Impact of Gradation Relative to Superpave Restricted Zone on Hot-Mix Asphalt Performance

摘要: Significant controversy has revolved around the Superpave gradation specifications, in particular restricted zone, since completion of Strategic Highway Research Program (SHRP). Historically, dense-graded mixtures that encroach on zone had provided good performance prior to SHRP. However, current guidelines recommend gradations passing through not be used. A synopsis recent research related specifically impact hot-mix asphalt (HMA) is provided. The evolution and purpose are presented, along with findings both recently completed ongoing research. Studies involving laboratory full-scale accelerated tests plotting above (ARZ), (TRZ), below were considered. reviewed clearly suggests can achieved fine-graded (ARZ TRZ) no relationship exists between HMA rutting or fatigue performance. It suggested basis this recommendation eliminated from volumetric mixture design specifications.