Energy efficient cement free binder developed from industry waste-A sustainable approach

In this paper, the physicochemical properties and hydration mechanism of cement-free binders developed from fluorogypsum has been discussed. The results showed maximum attainment of strength (38MPa), low water absorption (<5%) and porosity (<10) with anhydrous calcium chloride and sodium sulphate activators. The enhancement in strength with hydration period was due to the conversion of fluorogypsum into gypsum through formation of intermediate unstable salt. The reaction products were characterised using X-ray diffraction and scanning electron microscopy (SEM) techniques. SEM studies showed the appearance of prismatic and needle-shaped crystals of variable sizes interspersed with anhydrate fluorogypsum plaster which make matrix dense and compact. This change in morphology of anhydrite plaster is responsible for enhancement in strength, reduction in water absorption and porosity of cement-free binders. The engineering properties of the construction materials for use in plastering, masonry works, concrete, blocks and tiles developed from this binder are reported.