Effect of Fibre Treatment on the Physical and Mechanical Properties of Kenaf Fibre Reinforced Blended Cementitious Composites

Kenaf (Hibiscus Cannabinus L.) fibres are thermally and alkali treated to enhance the interfacial bond between the fibre-matrix, the mechanical properties of the fibre itself, the fibre-reinforced thermally activated alum sludge ash (AASA) and the nanosilica (NS) blended cementitious composites. The tensile strength of treated fibres increases by approximately 160% compared to untreated fibres after 72-h immersion in a 6% optimum concentration of mild sodium bicarbonate (NaHCO3). The surface characteristic with refined crystallinity are confirmed by morphology observation from a scanning electron microscope (SEM) and X-ray diffraction (XRD). The treated KF reinforced AASA and NS blended cementitious composite (KFRBCC) blended with 50% AASA, and 4% NS had optimum mechanical properties, with an increase of 42.1% in the compressive strength compared to that of the control. The results suggest that fibre treatment and the addition of blended pozzolan significantly improve the physical and mechanical properties of fibre reinforced cementitious material.