高炉スラグ微粉末およびシリカフュームを用いたセメント系硬化体の塩分浸透抵抗性  [in Japanese] CHLORIDE ION PERMEABILITY IN HARDENED CEMENTITIOUS MATERIALS USING GROUND GRANULATED BLAST FURNACE SLAG AND SILICA FUME  [in Japanese]

Access this Article

Author(s)

Abstract

本研究では、普通ポルトランドセメントに対し、高炉スラグ微粉末およびシリカフュームを混和したセメント系硬化体の塩分浸透抵抗性を明らかにするため、塩化物イオン実効拡散係数を求めた。その結果、普通ポルトランドセメントのみを用いた配合と比較して、高炉スラグ微粉末とシリカフュームを併用した配合の塩化物イオン実効拡散係数は大きく低下した。塩化物イオン実効拡散係数の低下は、硬化体の空隙率だけでは説明できず、シリカフュームの混和によって空隙構造の屈曲度が増加したことも原因であると考えられた。また、屈曲度の増加は、水和物の大部分を占めるC-S-HのC/S比が低下し、C-S-Hの比表面積が増加したことが原因であることを明らかにした。

The purpose of this study is to clarify the diffusivity of chloride ion in hardened cementitious materials using both ground granulated blast furnace slag and silica fume.<br/>In this study, the effective diffusion coefficients of chloride ion, the oxygen diffusion coefficients, the porosity, the pore size distribution and the kinds and amounts of hydration products were measured. From the experimental result, the effective diffusion coefficients of chloride ion were considerably reduced by using ground granulated blast furnace slag and silica fume. It is studied the reason why the use of silica fume caused a decrease in the effective diffusion coefficients of chloride ion. The effective diffusion coefficients of chloride ion could not be evaluated only by the porosity. However, there was a correlation between oxygen diffusion coefficients and effective diffusion coefficients of chloride ion. Tortuosity, which was an index expressing oxygen diffusion path length affected by the microstructure, was calculated. The tortuosity was increased by use of silica fume.<br/>It has been reported by previous research that the tortuosity can be evaluated by the specific surface area of C-S-H regardless of type of binder. The specific surface area of C-S-H was affected by the C/S ratio of C-S-H which is a major part of hydration products. In this study, the tortuosity of hardened cementitious materials using both ground granulated blast furnace slag and silica fume was evaluated by the specific surface area of C-S-H. Therefore, the reduction of the effective diffusion coefficients of chloride ion by using silica fume was caused by the increase of the specific surface area of C-S-H.

Journal

  • Cement Science and Concrete Technology

    Cement Science and Concrete Technology 66(1), 452-459, 2012

    Japan Cement Association

Codes

  • NII Article ID (NAID)
    130004574732
  • Text Lang
    JPN
  • ISSN
    0916-3182
  • Data Source
    J-STAGE 
Page Top