Framework for technical specifications of 3D concrete printers

In this paper, we propose a technical specification framework for three-dimensional concrete printers (3DCPs) by analyzing 139 academic papers from 1997 to 2020, 98 3DCPs, and a Delphi survey with 22 3DCP experts. Despite the rapid growth of 3DCP research and market, there is no commonly acceptable technical specification framework for comparative analysis of 3DCPs with diverse characteristics. For deriving a common technical specification framework for various 3DCPs, this study first compiled 1604 technical specification items through a literature review. The technical specification items were restructured into nine categories and 90 items by removing identical terms, merging synonyms, and excluding items that appeared only once. The 3DCP expert panel reached a consensus on 86 items as significant 3DCP properties following three rounds of a Delphi survey. Finally, a 3DCP technical specification framework with 19 core and 67 supplementary technical specification items in nine categories was proposed based on the analysis.