Alkali-activated aluminosilicates (geopolymers) have been considered applicable substituent to ordinary Portland cement due to high performance and preferentially to reduced consumption of CaO, consequently reduced CO2 emission.During geopolymer formation silicate and aluminate species assume tetrahedral in which aluminum is negatively charged but it is balanced by cations present in alkaline solution.However, in contact with water alkali-activated aluminosilicates can release these cations thus diminishing mechanical strength, for example.Phosphate species can be inserted in geopolymer structure due to their condensation capability improving mechanical properties and in this case phosphates assume positive charge neutralizing negative aluminum species.In this work we focus in acidic activation of aluminosilicates using phosphoric acid and environmental changing around species of Si, Al and P.Aluminosilicate (Al2O3-2SiO2) synthesized by sol-gel method, with Al/Si ratio close to 1, was mixed with phosphoric acid and then a stiffed solid was obtained with Al∶Si∶P ratio =1∶1∶1, respectively.