Geopolymers as a sustainable alternative to Portland cement: Synthesis, durability, applications, environmental impacts, and cost analysis

Geopolymers are emerging as a sustainable alternative to ordinary Portland cement (OPC), offering reduced CO₂ emissions, excellent mechanical and durability performance, and the potential to utilize industrial byproducts. Although numerous studies have reviewed the properties of geopolymers, limited attention has been given to their durability, environmental impact, and cost analysis. This paper explores the geopolymerization process and atomic structure of geopolymers. The durability properties, cost, and environmental impacts of geopolymer concrete were comprehensively reviewed and compared with those of OPC concrete. In addition, alternative alkaline activator replacements with commercial alkaline activators have been introduced. The literature indicates that the global warming potential (GWP) of geopolymer concrete is 16 % to 90 % lower than that of OPC concrete. However, geopolymer concrete has some minor drawbacks, including higher costs and other environmental impacts. The results also reveal that using alternative activators can reduce GWP by up to 61 % and the cost of geopolymer concrete by up to 58 % compared to commercially available activators. Finally, future perspectives are outlined to address current challenges and promote the wider adoption of geopolymers in construction.