The Effect of Crystalline Nanocellulose on the Rheology, Hydration of Cement Pastes, and Buildability of 3D-Printed Concrete (2025-09)¶

This study investigated the use of crystalline nanocellulose (CNC) in cementitious materials to enhance their performance in advanced construction techniques, particularly 3D printing. The research focused on the rheological behavior and early-age performance of cement pastes with varying CNC contents (0.015, 0.050, 0.100, 0.250, and 0.500 wt%). The study evaluated key properties such as yield stress, viscosity, structuring rate, heat flow, and mineralogical composition, using rotation rheometry, isothermal calorimetry, X-ray diffraction, and thermogravimetric analysis. The study also conducted 3D printing tests to evaluate the buildability of CNC-modified mixtures, establishing a direct link between the fresh-state properties and the performance of 3D concrete printing. The findings revealed that CNC addition up to 0.100 wt% moderately improved paste fluidity. However, higher CNC contents significantly increased yield stress and structuring rate, especially when combined with superplasticizer (SP) or sonicated CNC. These changes were beneficial for 3D printing applications, where increased yield stress and structuring helped build layers effectively without compromising pumpability. Additionally, CNC delayed cement hydration for up to 22 hours. The results suggest that CNC has the potential to optimize cementitious materials, improving their performance in innovative construction processes such as 3D concrete printing. This research contributes to the growing understanding of nanocellulose’s role in controlling the properties of fresh-state cementitious materials for advanced applications.