3D printable cellulose concrete: a review and pathway to future research

The construction industry is under enormous pressure to reduce carbon emissions, and cellulose fibres offer a sustainable and cost-effective approach to enhancing mechanical performance. This review examines the applications of cellulose fibres in 3D concrete printing (3DCP), with a focus on scalability, environmental benefits, and characterisation methods. The main contribution of cellulose fibres to cementitious matrix is their ability to refine microstructures, thereby improving flexural strength by up to 20% and CO 2 sequestration by 18.4%. However, the benefits of CO 2 sequestration are usually overestimated, and large-scale application faces challenges related to fibre variability and lack of standardisation. Research gaps are found in the understanding of anisotropy, fibre orientation, and pore morphology in 3D printed cellulose concrete. Advanced characterisation tools, particularly μCT combined with machine learning, present opportunities to address these challenges. This review identifies key areas for future investigation, including anisotropic behaviour, carbonation mechanisms, and design optimisation, aiming to advance 3DCP cellulose concrete as a viable material for sustainable construction and circular economy strategies. • Evaluates cellulose fibres in 3DCP, enhancing microstructural refinement and mechanical properties. • Analyses cellulose’s role in increasing CO 2 sequestration by 18.4% in alkali-activated slag. • Identifies anisotropic behaviour and pore morphology as critical research gaps in 3DCP cellulose concrete. • Recommends μCT with machine learning for precise analysis of fibre dispersion and porosity. • Proposes wastewater-derived cellulose to improve scalability and sustainability in urban 3DCP applications.