カルシウムアルミネート系水和物を考慮したセメント硬化体の比表面積の推定方法に関する基礎的研究  [in Japanese] FUNDMENTAL STADY ON THE ESTIMATION METHOD OF THE SPESIFIC SURFACE AREA OF HARDENED CEMENT PASTE CONSIDERING CALCIUM ALUMINATE HYDRATES  [in Japanese]

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Abstract

本研究ではカルシウムアルミネート系水和物を考慮したセメント硬化体の比表面積の推定方法の検討を目的とし、合成アルミネート相を用いて水和反応の検討を行い、カルシウムアルミネート系水和物の影響を考慮したセメント硬化体全体の比表面積の推定を行った。その結果、C<sub>3</sub>AH<sub>6</sub>生成量とアルミネート相の反応率には水結合材比によらず一定の関係があることがわかった。また、セメント硬化体中のカルシウムアルミネート系水和物の比表面積の推定では、アルミネート相の反応率とC<sub>3</sub>AH<sub>6</sub>生成量のみを把握すればよいことを明らかにし、各水和物を定量した場合と同等の精度でセメント硬化体全体の比表面積を推定することが可能となった。

The specific surface area, which is a micro-structure of hydration products, is an important physical property of concrete. It has been clarified that the specific surface area affects mass transferred, adsorption of ions in hardened cement paste and shrinkage of hardened cement paste. These phenomena affect concrete durability. Therefore, the specific surface area of concrete should be estimated accurately in order to estimate the concrete performance.<br/>It was clarified that C-S-H affected the specific surface area of hardened cement paste. However, the specific surface area can not be estimated only by the specific surface area of C-S-H, and it is needed to consider the specific surface area of calcium aluminate hydrates.<br/>The purpose of this study is to clarify the estimation method of the specific surface area of hardened cement paste considering calcium aluminate hydrates. From the experimental results, the relationship between the reaction ratio of C<sub>3</sub>A and the amount of C<sub>3</sub>AH<sub>6</sub> can be formulated independent of water-binder ratio. Moreover, the specific surface area of calcium aluminate hydrates in hardened cement paste can be estimated by using only the reaction ratio of C<sub>3</sub>A and the amount of C<sub>3</sub>AH<sub>6</sub>. The total amount of AFt, AFm and C<sub>4</sub>AH<sub>13</sub> can be calculated from the reaction ratio of C<sub>3</sub>A and the amount of C<sub>3</sub>AH<sub>6</sub>. The specific surface area of C<sub>3</sub>AH<sub>6</sub> is too small in comparison of those of AFt, AFm and C<sub>4</sub>AH<sub>13</sub>. Therefore, the specific surface area of C<sub>3</sub>AH<sub>6</sub> can be negligible when estimating the specific surface area of hardened cement paste. The total specific surface area of calcium aluminate hydrates can be estimated from the total amount of AFt, AFm and C<sub>4</sub>AH<sub>13</sub> without determining amount of each three hydration products can not be estimated quantitatively.

Journal

  • Cement Science and Concrete Technology

    Cement Science and Concrete Technology 66(1), 197-204, 2012

    Japan Cement Association

Codes

  • NII Article ID (NAID)
    130004574692
  • Text Lang
    JPN
  • ISSN
    0916-3182
  • Data Source
    J-STAGE 
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