Utilization of industrial by-products in sustainable geopolymer concrete: a comprehensive review

Geopolymer concrete (GPC) is a novel environmentally sustainable substitute for Ordinary Portland Cement (OPC), providing superior strength, durability, and markedly reduced carbon emissions. The present study assesses the efficacy of several GPC systems, highlighting the influence of critical factors such as activator molarity, water-to-binder (W/B) ratio, silica modulus, and alkali concentration. Research indicates that elevated NaOH molarity and optimized sodium silicate to sodium hydroxide (SS/SH) ratios improve early-age strength, while increased W/B ratios extend setting durations. Combinations such as FA-GGBFS and FA-MK exhibit synergistic enhancements in compressive strength, durability, and microstructural density. Heat curing expedites geopolymerization, although ambient curing is viable with particular mix designs. Applications encompass structural components, pavement blocks, and geopolymer bricks, exhibiting enhanced resistance to sulfate attack, thermal stress, and chloride infiltration. This review emphasizes the potential of GPC in sustainable building while simultaneously confronting issues associated with precursor variability, activator costs, and setting regulation. The study adopts the approach of a systematic-narrative review in order to ensure methodological rigor and clarity regarding how the existing knowledge on geopolymer concrete is synthesized. Literature was then collected using defined keywords related to industrial byproducts and geopolymer materials from Scopus, Web of Science, ScienceDirect, and Google Scholar databases. Selected studies were thematically categorized on the basis of precursor characteristics, activator chemistry, mechanical behavior, and environmental benefits. This structured approach will ensure that the review is comprehensive, unbiased, and technically robust. The results endorse GPC as a feasible, low-carbon alternative to OPC, facilitating the worldwide transition towards more sustainable infrastructure solutions.