Mixture Design and Testing of Fiber-Reinforced Self-Consolidating Concrete

An extensive testing program was undertaken to evaluate the applicability of a mixture-proportioning method proposed for shrinkage control in fiber-reinforced concrete (FRC) in proportioning fiber-reinforced self-consolidating concrete (FR-SCC). The study also proposed test methods to evaluate workability of FR-SCC. The investigated fibers included polypropylene, steel, and hybrid fibers of different properties with fiber lengths of 5 to 50 mm. Fiber volume Vf ranged between 0.25% and 0.75%. The study also aimed to determine the impact of fiber type and addition on key properties of the fresh and hardened concrete. Hardened properties included compressive, splitting tensile, and average residual strengths. A superworkable concrete requiring low consolidation energy can still be produced with a Vf of 0.75% when a viscosity-modifying admixture is incorporated to prevent segregation and blockage. For the tested fiber types, the average residual strength (ARS) in flexure is shown to increase with Vf. Steel fibers exhibited the highest ARS value.