APPLICATION OF NEW QUANTIFICATION METHOD OF HYDRATED MONOMER TO HYDRATION OF SILICATE MINERALS

Autor: Kazuto Kurosawa, Toyoharu Nawa, Tomotaka Awamura, Daisuke Minato
Rok vydání: 2012
Předmět:
Zdroj: Cement Science and Concrete Technology. 66:47-54
ISSN: 2187-3313
0916-3182
DOI: 10.14250/cement.66.47
Popis: It is known from the data of the reaction of tricalcium silicate that it reacts with water in two steps; In the first step, it is dissolved by proton attacking from water and forms an intermediate phase which is converted in the second step into calcium silicate hydrate (C-S-H) as the final product. The intermediate phase has been detected by the difference in the data from ¹H-²⁹Si CP MAS-NMR and ²⁹Si MAS-NMR, but this method is complicated and expends a lot of time for measurement. This paper describes a new method for quantifying of hydrated monomer of silicate anion (HM) as intermediate phase, which can be quantified in a short time by the difference between the amount of dissolved silicate and the amount of silicate anion more than dimer. The amount of dissolved silicate is determined by X-Ray Diffraction / Rietveld analysis, while the amount of silicate anion more than dimer is determined by ²⁹Si MAS-NMR. Comparison of the amount of HM detected by ¹H-²⁹Si CP MAS-NMR and ²⁹Si MAS-NMR demonstrated that our method was suitable to quantify HM. Our method was applied for determining the quantity of HM during hydration process of tricalcium silicate, dicalcium silicate, and the mixture of tricalcium silicate and dicalcium silicate to make clear the mechanism on forming C-S-H. The results obtained in this study indicated that the contribution of HM to the formation of C-S-H was different depending on the kind of calcium silicate. Further, the comparison with the simple substances hydrating, it could be confirmed that the effect of HM on the formation C-S-H was complicated and different from that during hydration of the mixture of tricalcium silicate and dicalcium silicate.本研究では初めに、既報により提案したhydrated monomer（HM）定量に関する新手法¹の定量性を検証した。¹H-²⁹Si CP MAS-NMRを用いて算出したHM量と新手法により算出したHM量は、C₃Sの材齢7日、28日試料においてよい一致を示した。次に新手法を用いてC₃SおよびC₂S、C₃S＋C₂S混合物の水和反応におけるHM、C-S-Hを定量した。その結果、水和初期において鉱物は溶解してただちにC-S-Hを生成せずにHMとして存在することが確認された。また、シリケート鉱物の種類が異なると、鉱物の溶解率に対するC-S-Hの生成挙動も異なることが示唆された。さらにC₂Sにおいて、C₃S＋C₂S混合物の水和反応ではC₂S単体の水和反応と異なるC-S-H生成過程が認められた。
Databáze: OpenAIRE
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