Improving Strength and Cohesion in 3D-Printed Soil Composites Using Xanthan Gum

The advancement of additive manufacturing, also known as 3D printing, has presented avenues for efficient and eco-friendly construction processes. Biopolymer-bound soil composites have been studied to determine their suitability for 3D printing. This study evaluates the use of xanthan gum (XG), a sustainable food-grade biopolymer, as a binder for kaolinite-based soils to improve the shear strength and the interlayer strength of 3D printed structures. The overall mechanical performance with increasing xanthan gum content (0%, 1%, and 2%) was evaluated using unconfined compressive strength (UCS). The interlayer bond properties and improvement were assessed to evaluate the effectiveness of XG in strengthening the interlayer weak interface, which is associated with 3D printed structures. Results show an increase in UCS with the addition of xanthan gum at lower concentrations compared with the untreated control specimens. The interlayer bond strength showed notable gains, with xanthan gum increasing the cohesion of the layers. This study highlights the potential of xanthan gum as a sustainable binder for soil-based 3D printing. By improving both the mechanical integrity and interlayer bonding of printed structures, XG could be used for more resilient, eco-friendly construction materials.