A DISCUSSION BASED ON EPMA ANALYSIS ON THE TREATMENT FOR VERTICAL PLACING JOINT OF CONCRETE

EPMA分析に基づくコンクリートの鉛直打継ぎの界面処理に関する考察

The enhancement of structural performance of placing joint in concrete is one of the most critical issues for concrete structure in terms of interfacial bonding strength and toughness. There are well-known purposes of surface treatment, such as a removal of the weak layer and a roughening of the surface for the better adhesion. The authors re-investigated whether or not there are any other reasons in an attempt to achieving high structural performance for the joint. The authors conducted fracture toughness test with concrete specimens including observations of the placing joint with Electron Probe Microscope Analyzer (EPMA). The observations made it clear that there is another important reason of making the rough surface, which is the dispersion of the weak layer generated by bleeding from the concrete placed afterwards along the substrate concrete. The authors proposed new methods of image-analysis；one is observing a weak layer by emphasizing the quantity of Ca and another is revealing a wall effect of aggregate by accumulating the quantity of Si near the interface. These two methods not only helped reveal the mechanisms of formation of the weak layer but also helped determine quantitatively the minimum depth of roughening the surface for the vertical placing joint.コンクリート構造物に生じる打継ぎ界面では、付着性能（強度と靱性）を向上させることが重要な課題である。本研究では、その付着性能向上に向けた検討を深めるために、界面の処理目的として周知の脆弱層除去と凹凸による嵌合強化以外にはないのか、改めて検討した。打継ぎ界面近傍のElectron Probe Microscope Analyzer (EPMA)観察と破壊靱性試験を行った結果、先打ち部の界面処理による凹凸は、嵌合の強化と同時に後打ちで生じる脆弱層の分散にも寄与して、付着性能向上に役立つことを明らかにした。また脆弱層の観察手法に関する新たな提案を行うと共にそれを用いて脆弱層の形成機構の考察を行った。さらに界面における付着性能を得るために必要な目荒し深さの定量的な根拠を示した。

• Record URL:
  • https://doi.org/10.14250/cement.66.251
• Record URL:
  • https://www.jstage.jst.go.jp/article/cement/66/1/66_251/_pdf
• 
• Summary URL:
  • http://scholar.google.com/scholar_lookup?title=A+DISCUSSION+BASED+ON+EPMA+ANALYSIS+ON+THE+TREATMENT+FOR+VERTICAL+PLACING+JOINT+OF+CONCRETE&author=A.+SATOH&author=S.+ISHIYAMA&author=K.+YAMADA&publication_year=2012
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/09163182
• Authors:
  • SATOH, Ayumi
  • ISHIYAMA, Satoru
  • YAMADA, Kanji
• Publication Date: 2012

Language

• English
• Japanese

Media Info

• Media Type: Digital/other
• Features: Figures; Photos; References; Tables;
• Pagination: pp 251-258
• Serial:
  • Cement Science and Concrete Technology
  • Volume: 66
  • Issue Number: 1
  • Publisher: Japan Cement Association
  • ISSN: 0916-3182
  • EISSN: 2187-3313
  • Serial URL: https://www.jstage.jst.go.jp/browse/cement/-char/en
• Publication flags:

  Open Access (libre)

Subject/Index Terms

• TRT Terms: Calcium hydroxide; Concrete structures; Fracture properties; Image analysis; Joints; Roughness; Toughness; Wall effect
• Subject Areas: Bridges and other structures; Highways; Materials; I24: Design of Bridges and Retaining Walls;

Filing Info

• Accession Number: 01522844
• Record Type: Publication
• Source Agency: Japan Science and Technology Agency (JST)
• Files: TRIS, JSTAGE
• Created Date: Apr 24 2014 11:44AM