Fresh and hardened properties of cement paste blended with iron-rich calcined vanadium tailings containing kaolinitic clay

This study investigates the hydration behavior of blended cement pastes incorporating iron-rich calcined vanadium tailings (CVT) as a supplementary cementitious material (SCM). The fresh state and hardened state properties of cement pastes incorporating CVT were studied. Thermogravimetric analysis, X-ray diffraction, Fourier-transform infrared spectroscopy, and scanning electron microscopy were used to analyze the hydration, mineralogical changes, molecular structure, and microstructure of Control and CVT-blended cement pastes. The results confirmed the pozzolanic reactivity of CVT in CVT-blended cement paste samples, evidenced by portlandite depletion, gypsum consumption, and carbonate phase evolution. The formation of Strätlingite and iron-substituted hydrogarnet was observed in the mineralogical analysis of the CVT-blended cement paste. Incorporation of 10% CVT enhanced compressive strength and thixotropy index, with slightly reduced flowability. The findings of this study demonstrate the potential of CVT as a sustainable SCM and provide deeper insight into its influence on the hydration mechanisms of CVT-blended cement paste.