Abstract Ettringite (AFt) and monosulfoaluminate (AFm(MS)) are the two of the main hydration products of tricalcium aluminate. Ettringite formation is favored in the presence of gypsum, and monosulfoaluminate is the usual AFm phase in a system with low calcium carbonate content. In this article, a new empirical force field, AFFF, is proposed to describe the interactions among species in ettringite, monosulfoaluminate, and tricalcium aluminate at the molecular level. This force field provides structural data and elastic properties that are consistent with experimental and previous simulation results. Using AFFF, the effects of the hydration state of ettringite and monosulfoaluminate on the lattice parameters and elastic constants are studied. Regarding the molecular modeling of the elastic properties of ettringite, simulations with AFFF are considerably less computationally intensive than the other approaches used so far. These results leave room for a better understanding of the nanoscale processes that affect AF-phases behavior in cement systems.

中文翻译：

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钙矾石和单硫铝酸盐的结构和弹性特性的分子模拟

摘要 钙矾石(AFt)和单硫铝酸盐(AFm(MS))是铝酸三钙的两种主要水合产物。在石膏的存在下有利于钙矾石的形成，并且单硫铝酸盐是碳酸钙含量低的系统中常见的 AFm 相。在本文中，提出了一种新的经验力场 AFFF，以在分子水平上描述钙矾石、单硫铝酸盐和铝酸三钙中物种之间的相互作用。该力场提供与实验和先前模拟结果一致的结构数据和弹性特性。使用 AFFF，研究了钙矾石和单硫铝酸盐的水合状态对晶格参数和弹性常数的影响。关于钙矾石弹性特性的分子模型，与目前使用的其他方法相比，使用 AFFF 进行的模拟计算密集程度要低得多。这些结果为更好地理解影响水泥系统中 AF 相行为的纳米级过程留下了空间。