Advancements in 3D soil printing for construction: Material development and technological challenges

Soil-based 3D printing has emerged as a potential solution for sustainable construction, due to growing concerns over the environmental impact of cement-based materials. However, the limited understanding of soil printability, material behaviour, and performance under real-world conditions remains a significant barrier to its application. This review provides an in-depth evaluation of material performance and technological challenges of soil 3D printing with a special focus on the extrusion-based printing method. Furthermore, this study explores the fresh and hardened state properties of soil-based mixtures, highlighting the importance of rheology in achieving extrudability and buildability during the printing process. Notably, the incorporation of certain additives has been shown to reduce shrinkage by up to 50% and increase compressive strength by 10–30%, although results remain highly dependent on soil type. The environmental assessments indicate that soil 3D printing can reduce the carbon footprint by up to 20% compared to traditional construction methods, especially when local or excavated soils are used. Despite these advancements, challenges persist in standardising mix designs, managing variability in soil composition, and ensuring long-term durability under environmental exposure. To advance soil-based 3D printing in sustainable construction, it is important to integrate soil mechanics principles, standardise testing protocols, and validate results at the field scale.