Physicochemical and Mineralogical Characteristics of Geopolymer Formulated from Kaolinitic Clay

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Résumé

Canola meal as a by-product from the vegetable oil production provides a protein-rich material which is available This study investigated the potential of Burkina Faso’s local kaolin clay in formulation of geopolymer bricks. The formulation used a mixture of raw clay and activator alkaline solutions with varying concentrations. Prismatic molds were used to shape geopolymerized adobes. The physicochemical characteristics of the samples, including water absorption, linear shrinkage, density, porosity and spray test, were determined after 28 days. According to the standard NF P 15-471 mechanical analyses revealed that the geopolymer, formulated from locally sourced clay and a (NaOH + sand) solution with 10M concentration, exhibited favorable performance characteristics essential for civil engineering construction. These include a maximum linear shrinkage of 5.31%, a density ranging from 1.607 g.cm-3 to 1.900 g.cm-3, porosity of 29.90%, acceptable mass loss following a rain erosion test of 0.56%, and excellent compressive strength of 28 MPa. Mineralogical characterization results demonstrated that all formulated bricks contain quartz, kaolinite, goethite and a novel phase Na2(AlSiO4)6(OH)2.2H2O.

Mots-clés

Porosity, Geopolymer, Raw material, Compressive strength, Shrinkage, Goethite, Bauxite, Bulk density