Properties of Nanomodified Fiber-Reinforced Cementitious Composites

Abstract

This paper presents the development of nanomodified fiber-reinforced cementitious composite (FRCC) mixtures. A total of seven mixtures were prepared using general use cement and a constant dosage of slag (40% replacement by mass of the base binder). Also, nanosilica was incorporated in six mixtures at a dosage of 6% by mass of the base binder, whereas one mixture was without nanosilica as a reference. Basalt fiber (BF) pellets (made of basalt fibers encapsulated by polyamide resin) were used to produce BFRCC. Three mixtures had BF pellets with different lengths (25 mm, 36 mm, or both), whereas two mixtures incorporated BF pellets and polypropylene fibers. The performance of the cementitious composites was evaluated in terms of compressive and flexural strengths and toughness. In addition, the bond strength of glass fiber-reinforced polymer (GFRP) bars embedded in either the cementitious composites or normal-strength concrete was determined. Test results revealed that adding 2.5% by volume of 36-mm-long BF pellets to the mixture achieved the best performance. This BFRCC favorably showed high residual flexural strength and ductility compared to those of other mixtures. Furthermore, it achieved better bond strength to GFRP bars compared to both the nanomodified mixture without fibers and normal strength concrete.