Innovation of Building Materials: Ecological Bricks, Characterization of Complementary Inorganic Raw Materials

Morphological, chemical and mineralogical characterization of inorganic raw materials (pumicite and heavy clay) was carried out by SEM-EDS, XRF and XRD. It was found that pumicite shows the following composition; 71.78% SiO₂, 14.83% Al₂O₃, 2.57% Fe₂O₃, 2.32% FeO, 2.37% Na₂O, 4.12% K₂O, 1.51% CaO and 0.5% P₂O₅. The major phase corresponds to Sanidine and as minor phases are Berlinite, Alkaline calcium and sodium ferritesilicoaluminate and Tridymite. For heavy clay, there was a chemical composition of 63.0% SiO₂, 19.9% Al₂O₃, 6.2% Fe₂O₃, 1.5% Na₂O, 2.1% K₂O, 3.9% CaO, 2.5% MgO and 0.9% TiO₂. Also are present in some contents of Illite, Kaolinite and Tridymite; Quartz, Hematite, Vermiculite and Montmorillonite are presented as minor phases. Additionally, the Atterberg number and the thixotropy were determined to heavy clay, finding values of 31.31 ± 9.45% and 2.87 ± 1.64%, respectively.