A Critical Review of 3D Printed Concrete Material Properties, Structural Performance, and the Way Forward

Abstract Three-dimensional (3D) concrete printing (3DCP) has emerged as a transformative technology, offering enhanced efficiency, sustainability, and design flexibility compared to conventional construction methods. Despite substantial progress, regarding material development challenges, such as the lack of standardized testing protocols, limited research on structural performance, durability, reinforcement integration, and connection strategies hinder the widespread adoption of 3DCP. This manuscript explores the current state of 3DCP, with a focus on mechanical properties of the 3D printable material for structural design, structural capacity estimations, and 3D printed concrete (3DPC) element connection details. Using the available research literature, the correlations for the hardened-state properties of 3DPC are presented, which can be used in structural design and code development. Further, the structural capacity equations for 3D printed walls and columns are discussed. Finally, several connection design schemes, suitable for 3DCP construction, are proposed. The practical issues in 3DCP and open research areas are discussed in detail.