Crystal structure and hydration characteristics of tricalcium silicate doped with magnesium oxide

The research investigates various methods to identify magnesium oxide influences on the crystal structure and hydration properties of tricalcium silicate. The f-CaO content of the clinkers were analyzed by chemical analysis. The complex disordered superstructure of the tricalcium silicate has been studied by a joint XRD, NMR and TEM. The results show that MgO exerts a remarkable influence on the polymorphisms of C₃S. Mg is not only substitutional atom but also interstitial atom in the crystal lattice of tricalcium silicate. The HRTEM pattern of C3S doped with MgO is covered by the various irregular lattice. The addition of appropriate amount of MgO in raw meal can change the formation kinetic of C₃S, slightly perturb the environment of SiO₄ ^4- tetrahedral, modify the crystal structure of C₃S and affect the hydration activity. Doped with MgO in the raw meal can slow down the hydration rate of alite slightly in early stage.