Characterization of Fly Ash dominating ASR suppressing Effects by using SEM-EDS and EBSD
ASR抑制効果を支配するフライアッシュキャラクターのSEM-EDS/EBSDによる解析
Feature analysis of fly ash (FA) was carried out for five different FA (equivalent to JIS Class II) having varied levels of alkali-silica reaction (ASR) suppression effect. The purpose of this study was to identify the chemical and physical characteristics relating ASR suppressing effects. The equipment used was a scanning electron microscope (SEM) combined with, backscattered electron (BSE) detector, energy dispersive X-ray spectrometer (EDS) and electron backscattered diffraction (EBSD). Authors classified FA particles into six phases quantitatively by feature analysis and gave particle size distribution and specific surface area of each phase. The classified particles as mullite dispersed in Si-rich glass matrix showed a strong negative correlation with 14-day expansion of mortar bar evaluated by ASTM C 1260. Judging from the results obtained in this study, specific surface area of Si-rich glass accompanying mullite crystals is revealed to be the key for the ASR suppressing effect of FA. ASR抑制効果の異なるフライアッシュ（FA）（JISⅡ種相当）5種類について，FAの銘柄ごとのキャラクターとASR抑制効果との関係を明らかにすることを目的とし，FAの粒子解析を実施した。後方散乱電子回折（EBSD）とエネルギー分散型X線分光器（EDS）により，FA中の非晶質相の種類と存在状態を把握し，さらに反射電子（BSE）像とEDSを用い粒子解析を行い，FAを構成する相を分類し，各相の体積割合，粒度分布および比表面積を求めた。複数の非晶質相が認められたが，mulliteと非晶質相が混在する粒子の比表面積が大きいものほど，高濃度の外来アルカリ環境下において，高いASR抑制効果を示すことが明らかとなった。ASRを抑制するポゾラン反応は非晶質相によることを考慮すると，上記のFA粒子に含まれる非晶質相がASR抑制効果に大きく寄与していると考えられた。
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- Summary URL:
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Availability:
- Find a library where document is available. Order URL: http://worldcat.org/issn/13404733
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Authors:
- Takahashi, Haruka
- Yamada, Kazuo
- Publication Date: 2012
Language
- English
- Japanese
Media Info
- Media Type: Digital/other
- Features: Figures; Photos; References; Tables;
- Pagination: pp 1-11
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Serial:
- Concrete Research and Technology
- Volume: 23
- Issue Number: 1
- Publisher: Japan Concrete Institute
- ISSN: 1340-4733
- EISSN: 2186-2745
- Serial URL: https://www.jstage.jst.go.jp/browse/crt/-char/en
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Publication flags:
Open Access (libre)
Subject/Index Terms
- TRT Terms: Alkali silica reactions; Backscattering; Electron microscopes; Fly ash; Rock crystals; Spectrometers; X rays
- Subject Areas: Construction; Highways; I50: Construction and Supervision of Construction;
Filing Info
- Accession Number: 01515410
- Record Type: Publication
- Source Agency: Japan Science and Technology Agency (JST)
- Files: TRIS, JSTAGE
- Created Date: Feb 24 2014 8:42AM