Mechanical Properties of Hybrid Synthetic Fiber Reinforced Self- Consolidating Concrete

This study investigates the fresh and mechanical properties of self-consolidating concrete (SCC) reinforced by synthetic polymer fibers. The influence of hybrid fiber reinforcement on these properties and the effect of fiber manufacturing method are reported. Eight mixtures on which seven are reinforced with a fiber volume fraction of 1% with varied percent of macro and microfibers are investigated. The concrete density, filling ability, passing ability, segregation, compressive strength, and splitting tensile strength are recorded. The test results showed that the higher the macro fibers in the mixture, the denser the concrete and the less macro fibers in the hybridization, the higher the slump flow. For mixtures with hybrid fibers, the compressive strength decreases with increasing microfiber percent. The combination of macro and microfibers achieved higher tensile strength than the single fiber mixture. The research also found that when compared with concrete reinforced with monofilament polypropylene fibers, concrete reinforced with a collated fibrillated fiber is less flowable with less passing ability, lower compressive and splitting tensile strength. Multivariable regression was also conducted for all investigated properties to optimize the volume fraction for each fiber type