Review of Emerging Additive Manufacturing Technologies in 3D Printing of Cementitious Materials in the Construction Industry

Abstract

Additive manufacturing is a fabrication technology that is rapidly revolutionizing the manufacturing and construction sectors. In this paper, a review of various prototyping technologies for printing cementitious materials and selected 3D printing techniques are presented in detail. Benchmark examples are provided to compare three well-known printing techniques; inkjet printing (binder jetting), selected laser sintering (SLS), and extrusion printing (extrusion based process). A comprehensive search in the literature was conducted to identify various mix designs that could be employed when printing cementitious materials. Aspects of concrete mix design are described, and some new experiments are conducted to analyse the printability of new mixes by the authors. Future research in the area of the rheology of cementitious materials and its relationship with the structural performance of finished concretes are highlighted.

Extrusion-Based Additive Manufacturing of Concrete Products: Revolutionizing and Remodeling the Construction Industry

“…A walls additive manufacturing approach is more sophisticated and faster than the Contour Crafting process, as the printing apparatus allows one to develop the pre-designed building directly without the need for formworks, then through a single-step deposition process [18]. Typical examples of construction processes based on a walls additive manufacturing approach are ICON technology and WASP technology.…”

“…To minimize print nozzle obstructions and ensure proper mix fluidity, many researchers focused their studies on the design of fine particles-based mixtures (printable mortars) suitable with high-resolution print nozzles (up to 1 cm diameter). The optimal size of fine aggregates provides values of no more than 300 µm [18,27]. However, some of these mixtures are also characterized by a certain percentage of coarse sand (up to 2 mm size) [18,26].…”

“…The optimal size of fine aggregates provides values of no more than 300 µm [18,27]. However, some of these mixtures are also characterized by a certain percentage of coarse sand (up to 2 mm size) [18,26]. This replacement is implemented to improve the strength of the mortar and reduce the shrinkage crack in the printed objects [18].…”

“…However, some of these mixtures are also characterized by a certain percentage of coarse sand (up to 2 mm size) [18,26]. This replacement is implemented to improve the strength of the mortar and reduce the shrinkage crack in the printed objects [18]. Several printing technologies use cement mix based on coarse aggregates (Ø > 4mm) [18,28].…”

“…This replacement is implemented to improve the strength of the mortar and reduce the shrinkage crack in the printed objects [18]. Several printing technologies use cement mix based on coarse aggregates (Ø > 4mm) [18,28]. The presence of the coarse fraction improves the mechanical properties of the material compared to the printable mortars but requires the use of larger print nozzles (approximately 2.5 cm diameter).…”