Rheology and printability of Portland cement based materials: a review

Three-dimensional (3D) concrete printing (3DCP) is one of the digital construction techniques that demands the fulfilment of particular material properties. One of the most important requirements for 3DCP is the material's rheology. This article provides a comprehensive analysis of the rheology of Portland cement-based materials used in extrusion-based 3DCP. The first sections of the article focused on the influence of mix design on the rheology required for 3DCP in both fibre reinforced and non-fibre reinforced mixtures, followed by the role of various chemical admixtures in tailoring the time dependent rheology. The research points out the lack of rheology benchmarking, implying a strong need for novel or standard printable mix designs that use sustainable materials to improve the structural build-up of mixtures. The review also shows a strong need for active rheology control of cementitious materials for large scale printing application.