Importance and potential of cellulosic materials and derivatives in extrusion-based 3D concrete printing (3DCP): Prospects and challenges

[Display omitted] •Extrusion-3DCP is thwarted by critical issues related to its materials selection.•Potential benefits of cellulosic materials (CMs) and derivatives in extrusion-3DCP are reviewed.•CMs and derivatives potentially improve extrusion-3DCP mix design approaches.•CMs and derivatives offer potential internal curing options for extrusion-3DCP.•CMs and derivatives offer potential numerous hybrids, and multi-scale combinations for extrusion-3DCP. Three-dimensional concrete printing (3DCP) is an emerging digital construction technique, thwarted by critical issues related to its material design and preparation. These problems demand innovative and sustainable solutions. Cellulosic materials (CMs) are the most bountiful natural polymers and are superb starting materials for the large-scale manufacturing of sustainable chemicals and derivatives. This article presents innovative ideas for the viable use of CMs and derivatives in extrusion-based 3DCP (E-3DCP). In the light of a detailed literature review, the CMs and derivatives were critically analyzed based on their attributes, and potential combinations along with their limitations, possible side effects, and incompatibilities with other raw materials and admixtures currently used in E-3DCP. The potential efficacy of CMs and derivatives in E-3DCP may have been overlooked. Accordingly, a structured classification of CMs and derivatives is proposed for E-3DCP. CMs and derivatives offer sustainable ways to be used as fine aggregates, reinforcements, and cement replacements. Besides, these also offer practicable internal curing and alternative shrinkage mitigation applications. Furthermore, these could be used in numerous multiple combinations with other materials to derive complementary benefits. Importantly, CMs and derivatives could significantly improve cost-effectiveness through mix design optimization choices, and their use in lightweight E-3DCP structures. Finally, recommendations are drawn as benchmarks for future research and development. Therefore, an increased yet optimized use of CMs and derivatives could lead to revolutionary applications of E-3DCP.