Uniaxial tensile behavior of concrete reinforced with randomly distributed short fibers

A study was made of the behavior of concrete reinforced with randomly distributed short fibers under uniaxial tension. Five kinds of fibers were used to prepare the fiber reinforced concrete (FRC) specimens for the uniaxial tension test. These included two kinds of steel fibers, two kinds of PVA fibers and one kind of polypropylene fiber. Fiber volume fraction varied from two to six percent in most cases. The matrices were normal strength concrete and/or admixture modified concrete. Plain concrete specimens were also prepared as a reference for the purpose of comparison. The adaptive control test method was used in the experimental study to obtain complete stress-deformation responses for both plain concrete and fiber reinforced concrete. Both "strain softening" and "strain hardening" behavior was observed in the experiment and it seemed that a transition point did exist for the composites. It was concluded that strain hardening and multiple cracking responses can be achieved for concrete incorporating short fibers when the parameters are carefully selected.