Geopolymer additive manufacturing: A review

This paper analyzes the current development of additive manufacturing (AM) technologies exploiting geopolymers (GPs) as promising green and sustainable 3D printable aluminosilicate inorganic materials. Material design and processing strategies to achieve or enhance three-dimensional printability of various geopolymer systems are summarized. The main methods of GPs additive manufacturing based on material extrusion and powder-based printing processes are considered. Their features, advantages, and limitations are scrutinized. There is presented a brief description and a principle of operation of the varieties of 3D printers, with whose help these fabrication approaches are implemented. Fresh and hardened state properties of 3D printed GPs are discussed in detail from the point of view of chemical reactions and structural transformations occurring in the material. The areas and specific examples of the application of advanced printable geopolymer materials and products are surveyed. The main current challenges, perspectives and directions of future work required to improve this technology have been delineated.