Printable concrete with multi-source recycled aggregates: particle packing design, rheological behavior, and 3D printing validation

Abstract Concrete 3D printing faces challenges due to the global shortage of natural sand. In this context, construction and demolition waste, scallop shell waste, and recycled PET offer sustainable alternatives. This study develops and validates a concrete mix design methodology incorporating these recycled aggregates, using the Funk-Dinger model to optimize particle size distribution for 3D printing. A comprehensive experimental campaign was conducted to characterize the physical properties of