Production of mortars using novel glass-ceramic porous spherical particles with chemical composition into SiO2-CaO-Al2O3-MgO quaternary system as replacement of sand aggregates

A novel production of new aggregate for mortars based on glass-ceramic porous spherical particles into SiO2-CaO-Al2O3-MgO quaternary system is reported. Crystalline blast furnace slags (c-BFS) are transformed into new glass-ceramic porous spherical materials with lower density than their precursor. The conversion occurs by c-BFS projection into an oxygen/Liquefied Petroleum Gas (LPG) plume-flame. The aim of the present work is to evaluate these new materials as aggregates to replace the sand in conventional mortars formulations in order to indicate a potential way to reduce the use of this mineral resource and also how industrial wastes can be transformed in useful materials with direct application into the construction materials field. The characterization of the precursor and products were carried out by optical microscopy; scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD) and their densities were measured by Helium pycnometry. Additionally, the compressive strengths at different aging times (7, 14 and 28 days), from a control sample and diverse mortars based on glass-ceramic porous spherical particles were evaluated. Finally, thermal conductivities from all the specimens cured at 28 days were also measured.