Abstract
Towards developing a method capable to assess the efficiency of rejuvenators to restore embrittlement temperatures of
oxidized asphalt binders towards their original, i.e., unaged values, three gyratory compacted specimens were
manufactured with mixtures oven-aged for 36 hours at 135 °C. In addition, one gyratory compacted specimen
manufactured using a short-term oven-aged mixture for two hours at 155 °C was used for control to simulate aging during
plant production. Each of these four gyratory compacted specimens was then cut into two cylindrical specimen 5 cm thick
for a total of six 36-hour oven-aged specimens and two short term aging specimens. Two specimens aged for 36 hours
and the two short-term specimens were then tested using an acoustic emission approach to obtain base acoustic emission
response of short-term and severely-aged specimens. The remaining four specimens oven-aged for 36 hours were then
treated by spreading their top surface with rejuvenator in the amount of 10% of the binder by weight. These four specimens
were then tested using the same acoustic emission approach after two, four, six, and eight weeks of dwell time. It was
observed that the embrittlement temperatures of the short-term aged and severely oven-aged specimens were -25 °C and -
15 °C, respectively. It was also observed that after four weeks of dwell time, the rejuvenator-treated samples had
recuperated the original embrittlement temperatures. In addition, it was also observed that the rejuvenator kept acting
upon the binder after four weeks of dwell time; at eight weeks of dwell time, the specimens had an embrittlement
temperature about one grade cooler than the embrittlement temperature corresponding to the short-term aged specimen.
