Experimental study and design approach on 3D printed concrete walls under eccentric axial compression

To study the structural behavior and failure modes of 3D printed concrete walls under eccentric axial compression, ten 3D printed concrete wall specimens were designed with varying strength grade of concrete material, cross-sectional forms, and reinforcement rates. From the experimental phenomena, three typical failure modes were identified. The results have shown that increasing the reinforcement rate has a minor impact on the bearing capacity of the wall, but it can significantly enhance the ductility of the specimen. Furthermore, the cement strength grade within the wall significantly influences its performance. A higher cement strength grade results in greater overall stiffness and reduced vertical displacement. The w-shaped cross-sectional form of the wall exhibits superior mechanical properties due to its ability to enhance the wall's integrity. The connection between the reinforcements and mortar in the reserved holes is reliable, effectively transmitting bonding stress and ensuring the continuity of the overall force transmission of the reinforcements in the wall. Finally, the compressive stress distribution of the wall was studied through finite element simulation, and the effective compressive area of the wall section was calculated. The existing formulas for calculating positive section bearing capacity were enhanced and validated, providing a theoretical foundation for the future application of 3D printed concrete components in real-world projects.