GGBFS-Cement 3D-Printed Concrete Rheology

3D printing is an additive manufacturing technique used in modern construction. Unlike conventional concrete, which requires formwork, 3D-printed concrete is a pseudo-solid material that allows for layer extrusion additive manufacturing techniques without the need for formwork. For successful 3D printing, the concrete must possess several rheological characteristics, such as global stability, layer stability, pumpability, printability, and buildability, to ensure continuous extrusion and stable printing. These characteristics map to time-evolving rheological material parameters, such as static yield stress, dynamic yield stress, pseudoplasticity, and thixotropy. In general, pumpability is governed by the static shear stress transition, printability by the Bingham viscosity, layer stability by thixotropy, and buildability by the time evolution of static yield stress. While the existing literature focuses on the rheology of both cement and polymer-based 3D-printed concrete, there remains a gap in exploring the rheological behavior of low-carbon alternatives of 3D-printed concrete. This work aims to address this gap by studying the impact of partially replacing cement in 3D-printed concrete with Ground Granulated Blast Furnace Slag (GGBFS) on the rheological parameters of 3D-printed concrete. In addition, this work presents an estimation of the reduction in carbon footprint due to this GGBFS partial replacement of cement, offering a low-carbon alternative for 3D-printed construction.