Highly Reactive β-Dicalcium Silicate: II, Hydration Behavior at 25°C Followed by 29Si Nuclear Magnetic Resonance

Authors

  • Hideki Ishida,

    1. Ceramics Research Laboratory, Nagoya Institute of Technology, Tajimi, Gifu, 507 Japan, Ceramics Research and Development Division, INAX Corporation, Tokoname, Aichi, 479 Japan, Construction Materials Research Laboratory, Onoda Cement Company, Ltd., Tokyo, 135 Japan
    Search for more papers by this author
    • Member, American Ceramic Society.

    • *

      Nagoya Institute of Technology.

    • INAX Corporation.

  • Yoshihiko Okada,

    1. Ceramics Research Laboratory, Nagoya Institute of Technology, Tajimi, Gifu, 507 Japan, Ceramics Research and Development Division, INAX Corporation, Tokoname, Aichi, 479 Japan, Construction Materials Research Laboratory, Onoda Cement Company, Ltd., Tokyo, 135 Japan
    Search for more papers by this author
    • Member, American Ceramic Society.

    • Onoda Cement Company, Ltd.

  • Takeshi Mitsuda

    1. Ceramics Research Laboratory, Nagoya Institute of Technology, Tajimi, Gifu, 507 Japan, Ceramics Research and Development Division, INAX Corporation, Tokoname, Aichi, 479 Japan, Construction Materials Research Laboratory, Onoda Cement Company, Ltd., Tokyo, 135 Japan
    Search for more papers by this author
    • Member, American Ceramic Society.

    • *

      Nagoya Institute of Technology.


  • M. Grutzeck—contributing editor

  • T. Mitsuda was supported by a research fellowship by the Cement Association of Japan.

Abstract

The hydration behavior at 25°C of highly reactive β-dicalcium silicate synthesized from hillebrandite (Ca2(SiO3)(OH)2) was studied over a period of 7 to 224 d using 29Si magic-angle spinning nuclear magnetic resonance (MAS NMR). The hydration product, C-S-H, contains Q2 and Q1 silicate tetrahedra, the chemical shifts of which are independent of the water/solid (w/s) ratio and curing time. Until the reaction is completed, the amounts of Q1 and Q2 formed are independent of the w/s ratio, being determined only by the degree of reaction. The ratio Q2/Q1 increases as the reaction progresses and as the curing time becomes longer. From the values of Q2/Q1, it appears that the hydrate is a mixture of dimers and short single-chain polymers. The Ca/Si ratio of the hydrate is high, taking values close to 2.0, but the Ca/Si ratio does not influence the Q2/Q1 ratio. It was also found that the NMR peak intensities allow quantitative assessment similar to XRD.

Ancillary