A review of 3D printing of geopolymer composites for structural and functional applications

The 3D printing allows for the automated and quick building of structures, drastically reducing the time and labour necessary for traditional construction methods. An extensive analysis of more than 100 + articles aimed to present a thorough summary of the present research status on 3D printing of geopolymer substances, investigating different factors, including printing methods, material traits, and geopolymerization procedures. The fresh and mechanical properties result of 3D geopolymer composites are reviewed and represented in kernel density, radar, quantile-quantile plots, and multi-Y analysis plots for various binder ratios. The effect of Si/Al, activators, and factors that influence the acceleration of geopolymerization of 3D-based geopolymers is discussed. Different types of 3D printing machines, along with layer adhesion thixotropy and its relation to printability, printing speed, adhesion of layers, and storage condition, are studied, as are their mechanisms. Using pozzolanic materials in the chemical reaction between quicklime and silicate materials enhances the structural performance of the geopolymer material, resulting in superior properties. This review's findings and suggestions attempt to lay the foundation for future study in this field, which offers assistance in building 3D-printed composite materials with the necessary sustainability.