinforcing material of concrete and mortar. The addition of fiber results in the decrease in compressive strength of concrete because of fiber's low Young's modulus. The reduction in strength is observed to be lower with higher fiber fraction and longer fibers. The addition of fiber affords a more ductile mode of failure, which leads to an increase in the load carrying capacity of fiber reinforced mortar. In the experiment, #-shape shows high effectiveness because it enhances flexural performance of mortar. Durability against free-thaw repetitions and chloride ion invasion are enhanced by adding the fiber. The experimental results confirmed that recycled nylon fiber has the potential for effectively reinforcing concrete and mortar and would be a possible way to recycle them, which can realize sustainability in the world.

Free Research Field

コンクリート工学、維持管理工学

Academic Significance and Societal Importance of the Research Achievements

素材自体の力学性能が他の一般的な有機繊維と比較して十分ではないリサイクルナイロン繊維をコンクリート補修・補強材として用い、特にコンクリートの引張性能や耐久性を向上できる可能性が示されたことで、今後さらなる研究や実用化に向けた検討および技術開発が期待できる。このことは、有害物質を発生させるため焼却処分が難しいとされる廃棄漁網を回収してリサイクルするための選択肢を増やすこととつながり、海洋生物や海洋環境に与える悪影響を低減させ、地球環境の保全や温暖化の防止にも意義がある。