3D-printed multi-functional foamed concrete building components: Material properties, component design, and 3D printing application

The use of multi-density foamed concretes (FCs) to produce multi-functional building components by 3D Concrete Printing (3DCP) is investigated. The use of medium-density 3D-printed foamed concrete (3DPFC_800), primarily serving a load-bearing role, and ultra-lightweight foamed concrete (ULFC_300), as thermal insulation material poured in the voids defined by the former, is proposed. This enables meeting diverse performance requirements within a single cementitious matrix, eliminating the need for multiple materials. The main properties of the proposed mixes are investigated. The compressive strength and thermal conductivity are equal to 7.04 MPa and 0.205 W/mK, and 1.43 MPa and 0.072 W/mK for 3DPFC_800 and ULFC_300, respectively. A successful 2Dprinting test validates the suitability of 3DPFC_800 for 3DCP, and a robotic arm is employed for 3DCP tests. The proposed application allows for further knowledge on the use of FC in 3DCP and the identification of some issues and challenges that still need to be addressed.