project summary: 

The urgent need to reduce emissions and material waste in the construction industry has renewed interest in pairing digital fabrication with low-carbon materials. Earth-based materials, among the oldest building materials globally, are increasingly revisited as low-carbon, locally sourced alternatives with significant architectural potential. However, the scalability of extrusion-based earthen construction remains fundamentally constrained by wet-state instability, which limits maximum continuous printable height and undermines fabrication reliability. Existing research addresses this primarily through material composition, often undermining the material’s inherent sustainability, or through fabrication timeline adjustments such as process pausing, multi-session printing, or forced drying, which increase fabrication overhead. This research proposes an alternative fabrication-integrated framework that enhances wet-state stability without altering material formulation. Two complementary strategies are investigated: Periodic Toolpath Modulation (PTM), which introduces coordinated geometric variation to redistribute stresses during deposition, and In-Process Reinforcement Integration (IPRI), which embeds temporary discrete elements to provide localised bracing during consolidation. Through multi-scale experimentation progressing from small-scale prototyping to full-scale robotic fabrication, the research establishes validated design-to-fabrication guidelines for improving buildability, geometric reliability, and fabrication continuity in earthen additive manufacturing, positioning fabrication logic as an alternative to material alteration. In doing so, this work lays the groundwork for wider integration of low-carbon, earth-based materials into mainstream digital construction practice. 

Keywords 

Earthen additive manufacturing, Buildability; Toolpath design; In-process reinforcement; Robotic fabrication; Sustainable construction