Abstract
Geopolymer foam is a lightweight and environmentally friendly material that utilizes byproducts as raw materials. It consists of precursors, alkaline or acidic solutions, and foaming agents, with the option to incorporate stabilizing agents. The presence of dispersed pores significantly enhances its insulation properties, resulting in a reduced overall density, improved mechanical energy absorption, increased fire resistance, and greater durability. As an innovative alternative to conventional insulation products, geopolymer foam not only enhances overall building performance but also allows for the creation of complex shapes through additive manufacturing (AM), which is particularly beneficial in the architecture and aerospace sectors. To further advance this innovative material, this critical review summarizes recent experimental studies on geopolymer foam mortar in 3D printing, examining selected peer-reviewed literature to evaluate the type of material formulations and performance characteristics. By identifying key trends, strengths, and research gaps, this study provides a comprehensive understanding of current progress and future directions in the development of sustainable, high-performance geopolymer foam materials for AM. This technology effectively reduces energy consumption in construction and lowers carbon dioxide emissions by incorporating industrial waste, thereby supporting sustainable development goals.