Gypsum & Lime
Online ISSN : 2185-4351
ISSN-L : 0559-331X
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Volume 1972, Issue 117
Displaying 1-8 of 8 articles from this issue
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  • Study on Rapid-Hardening Cement
    Masafumi SUGANO, Toshiji IKEJIMA, Junichi KASAI
    1972 Volume 1972 Issue 117 Pages 40-64
    Published: March 01, 1972
    Released on J-STAGE: March 07, 2011
    DOIhttps://doi.org/10.11451/mukimate1953.1972.40
    JOURNAL FREE ACCESS
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    Study on trial manufacture of the rapid hardening cement has been done for water leakage proof construction work, and it is being used for practical purpose to some extent today. So called blended cement, the aluminous cement-lime system or aluminous cement-Portland cement-lime system is known to be flush setting, and it is also known that about 1% of the setting retarder which forms coordination compounds with Ca2+ is effective in terms of hardening time. This retarder however is expensive and an effort was done to find inexpensive one. This report introduces the results of several experiments on that point. That is, some sulfate compounds instead of the above mentioned retarder were examined in the laboratory.
    The previous study revealed that at least 20% of lime was necessary in the systems and the authors used the same mixture content cement as the base, then added several kinds of sulfate compounds on them. The results are summarized as follows.
    Two-five minutes setting time was obtained by adding copper, zinc, and lead sulfates. More rapid setting within a minute was obtained in the case of sodium and magnesium sulfates. From the view point on strength, copper sulfate showed the best result in the aluminous cement-Portland cement-lime system.Compressive strength tended 100-150 kg/cm2 at the measurement of one hour after water adding.
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  • Properties of Cement, Consisting of 2CaO·SiO2 and CaO·Al2O3
    Masamitsu YANAGI, Masashi SAITO
    1972 Volume 1972 Issue 117 Pages 43-47
    Published: March 01, 1972
    Released on J-STAGE: March 07, 2011
    DOIhttps://doi.org/10.11451/mukimate1953.1972.43
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    There has been already reported the alumino-belite cement, consisting of 2CaO·SiO2 and CaO·Al2O3, which showed a significant strength increase during the later period, which contained fairly large amount of β-C2S.
    We have studied this kind of cement, especially from the view point of expansive cement, such as M Type of expansive cement, a mixture of Portland cement, calcium aluminate cement and calcium sulfate.
    For the purpose of making this kind of clinker, it is necessary for making the raw mixtures burned at lower temperature than the formation of gehlenite. In such case the small amount of BaO showed effectable result to protect the dusting of dicalcium silicate.
    When those clinker was hydrated, there showed CAH10 and C2AH8 and at later age formed C2ASH8, and by adding calcium sulfate, formed C3ACaSO412H2O and C3A3CaSO432H2O.
    We tested the expansibility of the cement, which contained varying proportion of the finely crushed clinker and calcium sulfate. When the amount of calcium sulfate is suitable for making ettringite, the rate of expansion became slower but volume increase became larger than the less amount of calcium sulfate.
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  • Manufactures of CaS2O3 and Mg (OH) 2 as a Use of SO2 from Exhaust Gases and of S from Heavy Oils
    Keiichi MURAKAMI, Hirobumi TANAKA, Osamu SATO
    1972 Volume 1972 Issue 117 Pages 48-53
    Published: March 01, 1972
    Released on J-STAGE: March 07, 2011
    DOIhttps://doi.org/10.11451/mukimate1953.1972.48
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    Calcium thiosulfate, shown in a previous paper, is available as an accelerator on the hydration of portland cement. The compound is made by using SO2 and S as raw materials. Therefore, manufacture of CaS2O3 can be applied as a use of SO2 from exhaust gases and of S from heavy oils.
    In present paper, a foregoing studies for making CaS2O3 are reviewed and new methods are examined A reasonable method of a foregoing studies is that through the reaction between CaSO3 and S. The reaction, however, in which a reciprocal reaction predominates with increasing reaction temperature.
    The formation of MgS2O3 by the reaction between MgSO3 and S is accelerated with increasing reaction temperature. As Mg++ in MgS2O3 easily replaced by Ca++, a concentrated solution of CaS2O3 and Mg (OH) 2 are simultaneouly produced, by adding slaked lime milk or slaked dolomite milk to concentrated solution of MgS2O3.
    Besides, calcium thiosulfate is supposed to use not only as an accelerator on the hydration of portland cement, but also as an agent in drifting process of natural pulp and as an insecticide of limesulfure system. Magnesium hydroxide is an important raw material for refractories.
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  • Studies on the Hardened Pastes of Portland Cement - Calcined Gypsum Mixtures
    Hidetoshi AKIMOTO, Hirobumi TANAKA, Keiichi MURAKAMI
    1972 Volume 1972 Issue 117 Pages 54-59
    Published: March 01, 1972
    Released on J-STAGE: March 07, 2011
    DOIhttps://doi.org/10.11451/mukimate1953.1972.54
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    Strength and hydration products of hardened pastes consisted of ordinary portland cement-calcined gypsum mixtures were investigated by strength tests, X-ray diffraction analysis, differential thermal analysis, and electoron microscopic observation.
    The results are summerized as follows :
    (1) The hydration of calcined gypsum was accelerated with increasing cement content, but the strength of hardened paste was relatively low in initial stage.
    (2) As cement content increases, the strength of hardened paste was developed with increasing curingperiod. The developement of strength would be suggested due to the extremely dense structure of the hardened body in which interspaces was filled with a considerable amount of ettringite and calcium silicate hydrates.
    (3) Ettringite was slightly electron microscopic-visible in very early stage, but increased after long period.
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  • [title in Japanese]
    Koichi FUKURO
    1972 Volume 1972 Issue 117 Pages 65-71
    Published: March 01, 1972
    Released on J-STAGE: March 07, 2011
    DOIhttps://doi.org/10.11451/mukimate1953.1972.65
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  • [title in Japanese]
    [in Japanese]
    1972 Volume 1972 Issue 117 Pages 72
    Published: March 01, 1972
    Released on J-STAGE: March 07, 2011
    DOIhttps://doi.org/10.11451/mukimate1953.1972.72
    JOURNAL FREE ACCESS
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  • [title in Japanese]
    Junpei OKA, [in Japanese]
    1972 Volume 1972 Issue 117 Pages 72a-77
    Published: March 01, 1972
    Released on J-STAGE: March 07, 2011
    DOIhttps://doi.org/10.11451/mukimate1953.1972.72a
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  • [title in Japanese]
    Osao SAKAEDA, Masamichi FUJIHARA
    1972 Volume 1972 Issue 117 Pages 78-82
    Published: March 01, 1972
    Released on J-STAGE: March 07, 2011
    DOIhttps://doi.org/10.11451/mukimate1953.1972.78
    JOURNAL FREE ACCESS
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