Enhancing multi-objective mix design for GGBS-based geopolymer concrete with natural mineral blends under ambient curing: A Taguchi-Grey relational optimization

Rising populations and industrial expansion necessitate sustainable alternatives to conventional cement -based concrete. Geopolymers, with their impressive mechanical properties, eco-friendliness, and potential for waste utilization, offer a promising solution. Yet, concerns like rapid setting and low workability limit their widespread adoption. This study addresses these challenges by optimizing a geopolymer concrete incorporating ground granulated blast furnace slag (GGBS) blended with bentonite and dolomite minerals. Employing the Taguchi method, we optimized the mix design considering key factors like binder content, mineral replacements, alkaline-to-binder ratio, and solution ratios. Grey-Relational Analysis identified the optimal mix with 10 % bentonite and dolomite replacement, a 0.55 alkaline-to-binder ratio, 12 M NaOH solution, and 425 kg/m 3 cementing materials. This optimized mix exhibited significantly improved setting times, enhanced workability, and the highest compressive strength among all tested mixtures. Experimental validation confirms its effectiveness, highlighting its potential as a sustainable alternative. Importantly, this research explores GGBS as a replacement for commonly used Fly Ash, further advancing sustainable construction practices.