Hydration Characteristics of 3D Particle Bed Printed Cementitious Specimens

This study investigates the hydration process of cement in 3D-printed specimens, aiming to understand the unique characteristics and challenges associated with this innovative construction method.
A series of cementitious specimens containing various combinations of aggregates and binders were fabricated using a self-constructed, laboratory-scale particle bed printing system. The proportion of unhydrated cement in the particle bed after curing for 21 days was assessed by using X-ray diffraction together with Rietveld refinement.
Results indicate that the 3D-printed specimens exhibit distinctive hydration patterns compared to conventionally cast counterparts. The layer-wise deposition of activator liquid in the selective cement activation process introduces variations in water availability and diffusion rates influencing the hydration process across different regions of the specimen, confirmed by scanning electron microscopy.