This paper presents the results of an experimental investigation to determine the flexural fatigue strength of concrete reinforced with three different concentrations of fibrillated polypropylene fibers. The properties and the performance of fresh and hardened concretes with and without fibers are compared. The test program included the evaluation of 1) flexural fatigue strength and endurance limit; 2) hardened concrete properties, such as compressive strength, static modulus, pulse velocity, modulus of rupture, and toughness indexes;and 3) fresh concrete properties, including slump, vebe time, inverted cone time, air content, and concrete temperature. The test results indicated an appreciable increase in post-crack energy absorption capacity and ductility due to the addition of fibers. When compared with corresponding plain concrete, the flexural fatigue strength and the endurance limit (for 2 million cycles) significantly increased. The static flexural strength increased after being subjected to fatigue loading.
Abstract