Akademik Veri Yönetim Sistemi
JOM, 2025 (SCI-Expanded, Scopus)
This study investigates the physico-mechanical properties and phase-microstructure evolution of geopolymer mortars incorporating chromite ore waste (CW) as a partial substitute for fly ash (FA) and blast furnace slag (S). CW was added at 10–20 wt.% replacement levels, and the mixtures were activated using either sodium hydroxide (NaOH) or sodium silicate (Na2SiO3). All mortars were thermally cured at 90°C for 24 h. The raw materials (CW, FA, S) were characterized by X-ray fluorescence (XRF) and scanning electron microscopy with energy-dispersive spectroscopy (SEM/EDS), while phase identification of hardened mortars was performed using X-ray diffraction (XRD). Fresh and hardened properties, including flowability, unit weight, flexural, and compressive strength, were investigated. Results showed that increasing CW content from 10% to 20% slightly enhanced compressive strength, particularly in slag-based mortars, owing to the synergistic effects of CaO in slag and MgO in CW. Control mortars primarily formed sodium–aluminum silicate hydrate (N-A-S-H), quartz, calcium silicate hydrate (C-S-H), and anorthite phases. In contrast, mortars with 20 wt.% CW exhibited additional akermanite and hydrotalcite crystals, attributed to the higher MgO and SiO2 levels in the waste. These crystalline phases contributed to improved densification and strength. Overall, CW incorporation up to 20 wt.% enhanced the performance of Na2SiO3-activated mortars, confirming CW as a promising sustainable precursor for geopolymer production.