著者

谷口 円 桂 修 佐川 孝広 濱 幸雄

出版者

日本建築学会

雑誌

日本建築学会構造系論文集 (ISSN:13404202)

巻号頁・発行日

vol.76, no.668, pp.1745-1753, 2011-10-30 (Released:2012-01-25)

参考文献数

22

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The aim of this research is to propose a method to predict the strength development of concrete using equivalent age. The experiment of strength development was carried out. Ordinary Portland cement, moderate-heat Portland cement and low-heat Portland cement were used for concrete specimen. Water cement ratio was ranged from 0.3 to 0.6. Strength development of concrete cured below subzero temperature was examined too. The result showed that the apparent activation energy in equivalent age equation depends on mineral composition of cement. Furthermore, the effect of freezing on the reaction rate of strength development was shown. Consequently, the strength development of concrete can be estimated from mineral composition of cement, nominal strength of concrete and curing temperature by the method proposed in this paper.

著者

佐川 孝広 濱 幸雄 塚本 康誉

出版者

一般社団法人 セメント協会

雑誌

セメント・コンクリート論文集 (ISSN:09163182)

巻号頁・発行日

vol.68, no.1, pp.239-245, 2015-03-31 (Released:2015-03-27)

参考文献数

27

被引用文献数

1 2

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本研究では現在JIS規格はあるがほとんど生産されていない高炉セメントA種に着目し、高炉セメントA種の強度発現と水和反応に及ぼす無水石こうや石灰石微粉末の影響について検討した。水和反応の評価にはX線回折/リートベルト解析の外部標準法を用いた。その結果、高炉スラグ微粉末の混合量が20%の高炉セメントA種を用いたモルタル圧縮強度は、初期材齢で普通ポルトランドセメント(OPC)の75%程度、材齢91日までにOPCと同等となった。無水石こうや石灰石微粉末の混和による圧縮強度の変化は、水和反応解析により求めたセメントや高炉スラグ微粉末の反応率、水和生成物量、空隙量の変化でよく説明できた。

著者

平島 剛 保坂 文教 本多 覚 恒川 昌美 伊藤 正澄 佐川 孝広

出版者

The Mining and Materials Processing Institute of Japan

雑誌

資源と素材 : 資源・素材学会誌 : journal of the Mining and Materials Processing Institute of Japan (ISSN:09161740)

巻号頁・発行日

vol.119, no.9, pp.553-558, 2003-09-25

被引用文献数

2 2

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Fine waste concrete smaller than 5mm obtained from a recycling plant of waste concrete was used as feed and ground by a wet attrition mill. Recovery of the fine aggregate and cement hydrate powder from the ground fine waste concrete was investigated using a laboratory / pilot scale Mozley multi-gravity separator (MGS). The water absorption of the fine aggregate obtained as the high specific gravity product was less than 3.5 % and the dry density was larger than 2.4 g/cm³. The powder obtained as low specific gravity product contained about 29 % of fine aggregate. The reference for normal clinker and the mixture prepared by mixing the reference materials with 38 wt% of the powder were heated at 1,500 °C, with the hydraulic modulus adjusted to 2.18, the silica modulus to 2.8, and the iron modulus to 1.64. The phases of the clinker were identified and quantitatively determined by a microscopic point-count procedure and by the Rietveld analysis using XRD data. There was good agreement in the clinker minerals of the reference and the mixture clinkers. These results show that the fine aggregate and cement hydrate powder recovered from fine waste concrete by MGS can be recycled in cement and concrete production.