The paper presents the results of the investigations regarding the obtaining and characterisation of cementitious materials in which the Portland cement clinker is replaced with additions of limestone, or blast furnace slag and fly ash, which entail a series of benefits such as: optimising the strength, decreasing the CO₂ emissions and reducing the production costs. The paper brings genuine information regarding the optimisation of the formulation and the manufacturing process of the cements with addition of limestone or limestone and fly ash.