New study published on 3D printing presents opportunity to reuse concrete waste

With concrete waste generated by the construction industry invariably heading towards landfill, a new study published by the Journal of Cleaner Production has provided a comprehensive review of 3D printing concrete opportunities.

As the awareness of of transitioning to a circular economy gathers momentum, the opportunity to reuse concrete as a feedstock for 3D printing provides a compelling argument.

Construction waste is predicted to reach 2.2 billion tons by 2025, and with a majority of nations committing to 2050 net-zero carbon emissions, it’s a race to develop viable technology to assist this transition.

Research into sustainable cementitious mixtures has been a key focus within the construction industry for many years, and the mixtures typically include industrial wastes such as aluminosilicate (minerals composed of aluminium, silicon, and oxygen) materials that have been recovered from previous construction projects.

The concept of 3D printing for the construction industry was initially outlined in 2004, with a key development in 2011 by researchers at Loughborough University in the UK who developed 3D concrete printing. The process developed at Loughborough involves printing concrete layer-by-layer following a digital design. In the past few years, several projects worldwide have utilised this technology.

3D printed concrete must posses two properties: low viscosity (extrudability) and high yield stress (buildability), and the study further discussed the use of sustainable cementitious materials and other industrial wastes in 3D concrete printing.

Industrial wastes suitable for 3D printing investigated by the authors include fly ash, silica fume, blast furnace slag waste, limestone, quartz, mine tailings, and biomass ashes.

Finally, the authors have identified future perspectives and opportunities which will govern the commercial viability of 3D printed sustainable cementitious materials derived from industrial waste. The authors have stated that the paper is potentially useful for both industry and academia, and could serve as a reference document for policymakers and assist in the long-term attainment of the UN Sustainable Development Goals’ targets.

See: Science Direct