Defining existence domains in geopolymers through their physicochemical properties

Geopolymeric material is a new type of cement that is synthesized through the alkali activation of aluminosilicates. To improve the properties of the aluminosilicates, the composition is greatly modified. However, through numerous possible synthetic routes to form geopolymers, the determination that the final material has a geopolymer network cannot be ensured, despite the apparent or partial consolidation of material. This work proposes a definition that a domain in the geopolymeric material exists that can be correlated using different techniques to quantify the amount of silicon, potassium and aluminum. Two sources of potassium silicate and various clays with different degrees of amorphous character were compared to determine the importance of the starting materials. The existence domain is an important tool to determine if the synthesized material is a geopolymer network independent of the raw materials used. ► A geopolymer domain is defined by varying initial raw materials on samples. ► Alkali silicate solution constitution is a key point for geopolymerization kinetic. ► The geopolymer material formation depends on the amorphous phase present in clays. ► Infrared observations during formation and good mechanical properties are linked. ► Three materials are defined, a geopolymer, a gel and a partially fused network.