Recycling of induction furnace steel slag in concrete for marine environmental applications towards ocean acidification studies

In the present investigation, induction furnace (IF) steel slag as coarse aggregate with 0%, 20% and 40% replaced concrete specimens of size 150 x 150 x 150 mm was prepared as an initiative to utilize iron-rich IF steel slag. The casted concrete specimens were cured for 28 days at room temperature (28 degrees C) in freshwater, and the obtained compressive strength is 22.5, 24.0 and 29.2 N/mm(2), respectively. The blocks were then immersed in seawater under laboratory condition for 28 days, and variation in pH was monitored at regular intervals. The composition and mineralogical phases [quartz (SiO2), iscorite (Fe7SiO10), hematite (epsilon-Fe2O3) and almandine (Fe3Al2Si3O10)] present in IF steel slag were identified using XRF and XRD analysis, respectively. Surface morphology and elemental composition were studied using FESEM with EDAX analysis for before and after immersion of concrete blocks in seawater. Structural bonding of concrete blocks before and after immersion was studied using FTIR analysis. Compressive strength of concrete specimens after the immersion in seawater was evaluated and compared with before immersion in seawater. This initiative will be a major support for induction furnace steel industries via economic benefits. Utilization of iron-rich IF steel slag in marine concrete can be a vital candidate for the betterment of marine ecosystem via primary production of marine resources.