Flexural behavior of PVA and PP fiber-reinforced concrete under cyclic loading

The behavior of structural elements subjected to cyclic loadings can be improved by fiber-reinforced concretes (FRC). Some improved properties are crack opening control, damage propagation control, and reduced stiffness loss during the service life. Therefore, FRC structures can withstand thousands or millions of loading cycles without losing structural integrity, even after cracking. This paper evaluates both stiffness and damage propagation behaviors and the development of cracks on Polyvinyl Alcohol (PVA) FRC, Polypropylene (PP) FRC, and plain concrete specimens, comparing the materials' behavior under three-point bending cyclic and quasi-static tests. The results of quasi-static tests indicate the addition of PVA fibers increases ductility and toughness, as observed for PP macro fibers. According to the cyclic tests, the fibers contribute to improving stiffness maintenance, reducing crack propagation, hence, damage to the material over the cycles. A comparison between PVA-FRC and PP-FRC revealed PVA specimens showed less stiffness reduction and lower damage propagation through the cycles, implying a smaller CMOD variation.