Studies on Commercial Dolomite Plasters

DOI

Bibliographic Information

Other Title
  • 市販ドロマイトプラスターに関する研究

Description

We studied the qualities of several sorts of commercial dolomite plasters. Results summarized are as follows : -<BR>1) Chemical composition of dolomite plasters is in the range of SiO2 0.5-15.9 %, CaO 42.7-52.2 % and MgO 16.5-25.4 %.<BR>2) Thermo-balance test showed that dolomite plasters consisted of Mg (OH) 2, Ca (OH) 2, CaCO3 and MgO, and those decomposition temperature lied at 300 to 450°C for Mg (OH) 2, 450 to 550°C for Ca (OH) 2 and 700 to 900°C for CaCO3.<BR>3) MgO calcined at low temperature hydrates quickly in water but in air its hydration proceeds very slowly even in high humidity.<BR>4) Relative weight percentage between MgO and Mg (OH) 2 in samples change widely, the latter from 30 to 80.5) X-ray test showed that samples contained Mg (OH) 2, Ca (OH) 2 and CaCO3, and all CaO changed to Ca (OH) 2 perfectly by hydrating. Samyles had poor MgO were rich in CaCO3. The reason is considered to be the mixed-existing of half-decomposed dolomite in the form of MgO-CaCO3. The hardening products after one month consisted of CaCO3, Ca (OH) 2 and Mg (OH) 2, and unhydrated CaO and MgO could not be found.<BR>6) Dolomite plasters rich in MgO·CaCO3 are high at compressive and tensile strength, while they rich in Mg (OH) 2 are low.<BR>7) Coefficients of viscosity and hardness are almost little in difference and difficult to compare.

Journal

  • Gypsum & Lime

    Gypsum & Lime 1956 (21), 1126-1132, 1956

    The Society of Inorganic Materials, Japan

Details 詳細情報について

  • CRID
    1390282680364941184
  • NII Article ID
    130004010670
  • DOI
    10.11451/mukimate1953.1956.1126
  • ISSN
    21854351
  • Data Source
    • JaLC
    • CiNii Articles
  • Abstract License Flag
    Disallowed

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