Bio-Inspired Bouligand Architectures Enable Biaxial Toughening and Programmable Energy Dissipation in 3D-Printed Strain-Hardening Cementitious Composites (2026-03)¶

Despite continuous advances in concrete technology, its inherently low tensile strength and brittle fracture characteristics have long restricted its application to compression-dominated design paradigms. Robotic additive manufacturing (RAM), endowed with geometric programmability and meso-architected control, enables precise fiber alignment along deposition trajectories, thereby offering an unprecedented opportunity to transcend this long-standing limitation. Yet, the inevitable emergence of weak deposition interfaces unveils a critical, unresolved mechanistic incongruity between the continuity-centered material principle of cementitious systems and meso-architected functionality toward intelligent construction. This study introduces a process–structure–material integrated design strategy based on programmable robotic deposition, embedding the bouligand-inspired helicoidal sequence—unattainable through conventional casting—into 3D-printed strain-hardening cementitious composites (3DP-SHCC). Biaxial flexural tests reveal that the bouligand architecture reconfigures interfacial deformation and stress redistribution, thereby enhancing toughness and energy dissipation. Compared with its parallel-printed counterpart, the bouligand-architected specimen exhibits markedly higher flexural strength and energy dissipation, indicating a pronounced architecture-enabled enhancement in strength–toughness performance without altering the material composition or mix design. This work transforms weak deposition interfaces from intrinsic defects into programmable dissipation channels, demonstrating the potential of mesoscale architectural design to enhance energy dissipation in cementitious composites fabricated via RAM, and advancing digital construction strategies—from passive defect mitigation toward bio-inspired mesoscale architectures with programmable functionalities.