The formation and the properties of the oxide compounds are determined by intrinsic factors (depending on the reactants) and extrinsic ones (the reaction conditions). The formation reactions are defined by a series of thermodynamic functions. In this paper we highlight the correlation between the Gibbs free energy of formation, the reaction energy and the basicity of the reacting oxides, respectively, evaluated through the basicity percentage, pB, in % in the CaO - SiO₂ system.

At the same time, for a series of properties (interaction with water, hydration degree, mechanical resistance to compression, shrinkage) of some mineralogical constituents of the Portland cement clinker it is highlighted their interdependence with basicity.