Cellulose Nanofibrils for Concrete Shrinkage Reduction

Cracking in concrete structures, particularly under cold-weather conditions, significantly compromises durability and long-term performance. Early-age shrinkage is a primary contributor to crack formation, leading to increased maintenance demands and reduced service life. This study investigates the incorporation of Cellulose Nanofibrils (CNF) as a sustainable additive to mitigate shrinkage and enhance mechanical properties in both cement paste and concrete. Specimens were prepared with CNF dosages of 0%, 0.1%, 0.2%, 0.3%, 0.4%, and 0.5% by weight of cement. In cement paste, CNF addition up to 0.3% improved compressive and flexural strength by approximately 25% and 34%, respectively, and reduced shrinkage by 21%. In concrete, CNF increased compressive strength by 16%, flexural strength by 28%, and reduced shrinkage by 17%. The highest performance was observed at 0.3% CNF, while higher dosages resulted in diminished gains, likely due to fiber agglomeration and dispersion challenges. The results highlight the potential of CNF to enhance the mechanical and durability properties of cement-based materials, offering a promising approach for developing more crack-resistant and sustainable concrete, particularly suited for cold-climate infrastructure applications.