A Simplified Mix Design for GGBS-Dolomite Geopolymer Concrete Using the Taguchi Method

Incorporating industrial by-products into the manufacturing of geopolymer concrete has the potential to make concrete production more environmentally sustainable. This research employs ground granulated blast furnace slag (GGBS) and dolomite as alumino-silicate base materials, and sodium hydroxide solution (NaOH) and sodium silicate solution (Na2SiO3) as the alkaline activators. The use of geopolymer concrete (GPC) allows for numerous design variables, which necessitates multiple trial experiments to determine an optimal GPC mix that achieves the desired strength. Therefore, the lack of a well-defined mix design process represents a notable obstacle to the industrial application of geopolymer concrete. In this study, the Taguchi approach is employed to optimize the mix design factors within the geopolymer concrete mixture, with a specific focus on achieving the desired strength criteria. The study includes a slump test, compressive strength test, and split tensile strength tests. The results of the tests match the target strength values, leading to the formulation of a mix design for GPC according to the Taguchi method, eliminating the need for extensive trials. The microstructure assessment of the mixtures, conducted through scanning electron microscopy (SEM), unveiled a more compact microstructure in the optimal blend. The CO2 assessment of GGBS-dolomite GPC highlighted a significant decrease in CO2 emissions when compared to an equivalent-grade normal concrete.