The effects of sodium (N) silicate, potassium (K) silicate, and silane (Si) treatment levels on newspaper and unbleached kraft fibres for enhancing selected mechanical properties of wood fibre-cement composites was studied and compared to untreated wood fibre-cement composites. Both wood fibre types were treated with selected aqueous solution strengths, air dried, and mixed with water and cement. The bending and compression properties of the specimens were determined after 28 days of hydration. The results indicated that chemical treatment of the wood fibres enhanced some of the mechanical properties, depending on the treatment used and wood fibre type. All three chemical treatments of newspaper fibre enhanced the normalised toughness values compared to untreated newspaper fibre-cement composites. Higher treatment levels using N silicate with newspaper fibre improved the compressive strength and bending modulus of the composites compared to untreated composites. Kraft fibre treated with all three chemicals enhanced the compressive strength, bending modulus and bending strength compared to untreated composites. However, only silane-treated kraft fibre improved the normalised toughness values compared to untreated composites. The results showed that certain chemical treatments react better with different wood fibre types, resulting in selected mechanical property enhancements. 25 refs.
Primary author(s): Pehanich J L; Blankenhorn P R; Silsbee M R