Portland cement concrete used for rapid pavement repair applications must meet minimum standards of strength and durability before the pavement can be opened to traffic. Concrete mixtures for such applications typically require a high cement content, low water cement ratio, and a high dosage of accelerating admixtures. The direct experience of state transportation departments, including the Michigan department of transportation (MDOT) has been that high-early strength concrete mixtures (HESC) exhibit sound strength properties but, fall short in long-term performance, resulting in the deterioration of the pavement. SEM graphs have shown excessive micro-cracking in the cement matrix due to high shrinkage strains as a result of the early heat of hydration. The shrinkage cracking is probably increased due to the rapid gain in elastic modulus (increases restrained shrinkage) and thermal stresses and shrinkage strains (due to high cement content and low water-cement ratio). The rapid strength gain influences the morphology and spacial distribution of hydration products, the less uniform distribution of the hydration products leading to poor permeability characteristics and exposing the cement matrix to inadequate long-term performance characteristics.

With these short comings associated with HESC mixtures it is proposed that processed cellulose fibers be introduced into the mixture to reinforce the cement matrix during its "green" state. It is hypothesized that by the addition of fibers, the cement content can be reduced by 20-25%, thereby elevating the water-cement ratio and reducing the heat of hydration. The slower rate of hydration will allow for an improved distribution of hydration products and subsequently improving permeability characteristics.