Post-Crack Flexural and Joint Performance Behaviors of Fiber-Reinforced Concrete for Pavements

This study investigated the influence of fiber properties on the post-crack flexural and joint performance behaviors of fiber-reinforced concrete (FRC) for thin concrete overlays. The study included a literature review, an online survey, and laboratory testing. It was found that the majority (almost 93%) of the FRC overlays in the United States of America were constructed with synthetic macro fibers. In the laboratory study, a total of 46 different FRC mixes were prepared with 11 different types of fibers. Fiber dosage, stiffness, and geometry significantly influenced the residual strength ratio (RSR) and residual strength (RS). In general, stiffer fibers with geometry like embossed, twisted, and crimped shapes showed higher post-crack flexural strength on average than the low-stiffness straight synthetic fibers. From the joint performance testing, it was found that fibers can improve the load transfer efficiency (LTE). A nomogram was developed so that agencies can select fiber dosage and type based on the target values of RSR, RS, and/or LTE.