Technology readiness: A global snapshot of 3D concrete printing and the frontiers for development

Since the inception of 3D concrete printing (3DCP) in the early to mid-2000's, the commercial landscape for this technology has expanded rapidly in parallel with developments of relevant materials, production technologies and knowhow. To benchmark the state-of-the-art of 3DCP technology in the construction field, this study presents a systematic review and analysis of 3DCP's development and applications based on information from articles, patents and publicly available data. An estimation of Technology Readiness Level (TRL) for 3DCP has been formulated through expert review, and the evidence suggests this is in the region of TRL6-7 similar to that reported for polymer-based fused deposition modelling processes. A new schema for the TRL assessment process is suggested and applied to two case studies: 1) the production of decorative works; 2) the fabrication of dwellings. Finally, we have identified four frontiers for research and development that should be exploited to raise the TRL of 3DCP.