Development of calcium sulfoaluminate cements from rich-alumina bauxite and marble wastes: Physicochemical and microstructural characterization

Abstract

This work discusses the effect of rich alumina bauxite on the mineralogical composition of calcium sulfoaluminate (CSA) clinker cement on their performances. After preparation of different local raw materials (rich alumina bauxite and marble), they were mixed with 15 wt% of commercial gypsum and pressed at 2 MPa. The obtained pellets were thermally treated at 1200°C to produce clinker, which is use to synthesize the CSA cements. The raw materials as well as products were characterized by many analyses, such as FT-IR, X-ray fluorescence, X-ray diffraction, differential scanning calorimetry (DSC)/thermogravimetry analysis (TGA), isothermal calorimetry (ICC), scanning electron microscope, and physico-mechanical tests. ICC analysis of the powder of clinker cement showed that the reactions are strongly affected by gypsum content. XRD results revealed that clinker and cement present a strong intensity of ye'elimite as main mineral phase. Moreover, the hydrated cement exhibited ettringite and monosulfate as the new phases formed. The compressive strength of hydrated cement reached ∼21 and 28 MPa after 1 and 28 days of curing, respectively. From the aforementioned results, this local rich alumina bauxite can be used to produce high-strength cement for self-leveling materials, which allow their use in engineering and building applications.