Review of material–process–structure synergy and engineering applications of spray-based 3D concrete printing

Spray-based 3D concrete printing (S-3DCP) offers advantages in formwork-free fabrication, multidirectional deposition, and reinforcement integration, yet material–process–structure synergy and engineering evaluation remain insufficiently understood. Taking this synergy as the central framework, this review synthesizes S-3DCP studies published up to 2026 and establishes a technological framework covering material design, process control, reinforcement integration, and engineering applications. The results show that stable fabrication depends on the coordinated matching of material properties with equipment and process conditions, while interlayer interface formation and reinforcement encapsulation affect structural performance. Future research should develop transferable evaluation frameworks and closed-loop control methods and strengthen full-scale structural and long-term service validation.