Structural performance of 3D concrete printed load-bearing walls

Modern construction techniques have evolved in recent years with the introduction of 3D concrete printing (3DCP) technology. This innovative digital construction approach offers rapid, cost-effective, and sustainable solutions. The 3DCP walls used as load-bearing walls are an essential component and the primary section of the 3D printed constructions. Therefore, this study investigates the behavior of large-scale 3DCP walls under axial loading to evaluate their load-bearing capacity. The used mix consists of optimized materials, including glass fibers (GF) for fiber reinforcement, enhanced mechanical properties, and crack resistance. Rheological testing ensured the mix's quality and efficiency, assessing properties like extrudability, flowability, and buildability. Mechanical tests confirmed the mix as high-strength concrete with 85 MPa compressive strength. Uniform axial compression loading tests were conducted to analyze the structural behavior, deformation, and crack patterns of 3DCP load-bearing walls with different cross-section configurations. The walls were categorized into two types: gapped walls, which include GLBW-3T (three-truss gapped wall), GLBW-4T (four-truss gapped wall), and GLBW-5T (five-truss gapped wall), and a solid wall (SLBW), which is a fully solid section designed to achieve the sectional maximum load-bearing capacity. In this study, material consumption was a key factor in identifying the optimal and economical structural efficiency. The SLBW exhibited the highest resistance to cracking with a crack load-to-volume ratio of 4.02 N/cm3. Conversely, GLBW-3T and GLBW-5T, both featuring gapped sections with varying truss configurations, showed similar efficiency with crack load-to-volume ratios of 3.12 N/cm3 and 3.04 N/cm3, respectively. GLBW-4T demonstrated the least efficient performance, with a crack load-to-volume ratio of 2.48 N/cm3. Moreover, the crack pattern intensity and structural stability were highest in the SLBW, followed by the GLBW-3T, while, the GLBW-5T performed the least favorably. This study underscores the superior structural performance and material efficiency of the GLBW-3T configuration, achieving an optimal balance of material use and structural integrity.