Sustainable Additive Manufacturing—How the Composition of the Cementitious Mix Influences Its Fresh Properties

This chapter investigates the critical factors influencing the fresh properties of cementitious mixes used in additive manufacturing, with a focus on 3D printing technology. The study examines how the composition of concrete mixes affects their yield stress, flow ability, and viscosity, which are essential for successful extrusion and layering in 3D printing. Three different concrete mixes were analyzed, each with varying proportions of cement, fly ash, and granite powder, to observe their rheological characteristics and performance over time. The chapter provides a comprehensive overview of laboratory tests, including slump flow, vane shear, and slug tests, to determine the yield stress and consistency of the mixtures. The results highlight the significant impact of granite powder on the density and yield stress of the concrete mixes, demonstrating that higher granite powder content leads to increased yield stress and reduced slump spread. The comparative analysis of the vane shear and slug test methods reveals differences in yield stress calculations, underscoring the importance of selecting the appropriate test method for evaluating the rheological properties of concrete mixes. The findings offer valuable insights into optimizing concrete mixes for additive manufacturing, paving the way for more efficient and cost-effective construction practices.