Cross-Layer Reinforcement Robot for 3D Printing Concrete : Hardware, Software, and Validation

A significant technical challenge faced by 3D printing concrete (3DPC) is integrating reinforcing materials, such as steel fibre and rebar, across multiple layers. Additionally, an automated reinforcement process is essential to ensure the installation precision of the reinforcement and maintain the construc-tion efficiency of 3DPC. This study proposes a robotic system to achieve collab-orative work between cross-layer reinforcement installation and concrete print-ing. The proposed system consists of two main modules: a concrete printing module and a cross-layer reinforcement installation module. This study devel-oped a simple Cartesian robot as a preliminary cross-layer reinforcement instal-lation module, which can work with a gantry-style 3D printer. A set of software based on Robot Operating System 2 was used to control the robot’s actions. The robot has three linear joints and one revolute joint, the revolute joint enables the insertion of cross-layer reinforcement at different angles. With specially de-signed end-effectors, this robot can handle different reinforcing materials. Steel fibre and U-shaped steel rebar were adopted to rein-force the printed concrete, and then X-Ray Computed Tomography (XCT) scanning analysis was used to verify the reliability of this system.