Aggregate Gradation and Binder PropertiesThe aggregate gradation is critical to differentiate SMA and HMAbecause typical HMA is densely graded whereas typical SMA isgap-graded. The determination of the gradation of the extractedaggregate in this study was in accordance with AASHTO T30(AASHTO 2014a). The asphalt binder content was determinedfollowing AASHTO T164 (AASHTO 2014c) by extracting theasphalt binder from the field cores using 85% Toluene and 15%Ethanol by volume, and then the asphalt binders were recoveredusing the Abson method in accordance with AASHTO T170(AASHTO 2000).The performance grading tests were conducted in accordancewith AASHTO R29 (AASHTO 2014d). The MSCR tests were conductedin accordance with AASHTO T350 (AASHTO 2014b) toevaluate the rutting resistance of the recovered binder (D’Angelo2009). The MSCR test temperature was 58°C, which was the pavementhigh temperature in this project according to LTPPBind software.Nonrecoverable creep compliance is the residual strain afterthe creep and recovery cycle divided by the applied stress, whichhas been proven to be an indicator for rutting resistance (D’Angelo2009). The percentage of recovery (% recovery) is used to characterizethe relative difference of the strain values at the end of thecreep and the strain at the end of the recovery. Monotonic tests wereconducted at 20°C with a shear rate of 0.3 s−1 to determine thefracture energy and at 5°C with a shear rate of 0.075 s−1 to determinethe shear failure strain. The fracture energy and shear failurestrain are illustrated in Fig. 3. The fracture energy measured at 20°Cwas found to correlate with the field pavement’s bottom-up fatigue