Life Cycle Assessment of Alkali Activator Solutions With Different Silica Modulus by ATR‐FTIR and ² ⁹ Si NMR: Influence on the Geopolymerization of Fly Ash ‐ GGBS System

In recent years geopolymers (GPs) gain significant attention due to their eco‐friendly nature and greater conventionality compared to ordinary Portland cement (OPC). Beyond replacing OPC, GPs play crucial roles in 3D printing technology, thermal resistance materials, aerospace materials, building constructions, and other emerging applications. However, the long‐term stability and storage behavior of alkali activator solutions with different silica modulus remain insufficiently understood, which limits their large‐scale application and commercialization. Our study primarily investigates the life cycle assessment (LCA) of different silica modulus of alkali activator solutions over a 1‐year period. We focused on observing the physical and chemical longevity of these alkali activator solutions and evaluating the effects of Na 2 O, SiO 2 , and Al 2 O 3 content from the alkali solution and aluminosilicates on the compressive strength of mortar. Despite the growing importance of GPs, their long‐term stability and durability largely depend on the alkali‐activated solutions. Understanding the LCA of these alkali‐activated solutions is crucial. Our research revealed that solutions with silica modulus values of 0.8 and 1.4 are stable over long periods, making them suitable for product formulations and practical applications toward commercialization. In contrast, the 1.2 solution undergoes rapid setting in GP mortar and crystallizes. The variation of pH, silicate structure, and reactivity with time, indicated that silica modulus plays a role in influencing the stability and performance of the alkali activator solutions. The durability assessments were analyzed through visual observation, pH stability, Fourier transform infrared (ATR‐FTIR) spectroscopy, and nuclear magnetic resonance ( 29 Si solid‐state NMR). Additionally, the reactivity of these alkali activator solutions in the geopolymerization of fly ash and ground granulated blast furnace slag (GGBS) was studied. The research aimed to understand how different silica modulus values influence the geopolymerization process and the resulting of mechanical properties of GPs. The findings indicated that the silica modulus significantly affects the reaction mechanisms and the structural integrity of the GP products. Solutions with a silica modulus of 0.8 and 1.4 showed enhanced geopolymerization activity, leading to higher compressive strengths and better overall performance in the fly ash and GGBS‐based GPs. These insights contribute to optimizing alkali activator solutions for developing durable and high‐performance GPs for various applications.