The Minnesota Department of Transportation (MnDOT) recently completed a study that used performance-engineered mixture (PEM) testing techniques to better understand fiber-reinforced concrete (FRC) and the parameters that indicate a high-performing paving mix. According to MnDOT, the study aimed to “identify PEM target specifications for FRC mixtures to provide for durable and long-lasting pavement.” Using a Super Air Meter (SAM) test, a box test and a Vibrating Kelly ball (V-Kelly) test, researchers established how adding fibers to paving mixes affects key characteristics and what special treatments FRC mixes require to optimize workability and performance. These results are especially important for paving mixes used in concrete overlays, as the structural capacity added by using fibers allows engineers and contractors to deliver higher-performing overlays using less material. You can read the summary of this study, courtesy of Crossroads, and the full report here.