Alternative geomaterials using laterites: reactivity and properties of use
Résumé
Lateritic soils resulted from an alteration of clay via accumulation of iron, Fe3+, or aluminium, Al3+, species. The lateritic soils constituted of concentrated ions oxide of iron, silicon and/or aluminium,
with kaolinite, halloysite, montmorillonite as predominant minerals clay. Nowadays various stabilization techniques have been often used to improve the structural, microstructural properties of laterites
such as chemical and mechanical stabilization. Numerous studies have been conducted on stabilization of raw or calcined laterites using the aforementioned stabilizers above. The aim of the present
work was to investigate the behavior of the iron minerals in two lateritic soils (different in iron content) during the consolidation process with acid or alkaline solutions. 57Fe Mössbauer spectroscopy
was used to monitor any changes in the iron valence and coordination number occurring during the geomaterials process and the consolidated products were also characterized by electron paramagnetic
resonance (EPR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and compressive strength measurements. The state of consolidation will be determined through the measurements of the properties of use and correlated with the microstructure.