Fundamentals of 3D printing of cementitious composites: fresh property, machine design, and modeling perspectives

Additive manufacturing, or three-dimensional (3D) printing of cementitious composites, is a cutting-edge digital technology that is rapidly advancing in the construction industry. This sophisticated technology has several advantages over traditional construction methods, such as reduced construction time, cost, waste generation, labor dependency, and increased design flexibility. Specifically for the printing of cementitious mix, certain fundamental aspects must be taken into consideration related to fresh property as well as machine design. This chapter delves into all the fundamental but crucial printability aspects in the design of 3D printable cementitious composites. The fresh property parameters, including flowability, buildability, extrudability, pumpability, and open time, along with some of the critical machine parameters, have been systematically discussed. The challenges associated with adaptive nozzle technology for 3D printing cement-based composites have also been succinctly reviewed, along with the solutions to address these challenges. Additionally, an overview of current research in numerical modeling of 3D-printed cementitious composites is provided. Finally, the chapter discusses current challenges and offers recommendations for future work to facilitate the widespread adoption of 3D printing technology in construction.