Mechanical properties of slurry infiltrated fiber concrete produced with waste steel fibers

The paper presents the results of an experimental study in which steel fibers recovered from scrap tires were used to produce slurry infiltrated fiber concrete (SIFCON). The waste steel fibers used in the study can be considered as hybrid fibers in terms of geometrical characteristics. They were balled up and their lengths were very long compared to commercially available fibers. The fibers were preplaced into molds, and then infiltrated by flowable cement slurry which has a low water/cement ratio. Mixtures with different fiber contents were cast. A plain mixture without fibers was also prepared for reference. Compressive strength, splitting tensile strength and flexural strength of the mixtures were determined. Load deflection curves including the post-peak responses were also obtained. Test results indicate that flexural strength, residual strength and toughness of the specimens increased depending on the fiber content. The mechanical properties and relative costs of the mixtures were used in a multi-objective simultaneous optimization procedure. Results from a previous study were also included in this procedure. The test results confirmed that waste steel fibers recovered from tires can be successfully used for SIFCON production.