Effect of Warm Mix Technologies and Testing Protocol on Moisture Susceptibility of Asphalt Mixtures

摘要

Moisture susceptibility of asphalt mixtures is a commonly addressed concern in mixture designs. As the industry shifts toward the use of warm mix asphalt (WMA) technology from the traditional hot mix asphalt (HMA) there has been increased concern regarding the performance of WMA technology in regards to moisture susceptibility. This concern is primarily driven by the decrease in required production temperatures of the asphalt mixtures which may result in aggregates that have not been dried thoroughly prior to being coated with asphalt binder. To assess this concern, 87 mixtures were evaluated for their resistance to moisture damage using the most common laboratory test for assessing such damage: AASHTO T 283. As a result of this study, it was determined that there was no statistical difference between field compacted specimens versus laboratory reheated specimens for tensile strength ratio (TSR). WMA consistently showed statistically lower TSR values compared to HMA control mixtures.