Investigation of the Relationship between Ferrochrome Ash Addition and Chemical Binders in Geopolymer Concrete

Abstract

Portland cement, widely used in construction, has high energy consumption and CO2 emissions during production. Seeking eco-friendly alternatives, geopolymers offer high strength, heat resistance, eco-friendliness, and acid durability. This study uses waste ferrochrome ash from Elazıg Eti Krom Factory as a pozzolan, activating it with NaOH and SiO2Na2O. It aims to assess the use of ferrochrome ash in geopolymer concrete for reduced CO2 emissions and waste valorization. Geopolymer concrete mixtures were prepared using ferrochrome ash in combination with blast furnace slag and silica fume, and their hardened properties were evaluated. Experiments with determined parameters—curing conditions, activator content, and sodium silicate (SS)/sodium hydroxide (SH) ratio—maintain consistency in geopolymer concrete. An extensive analysis of mechanical properties determines the optimal activator proportions as an SS/SH ratio of 3 with a NaOH molarity of 14. The top-performing mixture achieves an average compressive strength of 29.51 MPa following heat curing, underscoring the potential of ferrochrome ash as an effective additive in geopolymers, particularly at 60°C curing temperatures.