Fresh and Mechanical Properties of the Ultra-High-Performance Concrete with Cellulose Nanofibers

Water-sensitive cellulose significantly impacts the performance of the ultra-high-performance concrete (UHPC), leading to variations in its fresh and mechanical properties of fresh and hardened concrete materials. In this study, the cellulose nanofibers, a more environmentally friendly class of nanomaterials, are introduced into UHPC. The rheological and mechanical properties of UHPC are investigated, including viscosity, yield stress and compressive strength. The results reveal significant effect of cellulose nanofibers on the properties of UHPC in terms of material performance and sustainability. Advanced characterization techniques, including isothermal calorimetry, thermogravimetric analysis (TGA), and X-ray diffraction (XRD) are employed to study the effect of cellulose nanofibers on the hydration process of UHPC. Furthermore, microstructural characterization techniques, such as scanning electron microscopy (SEM) are utilized to investigate the impact of cellulose nanofibers on the performance of UHPC from micro-scale level of the materials.