Abstract: Repair mortar and methods of preparing repair mortar are provided. The repair mortar comprise a cement binder, fine aggregate and cellulose fibrils. In some embodiments, the cellulose fibrils are dispersed uniformly throughout the repair mortar. In some embodiments, the cellulose fibrils comprise nanofibrillated cellulose and/or microfibrillated cellulose. In some embodiments, the cellulose fibrils comprise an aspect ratio of between about 20 to about 500. The methods comprise mixing a cement binder, fine aggregate with water/chemical admixture to provide a cementitious material of good consistency, mixing cellulose fibrils with water to provide a cellulose fibril slurry, and mixing the cellulose fibril slurry with the workable cementitious material. In some embodiments, the cellulose fibrils are dispersed uniformly throughout the workable cementitious material.

Abstract: A process for preparing a cellulosic pulp for use as an internal curing agent for a hydraulic cement-based composite material is disclosed. The process involves selecting a degree of refining of the cellulosic pulp to cause sufficient fibrillation to provide a change in water retention capacity for the cellulosic pulp while simultaneously limiting a decrease in dispersability within a mixture for forming the composite material due to excess fibrillation. The process also involves controlling refining of the cellulosic pulp using the selected degree of refinement to produce the cellulosic pulp internal curing agent.