The effects of various aging techniques on asphalt low-temperature properties were investigated in three phases. In Phase I, it was shown that 38 days' aging of a 1-mm-thick asphalt film at 60 deg C and 1 atmosphere of air is approximately equivalent to 20 h in the pressure-aging vessel (PAV) of a 3.2-mm-thick film at 100 deg C after both have been rolling thin-film oven test aged. Low-temperature properties of the samples were found not to vary significantly between the PAV and environmental room-aged material. In Phase II of this work, a correlation was developed from the high-temperature parameter G*/sin(delta) at 58 deg C and 10 radians/s to correct the low-temperature performance grade when it is desirable to skip the long-term aging procedure. In Phase III of this study, it was shown that as asphalts are aged for extended periods, their relative ranks with respect to Strategic Highway Research Program low-temperature specifications may change. Furthermore, as asphalts are aged for extended periods, the low-temperature grades move from being limited by stiffness at short aging times to being limited by m-value (creep rate) at longer aging times.
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