Performance criteria, environmental impact and cost assessment for 3D printable concrete mixtures

Extrusion-based concrete 3D printing is a promising technology and has the potential for being a sustainable construction solution by utilizing structural optimization and reduced material usage. However, studies focusing on the sustainability assessment of 3D printable concrete mixtures are not many. In the current study, a quantitative assessment of the environmental and economic impact of multiple 3D printable concrete mixtures for the production of one cubic meter volume is performed. 3D printable concrete mixtures made with (i) different binder systems and (ii) increasing aggregate content and modified gradation of the aggregate skeleton by adding natural and recycled coarse aggregates, satisfying a set of performance criteria, were evaluated. It was observed that the use of calcium sulfoaluminate-limestone binder systems has significantly lower global warming potential; however, the depletion of fossil resources indicator is much higher than compared to the Portland cement-based mixtures. Increasing the aggregate content decreases environmental impact; however, incorporating recycled and coarse aggregates do not significantly decrease the environmental impact at a lower replacement level. Also, it was found that the contribution of the chemical admixtures to the total material cost is significantly higher in the case of 3D printbale concrete mixtures in comparison to the conventional mould cast mixtures. The study provides insights into the environmental and economic impact of extrusion-based concrete 3D printing materials satisfying the same functional requirements