Limestone Calcined Clay Cement for Three-Dimensional- Printed Engineered Cementitious Composites

The feasibility of three-dimensional (3D)-printable (3DP) engineered cementitious composites (ECC) has previously been demonstrated. However, the high carbon footprint of ordinary portland cement-based ECC remains a sustainability challenge. An emerging green limestone calcined clay cement was employed as an intrinsic rheology modifier Both fresh and hardened properties were investigated. The lower-carbon cement increased the viscosity and shape-retention ability compared to portland cement-based ECC, endowing the new composite with intrinsic printability. The compressive strength and split tensile strength exhibited anisotropy, depending on the loading direction relative to the layered geometry. Despite the negative impact of the progressive cavity pump on fiber dispersion, 3D-printable limestone calcined clay cement-based ECC retained a ductility of 3.0% at 28 days, showing promise in sustainable construction applications.