セメント系硬化体の水和物の水蒸気吸着等温線に関する研究  [in Japanese] STUDY ON WATER VAPOR ADSORPTION ISOTHERMS OF HYDRATION PRODUCTS IN HARDENED CEMENT PASTE  [in Japanese]

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Abstract

本研究では、セメント系硬化体の水蒸気吸着量を評価するため、各種水和物およびセメント硬化体の相対湿度0%~97%の範囲の水蒸気吸着量について検討を行った。その結果、合成C-S-Hおよび合成エーライトから水和生成したC-S-Hは、任意の湿度環境下においてCaO/SiO<sub>2</sub>モル比とH<sub>2</sub>O/SiO<sub>2</sub>モル比が直線関係となることを明らかにし、C-S-Hの水蒸気吸着量をその組成に基づいて推定する式を提案した。また、C-S-H以外の水和物であるカルシウムアルミネート水和物の水蒸気吸着量を測定し、C-S-Hの水蒸気吸着量の推定式およびC-S-H以外の水和物の水蒸気吸着量を用いて、セメントペーストの相組成より硬化体全体の水蒸気吸着量を推定した。

The performances of concrete are influenced by the microstructure of hardened cement paste. The microstructure of hardened cement paste is affected by the hydration products. Therefore, in order to evaluate the characteristics of the microstructure of hardened cement paste, the physical properties of hydration product should be clarified accuracy.The purpose of this study is to evaluate the amount of adsorbed water in cement paste. The composition(C/S ratio, the H/S ratio)and the amount of adsorbed water of C-S-H were estimated by using synthesized C-S-H and C-S-H generated from synthesized alite paste. In addition, the amount of adsorbed water of calcium hydroxide and calcium aluminate hydrates were estimated by using synthesized hydration products. Furthermore, the amount of adsorbed water of hardened cement paste also was measured.From the experimental results, the H/S ratio of C-S-H under each relative humidity is proportional to the C/S ratio independent of the mix proportion and curing temperature. From these results, the relation equation between the C/S ratio and the amount of adsorbed water of C-S-H was proposed. The amount of adsorbed water calculated from the relation equation of C-S-H is good agreement with the amount of adsorbed water of the synthesized C-S-H. In addition, the amount of adsorbed water of calcium aluminate hydrates, such as ettringite, monosulfate and C<sub>4</sub>AH<sub>13</sub> were higher than that of calcium hydroxide and hydrogarnet. Moreover, the amount of adsorbed water of hardened cement pastes can be calculated from the amount of hydration products and each amount adsorbed water of hydration products.

Journal

  • Cement Science and Concrete Technology

    Cement Science and Concrete Technology 66(1), 167-174, 2012

    Japan Cement Association

Codes

  • NII Article ID (NAID)
    130004574688
  • Text Lang
    JPN
  • ISSN
    0916-3182
  • Data Source
    J-STAGE 
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