Influence of Binary Blended Fillers on Long-Term Aging Effect and Rutting Performance of Warm-Mix Asphalt

Abstract

Warm-mix asphalt (WMA) is produced at lower temperatures—about 30°C–40°C lower—than hot-mix asphalt (HMA). Huge amounts of brick dust (BD) and fly ash (FA) are generated every year throughout the world, causing an environmental hazard, and their disposal is a serious problem. In addition, the high mixing temperature of HMA production increases environmental load. This study evaluated warm mixes made using organic wax and chemical-based technologies. Two types of filler material, i.e., FA and BD, were used as binary blended fillers (BBF). Cylindrical Marshall specimens were prepared and subjected to moisture susceptibility tests for both aged and unaged conditions. The durability of these samples was tested by evaluating the tensile strength ratio using the modified Lottman test method. The cohesion resistance of the mixtures was evaluated by Cantabro loss. Furthermore, a wheel tracker test (WTT) setup was used for rutting evaluation. Results revealed that the use of BBF in mixes led to a marked increase in mechanical properties. Microstructural behavior was studied using scanning electron microscopy (SEM) images for particle-size distribution. The statistical test indicated a significant difference in stability values and rut depths.