Effect of Cellulose Nanofibers on the Compressive Strength Enhancement of Cement Pastes at Early Ages

Abstract

This study investigated the effect of cellulose nanofibers (CNFs) on the early-age compressive strength development of cement pastes. CNFs were incorporated at concentrations of 0.05%, 0.1%, and 0.15% by weight of cement using a combined ultrasonication and magnetic stirring technique to ensure proper dispersion. The impact was evaluated at 3 and 7 days of curing, with microstructural analysis conducted using scanning electron microscopy (SEM). Results showed that all CNF-modified mixtures exhibited enhanced compressive strength compared to the control, with 0.1% CNF concentration showing optimal performance. At 3 days, improvements of up to 49.7% were achieved with 0.05% CNFs, while at 7 days, the 0.1% CNF mixture demonstrated the highest strength enhancement of 69.6%. The strength development analysis revealed significant improvements in hydration rates, with CNF-modified mixtures showing up to 265.5% higher strength gains compared to the control. SEM observations confirmed the formation of a well-integrated fibrous network and enhanced matrix densification in CNF-modified samples.