Effect of flow behavior and process-induced variations on shape stability of 3D printed elements – A review

Abstract Successful implementation of extrusion-based 3D printing (3DP) of concrete requires knowledge of material flow behavior during pumping and extrusion and its influence on shape stability of printed elements. Limited emphasis exists on flow behavior and process-induced variations in material properties (rheology and composition) during printing. This paper delineates the effect of flow behavior and process-induced variations on shape stability. A comprehensive review of material flow behavior during pumping and extrusion is discussed, and its influence on shape stability of 3DP elements is highlighted. The extent of shearing in print material is shown to govern process-induced variations during pumping and extrusion. During extrusion, the degree of filtration and consolidation plays a significant role on shape stability. Accurate assessment of process-induced changes in material properties is required to ensure steady and continuous flow of material during 3DP and secure proper shape stability of printed elements.