Nano-modification in digital manufacturing of cementitious composites

Abstract

Remarkable attention from both academia and industry has been attracted to extrusion-based 3D concrete printing (3DCP) during the last decade. Many companies in the Netherlands, e.g., Royal BAM Group, CyBe, Twente Additive Manufacturing, and Bruil, are attempting to implement this technology in practice. 3DCP is the focused digital concrete manufacturing technique in this study. The development of printable cementitious composites is possibly the most critical aspect in 3DCP. Compared to mold-cast concrete process, several essential material parameters need to be controlled in 3DCP process, i.e., pumpability, extrudability, buildability, and others. Conventional materials technology appears to have limited resources to offer for further enhancing the capabilities of 3D printing. Therefore, there is a dire need for adopting non-conventional materials solutions for which nanomaterials can play a vital role. Controlling the rheology is the key to successful 3DCP, as achieving dimensional stability and the minimum required mechanical properties in green state are the main challenges. Furthermore, achieving a required strength development rate and enabling smart monitoring of the 3DCP are the other goals that are desired in designing such materials. Recent research shows that successful modification of cementitious materials can be achieved by incorporating nanomaterials in the materials design for the enhanced fresh and hardened state properties. In this chapter, a summary of these developments is compiled in the light of potential applications, safety issues, and technological challenges.