High performance illitic clay-based geopolymer : Influence of the mechanochemical activation duration on the strength development
Résumé
Demonstrate the feasibility of an illitic clay-based geopolymer is the purpose of this study. If the thermal activation of standard precursors such as kaolin is a well-known process, the reactivity of illitic precursors required the combination of thermal and mechanochemical activation. The structural changes of the precursor material submitted to various grinding durations were followed by X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) and the amorphous phase rate calculated from XRD analyses was correlated with this parameter as well as the compressive strength (Rc) of the manufactured geopolymers. Mechanical properties increased with the grinding time and the decrease of L/S ratio of the geopolymer paste. Illitic clay-based geopolymers may reach high performance as demonstrated with a Rc at 28 days reaching 102 MPa. Finally, the relations between the amorphisation rate and the compressive strength of the geopolymers have been highlighted