Plastic Deformation Induced Non-Uniform Global Distribution of Microstructure and Related Performances Within 3D Printed Concrete (2026-03)¶

Due to the absence of formwork, plastic deformation significantly affects the performance of 3D printed concrete (3DPC). Specifically, within large-scale 3DPC structures, non-uniform plastic deformation induced by constraints may lead to a heterogeneous global distribution of performance, which is critically important for overall performance prediction and control. However, in the current research progress, this issue has not yet been thoroughly investigated. To this end, this study highlights the non-uniform global distribution of microstructure and related performances originating from non-uniform plastic shrinkage deformation within multilayer 3DPC structure. We firstly reveal a recovery process of pores from flattened to more spherical states within 3DPC during plastic deformation, which can be further amplified by capillary pressure. By hindering this process, the mechanical anisotropy coefficient at constrained location can be 346% higher. Meanwhile, constraint induced pore coarsening was observed, leading to 25.3% lower flexural strength and 48.9% higher water sorptivity at constrained location. In addition, the non-uniform deformation can induce interlayer weakening. When combined with the compaction effect of gravity, the interlayer bonding strength in the structural top location can be 19.2% lower than that in the bottom location. This study points out the critical regions and governing trends by which plastic deformation influences the mechanical and transport properties within 3DPC structures, providing valuable reference for performance control and optimization in large-scale 3DPC structures.