New Procedure to Evaluate the Post-Crack Behavior of Fiber-Reinforced Concrete

This study attempted to identify the challenges in testing and characterization of the post-crack behavior of structural fiber-reinforced concrete (FRC) for use in pavements. The benefits and challenges associated with three different FRC testing methods, ASTM C1550, C1399, and C1609 were discussed and compared. Two new parameters, post-crack toughness, and post-crack performance (PCP) index were proposed to characterize the post-crack behavior of FRC. These parameters are a function of the fibers’ contribution and are minimally influenced by the properties of the non-fiber ingredients of concrete such as aggregates, cement, and water. A laboratory study conducted on 10 different types of FRCs validated the applicability of the two proposed new parameters. Transportation agencies can use the PCP index to shortlist effective fibers and post-crack toughness to determine fiber dosage. The study found that fibers with irregular cross-section or geometry and high lateral stiffness provide a high post-crack contribution.