Aligned kraft pulp fiber sheets for reinforcing mortar

In this research program, aligned pulp fiber sheets were used as reinforcement in cement-based matrices. Flexural testing results validate this reinforcement strategy by demonstrating that: (1) fiber sheet alignment does significantly affect mechanical behavior, indicating that fiber alignment is achieved by the production process, and (2) aligned fiber sheet composite exhibited significantly greater toughness than equivalent volumes of distributed fibers. Additional results indicate that the addition of the wet-strength additive Kymene facilitates the handling of fiber sheets, but has no effect on mechanical performance. Addition of fly ash to the fiber sheets also had no effect on composite behavior. Use of fibrillated (beaten) fibers and the introduction of perforations to the fiber sheets appeared to have no effect on flexural strength, while generally decreasing composite toughness. Increasing the fiber sheet basis weight (thickness) produced increases in toughness, with negligible changes in flexural strength. Reinforcement with multiple fiber sheets (total basis weight increasing) was shown to increase toughness, while layering with total basis weight remaining constant improved strength, but reduced toughness.