Structural and Mechanical Properties of Doped Tobermorite

As calcium silicate hydrate (C-S-H) is the main binding phase in concrete, understanding doping behavior of impurity elements it important for optimizing structure cementitious materials. However, most current studies focus on cement clinker, and mechanism hydrated not yet fully understood. The component complex, its very similar to that tobermorite mineral family. In this study, effects three different dopants (Mg, Sr Ba) a representing C-S-H—tobermorite—was systematically explored using densify functional theory (DFT) calculations. calculations show Mg leads decrease lattice volume causes obvious coordination changes magnesium–oxygen polyhedra. This may be reason why high formation energy required Mg-doped tobermorite. Meanwhile, only increases Sr- Ba-centered oxygen Specifically, exhibits higher chemical stability shorter interatomic bonding. addition, although distorts structure, stronger bonding between Mg-O atoms also improves compressive (~1.99% average) shear resistance (~2.74% tobermorillonite according elastic modulus has less effect anisotropy Young’s modulus. Our results suggest promising strategy optimized structural design C-S-H.