硅酸盐学报

硫铝酸钙-二水石膏-氢氧化钙-水水化系统的热力学计算

作者：张洋洋常钧赵九野

关键词：钙矾石氢氧化铝相自由能焓定量分析

分类号：

出版年,卷(期):页码：2017,45(5):6-6

DOI：10.14062/j.issn.0454-5648.2017.05.00

摘要：

硫铝酸钙(C4A3$)是硫铝酸盐水泥熟料中最重要的组成部分。既有研究表明，调整C4A3$、二水石膏(C$H2)和氢氧化钙(CH)的比例可以改变水化产物中钙矾石(AFt)和AH3相的比例，但缺乏从热力学计算和实验方面的验证。使用Gibbs自由能变和焓变对水化反应进行计算，结果表明：反应在热力学上可自发进行，并且反应为放热反应，有利于反应自发进行；将实验室烧成的C4A3$复配确定比例的C$H2、CH，在水灰比为10的情况下水化28 d，使用X射线衍射和热重分析对水化产物定量分析，结果表明水化产物中只有AFt和AH3，虽然实验值与理论计算值不能完全吻合，但随着C$H2、CH掺量的增加，水化产物中AFt的含量逐渐增多，而AH3相的含量逐渐减少。

Calcium sulfoaluminate (i.e., C4A3$) is a dominant mineral in calcium sulfoaluminate cement. The previous studies indicated that the radio of C4A3$、gypsum (i.e., C$H2) and calcium hydroxide (i.e., CH) could determine the ettringite (i.e., AFt) to AH3 ratios in the final product. However, little work on the corresponding thermodynamic calculation and experimental validation has been reported. In this paper, the changes of the Gibbs free energy and enthalpy were used for the thermodynamic calculation of hydration reaction. The reaction can occur spontaneously in the thermodynamics, and the reaction is an exothermic reaction, thus favoring the spontaneous reaction. The synthesized C4A3$ is incorporated with the specific quantities of C$H2 and CH, hydrated for 28 d with distilled water at a w/c ratio of 10. According to the quantitative phase analysis by X-ray diffraction and thermogravimetry, there exist only AFt and AH3 phases in the hydration products. Although the AFt and AH3 contents are not consistent with the theoretical values, the AFt content increases and AH3 content reduces with the increase of the C$H2 and CH contents.

基金项目：

国家自然科学基金(51472041)。

作者简介：

张洋洋(1991—)，男，博士研究生。

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