EFFECT OF SI/K RATIO ALKALINE SOLUTIONS ON MECHANICAL PROPERTIES OF GEOMATERIAL COMPOUNDS

摘要

Geopolymer materials are obtained by the alkaline activation of aluminosilicate sources, the best of which is metakaolin. Alkaline activation could be accomplished with potassium silicate solution synthesized by dissolution of silica. The aim of this work is to study the role play by the siliceous species within the activating solution in the presence of metakaolin on the structure and the mechanical properties of geopolymer-type materials. To do this, the influence of the Si/K molar ratio on (ⅰ) the nature of the species present in alkaline solution and (ⅱ) on the structure of synthesized materials was investigated by ~(29)Si NMR spectroscopy. Structure and reactivity variations in solutions were revealed according to the Si/K molar ratio. The synthesis of geopolymers highlighted the influence of the Si/K ratio on the structure and mechanical properties of geopolymer-type materials.