Geopolymers are a sustainable alternative to Portland cement, with the potential to significantly reduce the carbon footprint of conventional cement production. This study investigates the valorization of industrial waste iron powder (IP) as a fine filler in geopolymers synthesized from volcanic tuff (VTF). Composites were prepared with IP substitutions of 5%, 10%, and 20% by weight, using sodium hydroxide and sodium silicate as alkaline activators. Microstructural and phase analyses were conducted using scanning electron microscope coupled with energy dispersive X-ray spectroscopy (SEM-EDS), X-ray fluorescence (XRF), X-ray diffraction (XRD), and differential scanning calorimetry (DSC), while rheological properties, compressive strength, and flexural strength were assessed. The impact of curing temperatures (25 °C and 80 °C) on mechanical performance was evaluated. Results revealed that air content increased to 3.5% with 20% IP substitution, accompanied by a slight rise in flow time (0.8–2 s). Compressive and flexural strengths at 25 °C decreased by up to 22.48% and 28.39%, respectively. Elevated curing at 80 °C further reduced compressive and flexural strengths by an average of 45.30% and 64.68%, highlighting the adverse effects of higher temperatures. Although these formulations are not suitable for load-bearing applications, the findings suggest potential for non-structural uses, such as pavement base layers, aligning with sustainable construction principles by repurposing industrial waste and reducing reliance on energy-intensive cement production.

Currently, the use of geopolymers as cementitious materials is constantly evolving due to their excellent properties and efficiency, such as low CO2 emissions, high compressive strength, and low permeability. On the other hand, volcanic tuff can be used as a potential raw material for synthetic geopolymers due to its reactivity, wide availability in nature, low extraction cost, and relatively low environmental impact. This paper presents a review of recent studies on the use of volcanic tuff as a main binder in the manufacture of geopolymers. The results reported by the researchers concern durability and mechanical performance, as well as the factors affecting these properties, such as the effect of activator types, sodium hydroxide (NaOH) concentration, curing temperature, and the addition of other cementitious materials. The results clearly showed that increasing the activator concentration and curing temperature had a significant effect on mechanical properties, as well as that the activator (Na2SiO3 + NaOH) reduced water absorption values by creating a more compact structure in all samples than activation by NaOH alone. Recent results suggest that volcanic tuff-based geopolymers have mechanical, physical, and durability properties similar to or better than those of ordinary Portland cement concrete, but further research is needed to make them an economically and technically efficient building material.