Basic fresh-state properties of extrusion-based 3D printed concrete

This paper aims at reviewing the basic properties of fresh-state extrusion-based three-dimensional (3D) printed concrete in order to explain the specific properties of this construction technology. The review was conducted using the bottom-up approach. The most recent literature in the field of extrusion-based concrete printing was used as a starting point, while additional papers were included through screening the references of relevant papers. Based on the inclusion criteria, review and experimental papers containing data on fresh-state 3D printed concrete properties were included, as well as materials used for 3D printing, since their properties directly affect the fresh-state properties of concrete mixture. Papers concerning data only on hardened properties were excluded. Reviewed properties are: technological properties (pump ability and flow ability) and printability properties(extrudability, print quality and buildability).