Characterization and Influence of Nanofiber Flours of Wood Modified on Fresh State Properties of Cement Based Mortars

摘要

Nanofibrillated wood fiber was used as fillers in the partial cement matrix replacing the cement to a content of up to 2% by weight of cement. The nanofibrillated effect of wood fibers on porosity, thermal properties and compressive strength was studied. The results obtained showed an improvement in compressive strength of more than 40% with 1% by weight of wood fiber nanofibrillate. The addition of nanofibrillated wood fiber shows a good pore reduction, and the best result was obtained with emulsion of a mixture incorporating 1% by weight of wood fiber nanofibrillate in the presence of an anionic surfactant (SDBS). Thermal conductivity measurements and thermal expansion coefficient, compared to nanofibrillated wood fiber reinforced cement pastes, showed the reinforcing efficiency of cellulose fiber nanofibrillate. The degree of hydration of the cement increased with nanofibrillated wood fibers. This property has been confirmed by Fourier transform infrared spectroscopy. These analyzes revealed that the presence of nanofibrillated wood fibers generates and promotes the hydration of the cement, producing more portlandite and calcium silicate gel, which influences the compressive strength which gives a strong improvement.