Fabric evolution of a double-structured 3D-printed clayey soil upon drying

¹ University of Palermo, Engineering Department, 90128 Palermo, Italy
² Department of Civil and Construction Engineering, Centre for Sustainable Infrastructure, Swinburne University of Technology, Hawthorn, VIC 3122, Australia
³ Soil Mechanics Laboratory, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland

^* Corresponding author: marco.starvaggi@unipa.it

Abstract

3D printing of soils is an emerging additive manufacturing technology with significant potential for various geotechnical applications. These include automating the construction of earth-based houses using locally available soil to reduce the carbon footprint of the building process, as well as constructing infrastructure such as embankments for roads or dams, clay liners for landfills, and engineered barriers. Moreover, due to its flexibility in designing varying printing geometries, 3D printing in geotechnics offers the unique ability to produce soils with a distinct double-structured fabric, enabling the customization of geotechnical properties. Despite its potential, this technology remains in its early stages, with current applications largely developed through empirical approaches. Additionally, existing literature lacks studies adopting a geomechanical perspective. A robust understanding of the hydro-mechanical behaviour of 3D- printed soils is crucial for predicting their performance in geotechnical applications and advancing this emerging technology. To address this gap, this study investigates the drying behaviour of a double- structured 3D-printed soil from its as-printed state, with a particular focus on fabric evolution at both the micro and macro scales. The results provide initial insights that will contribute to the future development of a comprehensive hydro-mechanical model for 3D-printed double-structured soils.