Three-Dimensional Printability of White Portland Cement Containing Cenospheres

To reduce construction costs and carbon footprint while maintaining durability, recent research has focused on incorporating supplementary cementitious materials (SCMs) (for example, blast-furnace slag, fly ash, and natural pozzolans) and microaggregates (for example, cenospheres) in the primary cement matrix. Because of their low density and porous nature, these supplementary materials are capable of imparting some desirable properties on structures, such as light weight and reduced thermal conductivity. In this context, this work investigates the rheology, three-dimensional (3D) printability, and mechanical and thermal properties of white portland cement (WPC) containing 25 wt.% cenospheres in comparison with pure WPC. While both compositions were tuned with suitable additives to enhance their 3D printability, significant differences were observed in their rheological properties. Rheological tests revealed that the addition of cenospheres improved the paste extrudability while retaining good buildability. For both mixtures, the same types of structures were 3D-printed and compared in terms of morphology, microstructure, compressive strength, and thermal conductivity. This study paves the way toward the development of 3D-printable WPC-based mixtures with improved structural and thermal properties for modern construction needs.