Mechanical properties of geomaterials formulated with clay and Parkia biglobosa (néré) extract

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Résumé

Researches for non-energy intensive construction products, that are durable and cheaper is today of global concern because of the limited resources (energy, financial, etc.). To
address this issue, the present work presents the combination of the decoction of pods of Parkia Biglobosa (néré) that is rich in tannins compounds including gallic acid, epicatechin
gallate and epigallocatechin, with a clay-sand mixture. The clay used is referenced KORO and contains montmorillonite, illite, quartz, albite, orthoclase, kaolinite and goethite. The
study of the mechanical properties of geomaterials formulated from the mixture shows that they have values of mechanical resistance higher and that their behavior becomes viscoplastic. This is due to the formation of chemical complexes from carboxylic groups of tannins macromolecules with the iron oxy-hydroxide in the interlayer spacing of clay
minerals. This process is enhanced by the sorption of tannins on the surface of clay minerals.

Mots-clés

Clay, Geomaterials, Tannins, Oxides iron, Pods of Parkia biglobosa