Alkali-activated binders (AAB) offer a sustainable alternative to Portland cement by utilizing aluminosilicate-rich industrial byproducts, forming hardened structures with hydrous alkali-aluminosilicates under alkaline conditions, thus enhancing sustainability. In order to create alkali-activated paver blocks (AAPB), this study focusses on using locally available industrial byproducts, such as fly ash from coal power plants and slag from the production of iron. This study deals with the comparison of using red gypsum, which is a readily available by product from titanium dioxide manufacturing industry, and phosphoric acid as admixtures in the production of paver blocks, in contrast to a control mix devoid of admixtures. Various control factors, such as Na2O/binder ratio = 6%, BFS/binder ratio = 0.5, activator modulus (Ms) = 1.5, and water/solids ratio = 0.45, are fixed. The study adopts an optimum dosage of admixtures as 10% of red gypsum by weight of binder content with 0.6 M phosphoric acid from the study on paste. The characteristics, such as compressive strength, split tensile strength, and water absorption, were evaluated in order to understand the hardened properties of AAPB. In comparison with the control mix, the findings indicate a marginal reduction in the hardened properties of the admixture mix AAPB. Even with this slight decrease, the AAPB are still suitable for practical applications. These findings encourage the further use of sustainable building techniques and provide insightful information for improving AAB systems for paver blocks.