A molecular dynamics study of cementitious calcium silicate hydrate (C-S-H) gels

Abstract

In this article we study the polymerization of silicic acids (Si(OH)₄) in the presence of calcium ions by molecular dynamics simulations. We focus on the formation and structure of cementitious calcium silicate hydrate (C-S-H) gels. Our simulations confirm that, in accordance with experiments, a larger content of calcium ions slows down the polymerization of the cementitious silicate chains and prevents them from forming rings and three-dimensional structures. Furthermore, by an analysis of the connectivity of our simulated silicate chains and by a count of the number of formed Ca-OH and Si-OH bonds, the relationship with commonly employed structural models of calcium silicate hydrate (C-S-H) gels, such as 1.4-nm tobermorite and jennite, is discussed.