Surface modification on dispersion and enhancement of PVA fibers in fiber-reinforced cementitious composites

Abstract

AbstractIn this paper, non-ionic polyoxyethylene ether was used to modify the surface of poly(vinyl alcohol) (PVA) fibers and to improve their dispersion in cement mortar. The results showed that surface modification could apparently improve the dispersion of PVA fibers in cement mortar by weakening the original intermolecular hydrogen bonds between the adjacent hydroxyl groups on the surface of PVA fibers and increasing the formation of hydrogen bonds between PVA fibers and cement mortar. After modification, the advancing contact angle and the receding contact angle of the fibers were respectively reduced from 44.2° to 34.7° and from 38.8° to 33.1°, and the dispersion coefficient of the fibers was increased from 0.85 to 0.95. Owing to the improved interactions between modified PVA fibers and cement mortar and to the good dispersion of the fibers in the matrix, the fibers had a superior energy absorption capacity and showed a ductile fracture, leading to higher flexural strength, bending modulus and toughness of fiber-reinforced cementitious composites.