Enhancing concrete with SCMs: unveiling the pros and cons of fly ash, silica fume, and slag

Abstract The performance of concrete that contains different amounts of fly ash, silica fume, and ground granulated blast furnace slag (GGBS) as partial cement replacements is examined in this study. Workability, water absorption, weight loss, strength loss, compressive strength, split tensile strength, flexural strength, and chloride ion permeability were assessed for 17 mix formulations at 7, 14, 28, 56, and 90 days. The Rapid Chloride Permeability Test (RCPT) was used to evaluate durability, while scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to analyze the microstructure and phase composition, respectively. With a compressive strength of 85.69 MPa at 28 days, split tensile strength of 5.82 MPa, flexural strength of 9.64 MPa, and water absorption of 1.21% after 90 days, the ideal mixture of 7.5% fly ash, 7.5% silica fume, and 7.5% GGBS demonstrated the optimum performance. Losses in weight and strength were negligible, at 0.85% and 2.37%, respectively. There was little chloride permeability (815 Coulombs). A dense microstructure was seen by SEM, and further C-S-H development was verified by XRD. A score of −2.45% from the Percent Bias (PBIAS) study indicated that the model prediction was accurate. All things considered, blended cementitious ingredients improve mechanical and durability qual-ities while encouraging environmentally friendly concrete production by using less cement.