Eco-Friendly 3D-Printed Concrete Made with Waste and Organic Artificial Aggregates

In this research, the results of an experimental study on the use of three alternative components for creating artificial aggregates (AAs) (granules) and their usage in 3D-printed concrete (3DPC) are examined. This study combines AAs made from organic components like hemp shives (HSs), pyrolyzed coal (charcoal), waste/municipal solid waste incinerator bottom slag (BS), and a mix of a reference 3DPC with the aforementioned AAs. Particularly, to enhance these properties to make low-carbon 3DPC, in this research, the potential of using AAs as lightweight aggregates was increased to 14% in terms of the mass of the concrete. Each mix was tested in terms of its printability via a preliminary test in a 3D printing laboratory. For an additional comparison with the aforementioned cases, 3DPC was mixed with unprocessed hemp shives, charcoal, and BS. Furthermore, their strength was measured at 28 days, and lastly, their durability parameters and shrinkage were experimentally investigated. Cross-sections of the fragments were studied under a scanning electron microscope. In this study, we achieved improvements in the mechanical properties of AAs for their development and implementation as an innovative way to reduce carbon in 3DPC.