PHYSICAL, MECHANICAL AND CHEMICAL PROPERTIES OF NANOCELLULOSE FIBRE REINFORCED MORTAR

The paper presents an experimental investigation to evaluate the potential use of a water-based nanocellulose fibre derived from wood pulp sourced from sustainably managed forests in the applications of cementitious materials. The effect of the fibrillated cellulose fibre and its water-based solution on the physical, mechanical, shrinkage, and pore properties of OPC (ordinary Portland cement) mortar was investigated. Xrd and ft-ir analyses were performed to evaluate oxide composition, hydration products, bond interactions and functional groups present in the hydration products of the mortar samples reinforced with cellulose fibre. The shrinkage crack prevention provided by the cellulose fibre reinforcement under long-term drying conditions was also evaluated. Cellulose fibres were added to the mortar mixes in increments from 0.15% to 1.5% by weight of mortar. Results from the investigation reveal that the addition of cellulose fibre into the mortar mixes has a significant effect on the rheology of the matrix. The addition of cellulose fibre into the mortar matrix results in less than 10% increase or reduction in flexural and compressive strength at fibre contents which produce a workable mix. Drying shrinkage data for the mortar mixes after 28 days show that cellulose fibre in small amounts reduces the drying shrinkage as observed for mixes with fibre content up to 0.45%. The differential cumulative pore volume curves produced by a mercury intrusion porosimeter show that the cellulose fibres in the mortar matrix affect the large capillary pore volume for all the mortar mixes. All mixes exhibit bimodal pore size distribution profiles. A optimum dosage of 0.45% CF resulted in minimum drying shrinkage and no cracking of the mortar.