Classification of robotic 3D printers in the AEC industry

Three-dimensional (3D) printing is a branch of additive manufacturing (AM) that works by slicing a 3D computer aided design (CAD) model into 2D layers and sequentially printing each layer additively until the entire object is obtained. There has been a growing interest in 3D printing in the architecture, engineering, and construction (AEC) industry because of its ability to lower costs, reduce waste, and simplify the supply chain. Due to the inherent nature of this technology, it requires a synergistic effort among experts in different disciplines such as architecture, material science, structural design, and robotics, to name a few. Previous studies have focused on the development, exploration, and investigation of the architectural, materials, and structural aspects. However, the robotic technology aspect received relatively less attention. Thus, the objective of this study is to critically review the existing 3D printing robotic systems in the AEC industry and to explicitly categorize them. At first, the literature related to 3D printing robotic systems in the AEC industry was studied, and the subjects which have not been discussed extensively were identified. Then, the gaps in the existing state of the art were identified, and lastly, a classification method was developed and discussed. To obtain the classification of the existing construction 3D printing robotic systems, five parameters were highlighted, namely fabrication place, fabrication type, materials used, 3D printer type, and 3D printing technology. In addition, the obtained classification was based on exploring the combinations of these parameters and their variations. The resulting classification could greatly assist and guide stakeholders' efforts to better understand and adopt 3D printing in current and future projects.