Bond of Deformed Bars to Concrete: Effects of Specialty Cellulose Fibers

Processed cellulose fibers provide high levels of elastic modulus, tensile strength, bond strength to concrete, and durability. Their fine diameter also yields a close fiber spacing at relatively low fiber volume fractions, and allows them to establish a strong presence in the interface zones between reinforcing bars and concrete. Specialty cellulose fibers have been recently developed for convenient dispersion into normal concrete mixtures using conventional mixing procedures. This research project investigated the effect to specialty cellulose fibers at volume fractions of about 0.1% on the strength and toughness of bond between deformed bars and concrete. The experimental results were indicative of the effectiveness of specialty cellulose fibers in enhancing bond strength and toughness. The positive impact of specialty cellulose fibers on bond strength was more pronounced as a fiber volume fractions increased to the upper limit of 0.18% considered in this investigation.