リチウム含有HPFRCCを陽極システムに用いた電気化学的リハビリテーション手法に関する研究  [in Japanese] STUDY ON ELECTROCHEMICAL REHABILITATION METHOD USING HPFRCC CONTAINING LITHIUM SALT  [in Japanese]

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Author(s)

    • 上田 隆雄 UEDA Takao
    • 徳島大学 大学院ソシオテクノサイエンス研究部 THE UNIVERSITY OF TOKUSHIMA, Department of Civil Engineering
    • 亀田 貴文 KAMEDA Takafumi
    • 徳島大学 大学院先端技術科学教育部 THE UNIVERSITY OF TOKUSHIMA, Department of Civil Engineering, Graduate School of Engineering
    • 七澤 章 NANASAWA Akira
    • 電気化学工業株式会社 青海工場無機材料研究センター DENKI KAGAKU KOGYO KABUSHIKI KAISHA, Omi-plant

Abstract

塩害とASRの複合劣化構造物に対して電気化学的防食工法を適用した場合に、コンクリート中の鉄筋近傍に集積するアルカリ金属イオンが、ASRによるコンクリート膨張を促進することが懸念されている。そこで本研究では、ASR膨張抑制効果のあるリチウム塩を含有する複数微細ひび割れ型繊維補強セメント複合材料(HPFRCC)を接着型の陽極システムとして用いることで、鉄筋防食効果とASR膨張抑制効果を併せ持つような新しい電気化学的リハビリテーション手法の可能性について検討を行った。この結果、本工法の適用によって従来の電気化学的防食工法と同程度の鉄筋防食効果が確認されるとともに、電流密度の大きさによらず、HPFRCC陽極層からコンクリート中へのLi<sup>+</sup>の浸透が認められた。

Electrochemical corrosion control methods have been applied to concrete structures deteriorated by steel corrosion in concrete due to chloride attack or carbonation of concrete. However, if such structures contain reactive aggregates that can occur ASR, the application of electrochemical corrosion control method could promote the concrete expansion due to ASR because alkali metallic ions such as Na<sup>+</sup> or K<sup>+</sup> can be drawn toward the steel and accumulated around the steel in concrete. Then it is difficult to determine an effective countermeasure against structures damaged by complex deterioration of chloride attack and ASR.<br/>From these backgrounds, experimental investigation was carried out in order to clarify the possibility of a new electrochemical rehabilitation method using bonded anode layer of the high performance fiber reinforced cementitious composite(HPFRCC)containing lithium salt that has ASR suppression effect. HPFRCC is cementitious material mixed with organic short fibers and can realize the apparent tensile ductility similar with metalic materials. As the results of this study, in addition to the conventional protection effect against steel corrosion, penetration of Li<sup>+</sup> from HPFRCC anode layer to concrete inside was observed. However, adhesive strength between HPFRCC anode layer and concrete surface was reduced due to the electrochemical treatment if HPFRCC contains lithium salt.

Journal

  • Cement Science and Concrete Technology

    Cement Science and Concrete Technology 63(1), 523-529, 2009

    Japan Cement Association

Codes

  • NII Article ID (NAID)
    130004745642
  • Text Lang
    JPN
  • ISSN
    0916-3182
  • Data Source
    J-STAGE 
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