温度・湿度の変化がC-S-Hの組成および密度に及ぼす影響  [in Japanese] THE INFLUENCE OF TEMPERATURE AND HUMIDITY ON COMPOSITION AND DENSITY OF C-S-H  [in Japanese]

Access this Article

Author(s)

Abstract

本研究では、セメント硬化体中で主要な水和物であるC-S-Hの組成と密度に対して、環境条件である温度や湿度が及ぼす影響について検討を行った。検討を行う際には、C/S比の異なる2種類のC-S-Hを作製し、温度・湿度変化に伴うC-S-Hの水蒸気吸着量と密度の測定を行った。その結果、各湿度における水蒸気吸着量は、C/S比の低い試料ほど多く、同一のC/S比のC-S-Hにおいては、前処理条件の違いによらず高湿度においてH/S比が一致した。また、C-S-Hの密度は、低C/S比のC-S-Hほど各湿度における密度は低い値を示した。さらに、C-S-Hの密度をH/S比を用いて整理した結果、H/S比が3程度のときC-S-Hの密度が最大となり、これらは含水状態の違いによるC-S-Hの構造変化が要因として示唆された。

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.<br/> The purpose of this study is to evaluate the influence of each relative humidity and temperature on the chemical composition and density of C-S-H. The composition(C/S ratio, the H/S ratio) and the density of C-S-H at each relative humidity and temperature were estimated by using synthesized C-S-H. Two C-S-H samples were synthesized. The target C/S ratios were 1.00 and 1.25. Furthermore, the amount of adsorbed water, the density and composition of C-S-H in hardened cement paste also were measured.<br/>From the experimental results, the water content of C-S-H under high relative humidity is same value independent of the drying condition(50℃ or 110℃). When the C/S ratio of synthesized C-S-H decreased, the water content at each relative humidity of C-S-H increased. The density of C-S-H dried at 50℃ was higher than that dried at 110℃. The density of C-S-H was increased by increasing in relative humidity. Furthermore, the density of C-S-H at about RH80% represented the maximum value. From these results, the density of C-S-H was expressed by the H/S ratio independent of the drying condition(50℃ or 110℃). The change of density at each relative humidity was expected to cause the change of the interlayer structure in C-S-H. As with the results of synthesized C-S-H, the density of hardened cement paste changed at each relative humidity. In addition, the density of hardened cement paste at each relative humidity was evaluated by the amount and density of C-S-H in hardened cement paste.

Journal

  • Cement Science and Concrete Technology

    Cement Science and Concrete Technology 67(1), 157-164, 2013

    Japan Cement Association

Codes

  • NII Article ID (NAID)
    130004745754
  • Text Lang
    JPN
  • ISSN
    0916-3182
  • Data Source
    J-STAGE 
Page Top