Properties of nanofibre reinforced cement composites

Objective: This paper investigates the potential and limitations of using relatively low volume fractions of cellulose nanofibre as reinforcement in cement pastes. Materials and methods: General use limestone (GUL) cement and cellulose nanofibre gel suspension were used in the preparation of cement paste. Mixture conductivity, hydration, flexural strength, energy absorption and fibre dispersion in hardened cement matrix were evaluated. Results: Cellulose nanofibre reduced the conductivity and the early age hydration of mixtures. However, at 28days, the cumulative heat of hydration and the degree of hydration of cement pastes containing cellulose nanofibre were higher than those of the unreinforced reference mixture. Optimum mechanical properties were observed for paste containing 0.1% nanofibre. The decrease in mechanical properties at higher nanofibre content is as a result of fibre agglomeration. In comparison to the reference paste, the flexural strength and energy absorption of 0.1% nanofibre paste increased by approximately 106% and 184%, respectively.