Towards a Design-to-Fabrication Workflow for 3D Concrete Printed Drainage Invert Shell Structures (2025-10)¶

This study presents an industry-driven investigation into the use of 3D concrete printing (3DCP) for fabricating custom drainage invert structures. Traditionally, such components require complex formwork, labor-intensive casting, and manual finishing. 3DCP offers a material-efficient alternative but faces challenges when complex shell geometries are sliced and printed without considering fabrication constraints. This often leads to defects like misaligned layers or geometric inaccuracies, reducing print success and scalability. To address these issues, the study introduces an integrated, scaffold-free design-to-fabrication workflow that combines parametric modeling, geometry-aware slicing, custom toolpath generation, and performance-driven analysis. The workflow seeks to reduce print time and material use while ensuring mechanical and geometric integrity. Validation is conducted through digital simulation, PLA prototyping, and material-specific parameter calibration. The proposed approach aims to streamline 3DCP for infrastructure applications, particularly those requiring hollow, self-supporting forms, and lays the groundwork for broader adoption of performance-aware digital construction methods.