The suitability of thermally activated red illite/kaolinitic clay as raw material for geopolymer binders

This study evaluates the use of tunisian hematite rich clay as aluminosilicate source for geopolymer synthesis. the clay fraction was heated at 750 and 950 °c for 2h and then activated by potassium hydroxide and sodium silicate. the heated clay induce various reactivities according to the results obtained by xrd, ^27al mas-nmr, thermal analysis (dta), particle size distribution and specific surface area. after geopolymerization, the compressive strength of the hardened geopolymer cement (as an indicator of clay reactivity) increased with the heat treatment. it can be concluded that the most convenient temperature for the heated clays in view of producing geopolymer cements is obviously around 950 °c.