Structure and properties of new eco-material obtained by phosphoric acid attack of natural Tunisian clay

The mechanical strength of geopolymers is maximum when Si/P molar ratio, equal to 2.25, which corresponds to Al/P ratio = 1. The mechanical properties are correlated with the amount of amorphous phase in geopolymer which is determined by the Rietveld method. In addition to metakaolin, illite mineral contributes to geopolymerization.