Mechanical and Cracking Behavior of Concrete Beams Reinforced with Steel Bars and Short Fibers

It is well known that fibers embedded in a cementitious matrix enhance its toughness, increase its performance in tension and act as crack arrestors. While the interaction between fibers and concrete, as well as their effect on cracking, have been extensively investigated, the interaction between fibers and rebars in a R/C member is still open to investigation. In fact, a consolidated model to predict crack width in structural members embedding fibers can hardly be found in the literature; hence, further experimental efforts are needed to better understand the fiber-reinforcement interaction. Furthermore, the results found in the literature on Fiber-Reinforced Concrete mainly refer to steel fibers, while the effect of other fibers on concrete cracking and on R/C mechanics is a topic still requiring dedicated research efforts. In this research project, an experimental study on the effect that steel and polyester fibers have on the mechanical and cracking behavior of ordinary reinforced-concrete beams, is presented. The objective is to investigate the role that fiber amount, geometry and type have on the cracking behavior of the beams in terms of crack width and spacing.