An experimental approach for the determination of the physical and mechanical properties of a sustainable geopolymer mortar made with Algerian ground-granulated blast furnace slag

Geopolymer technology is widely recognized and extensively tested as a sustainable alternative to conventional cement, with considerable environmental and economic benefits through waste management, however, it remains largely unstudied and underutilized in Algeria. Despite the abundant availability of aluminosilicate materials, there is only limited and incomplete research on pozzolans and metakaolins in the region. This paper aims to address this gap by investigating the use of Algerian ground-granulated blast furnace slag (GGBFS) to develop an optimal formulation for producing high-performance geopolymers. To determine the optimal combination of alkaline activators compatible with GGBFS and sand content, a series of experiments were conducted on fresh and hardened GGBFS-based geopolymer mortars to verify properties such as workability, setting time, water absorption, efflorescence stability, and mechanical strength. Techniques used to characterize the microstructure of a subset of geopolymer samples included Atr-FTIR, XRD, and SEM-EDS. This research not only emphasizes the environmental benefits of repurposing waste materials but also advances the development of more sustainable and durable geopolymer mortars, presenting a promising approach to improving environmental stewardship in material science practices.