Recent advancements and future trends in 3D concrete printing using waste materials

3D concrete printing (3DCP) is an innovative construction technique that enables the creation of complex and customized structures. This technology offers advantages such as reduced waste materials, faster construction times, and the ability to produce unique designs with intricate details. This article reviews the latest advancements in the 3DCP technology, its potential to transform the building and construction industry, and the latest developments in the 3DCP systems, methodologies, materials, and applications. The article concludes that several parameters and concrete mix proportions heavily influence the 3DCP process. Using waste materials as supplementary cementitious materials can significantly improve the 3D-printed concrete's rheology, but the excessive use can decrease the early strength. Lastly, using recycled sand in 3D printing can reduce the flexural stiffness and strength of the printed objects when loaded from different directions. The article also categorizes large-scale 3DCP technologies, highlighting the need to optimize printing ink for better economic and environmental outcomes using waste materials in 3DCP applications