Kuzielová Eva, Slaný Michal, Žemlička Matúš, Másilko Jiří, Palou Martin Tchingnabé
Institute of Construction and Architecture, Slovak Academy of Sciences, Dúbravská Cesta 9, SK-845 03 Bratislava, Slovakia.
Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, SK-812 37 Bratislava, Slovakia.
Materials (Basel). 2021 May 24;14(11):2786. doi: 10.3390/ma14112786.
Two substitution levels of Portland cement by silica fume (SF; 30 and 50 mass%) and three hydrothermal treatment regimes (0.5, 1.2, and 2 MPa and 165, 195, and 220 °C for 7 days, respectively) were selected for the investigation of high-temperature phase formation. A combination of thermogravimetric, X-ray diffraction, and Fourier transform infrared analyses in the mid-IR region was used to overcome the shortcomings of individual techniques for the identification of these complex systems. Changes in molecular water amounts, the polymerization degree of silicate chains, or their decomposition due to transformations and crystallization of phases at hydrothermal conditions were observed and discussed concerning composition. Contrary to the calciochondrite, hydrogrossular phases, α-CSH, and jaffeite detected in the systems without SF, a decrease in CaO/SiO ratio resulted in the formation of stable tobermorite in the case of 30 mass% SF, whilst calcium hydrogen silicate, gyrolite, and cowlesite were identified as more thermally stable phases in the samples with 50 mass% SF.
选择硅灰（SF；30质量%和50质量%）对波特兰水泥进行两种替代水平，并选择三种水热处理制度（分别为0.5、1.2和2 MPa以及165、195和220℃，持续7天）来研究高温相形成。采用热重分析、X射线衍射和中红外区域的傅里叶变换红外分析相结合的方法，以克服单独技术在识别这些复杂体系方面的缺点。观察并讨论了水热条件下分子水量的变化、硅酸盐链的聚合度或由于相的转变和结晶导致的分解，并涉及组成。与不含SF的体系中检测到的钙铝榴石、水钙铝榴石相、α-CSH和贾菲石相反，在30质量% SF的情况下，CaO/SiO比的降低导致形成了稳定的雪硅钙石，而在50质量% SF的样品中，硅酸氢钙、柱沸石和考利石被确定为更热稳定的相。
