Performance of Fiber-Reinforced Self-Consolidating Concrete for Repair of Reinforced Concrete Beams

摘要

Fiber-reinforced self-consolidating concrete (FR-SCC) was investigated to assess its potential value as a repair material of reinforced concrete beams. A total of 10 repair mixtures were optimized to repair 10 full-scale beams. The mixtures included eight FR-SCC mixtures, one fiber-reinforced self-consolidating mortar, and a reference self-consolidating concrete (SCC) made without fibers. Four types of fiber reinforcement were employed: steel, two kinds of polypropylene, and hybrid fibers. Each fiber type was used at two volume contents of 0.3 and 0.5% for the FR-SCC mixtures and at 1.4% for the steel fibers in the mortar mixture. The beams were 3100 mm (122.05 in.) long, 250 mm (9.84 in.) wide, and 400 mm (15.75 in.) deep. The beams were cast using conventional vibrated concrete except for the lower 125 mm (4.92 in.) zone of the beam, representing a damaged area in the tension zone. After curing, the bottom layer was repaired using the self-consolidating mixtures. The beams were tested under four-point bending over a simply supported clear span of 2600 mm (102.36 in.). Test results indicated that the optimized self-consolidating repair mixtures can successfully restore the flexural capacity of the test beams, showing a great potential in repair and infrastructure rehabilitation. Key fresh and hardened properties of the repair fiber-reinforced self-consolidating mixtures were evaluated and presented in this paper.