Abstract
The geopolymerization is a geosynthesis reaction based on the chemical minerals integration. Several parameters such as type of aluminosilicate mineral, the solid/liquid ratio, the concentrations of silicates and alkaline solution interpolate along the process. This work aims to investigate the effect of the starting material type, the Si/Al ratio, the calcination temperature and the reaction kinetics in the hydrothermal synthesis process. Analytical methods such as XRD, FTIR, SEM and NMR, are used to achieve this goal. Results shows, that the final product microstructure depends on the aluminosilicate sources and the Si/Al ratio. A variable microstructure is observed by varying Si/Al ratio. The surface morphology studied by SEM shows the effect of the temperature calcinations increase on the homogeneity of the obtained fibrous surface at 500° C. The SEM analysis demonstrates that microstructure is composed of dense particles with large pores interconnected. The nature and the characteristics of the final product are affected by the increase of the calcinations temperature. By following the reaction kinetics, in the case of metakaolin (obtained from Tamra Kaolin) reported at 800 °C, a fast material response is noted and the first microstructure change appeared after 1hr of treatment.
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•The final product is more amorphous for the high calcinations temperature.•Disappearance of the precursor mineral in the case of high calcinations temperature.•The geopolymerezation process remains incomplete at 500 °c.•The geopolymer microstructure depends on the aluminosilicate and the Si/Al ratio.•A fast materials microstructure response is obtained after 1 h