Physico-Chemical Properties of Geopolymer Binders Made from Tunisian Clay

摘要

The suitability of illito-kaolinitic clay from Tejra in south Tunisia was investigated in view of producing geopolymer binders. The effects of activator concentrations on compressive strength, water absorption (durability), open porosity and bulk density of geopolymers cement were examined,in order to assure optimal geopolymerization conditions. Raw clay was calcined at 950 °C for 2 hours and activated along with various NaOH concentrations (8 to 18 M). Geopolymer cements aged 28 days with optimum performances were achieved when the clay was calcinated at 950 °C, andactivated with 13 M of the alkaline solution concentration. At these conditions, the compressive strength of prepared geopolymers reached 27.8 MPa whereas open porosity and water absorption values were 2.9% and 2.4% respectively. It could be concluded that geopolymer cement based on calcinedTunisian clay can be recommended as sustainable and cost-effective cement that may be applied as alternate Portland cement in many construction applications.