A sustainable roadmap for additive manufacturing using geopolymers in construction industry

Recently 3D printing of geopolymers gained increasing attention due to their dual-dimensional sustainability from technology and materials perspectives. The current research first defines the criteria for the assessment of the sustainability of 3D printed geopolymers. Four different aspects including productivity assessment, economic influence, environmental burden and social impact have been investigated to analyze their current states of sustainability. Detailed productivity analysis depicts promising results in terms of fresh and hardened properties of 3D printed geopolymers. Despite reasonable productivity, 3D printing of geopolymers has not completely replaced the traditional practices and materials on industrial scale as a result of their inadequate economic and environmental performance mainly due to alkaline reagents. Alkaline reagents used for the geopolymerization of industrial by-products not only increase the overall concrete cost but also induce a severe environmental burden. Although, 3D printed geopolymers have explicit social impacts on human lives, the high level of automation in 3D printing process and less manufacturing of cement (due to its replacement with geopolymers) may reduce the number of jobs. Upon critically analyzing the pros and cons, a strategic roadmap is provided for the adoption of the 3D printing of geopolymers on industrial scale based on short, medium and long-term goals.