Performance evaluation of sustainable geopolymer concrete produced from ferrochrome slag and silica fume

Abstract

The main intention of this research is to reuse the industrial by product ferrochrome slag and silica fume as a partial replacement of natural coarse aggregate and fly ash, respectively for the production of Geopolymer concrete with improved mechanical properties. Natural coarse aggregate was replaced by ferrochrome slag (FS) in varying percentages from 0 to 40% by weight. Fly ash was replaced by silica fume (SF) at different percentages 0 to 15% by weight. The combined effect of FS and SF was studied by developing Geopolymer concrete. Tests for compressive strength, splitting tensile strength and flexural strength of the GPC have been carried out at 7, 28 and 90 days of curing. The scanning electron microscope (SEM) was performed for the inspection of surface texture of the microstructure of the hardened samples. X-ray diffraction (XRD) was conducted to investigate the crystallinity of the mineral phases of the material as well as the activation product. Fourier transformed infrared spectroscopy (FTIR) was carried out to know the degree of polymerization of the samples. At 28 days, compressive strength, splitting tensile strength and flexural strength of GPC produced by replacing 30% FS and 10% SF increases by 38.9%, 47% and 20.4% respectively. Acronyms: CS Compressive strength; FS Ferrochrome slag; NCA Natural coarse aggregates; NFA Natural fine aggregates.