The alkaline activation of the aluminosilicates (geopolymer production) in industrial by-products such as fly ash or blast furnace slag is a consolidated methodology that has driven the development of binders with features equalling or improving on the characteristics of ordinary portland cement.The nature of the main reaction products, i.e., gels with varying composition and properties (C-A-S-H, N-A-S-H or (N,C)-A-S-H), depends on a number of factors, including the chemical composition of the raw material used, especially its CaO content.A model for alkaline activation has recently been designed to develop new cementitious systems known as hybrid alkaline cements.These multi-component systems contain a high percentage of mineral additions (fly ash,metakaolin, slag), low proportions (<30 %) of portland clinker and moderately alkaline solid activators.