Quantitative evaluation of rejuvenators to restore embrittlement temperatures in oxidized asphalt mixtures using acoustic emission source location techniques

Asphalt concrete;Embrittlement temperatures;Acoustic emission;Asphalt binder;Rejuvenator

Sun, Zhe ; Reis ; Henrique

关键词: Asphalt concrete;    Embrittlement temperatures;    Acoustic emission;    Asphalt binder;    Rejuvenator;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/90637/SUN-THESIS-2016.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Asphalt rejuvenator was designed to be an asphalt additive to revitalize, provide sealing and restore the properties of aged asphalt concrete. Its penetration depth into asphalt concrete, and its ability of restoring asphalt's embrittlement temperature was quantitatively investigated in this study using acoustic emission analysis and source location techniques. Four asphalt specimens, which have been oven-aged for 36 hours, were tested using the same acoustic emission approach after two, four, six, and eight weeks dwell time after being rejuvenated. Iterative and non-iterative acoustic emission source location approaches were used to determine the location of cracks inside the specimens in a low temperature environment. It was observed that the rejuvenator penetrated half of the height of the asphalt specimen at the end of the fourth week while the top half portion of the rejuvenated asphalt specimen has a lower embrittlement temperature than the bottom half portion. After four weeks of dwell time, the rejuvenator-treated samples had recuperated the embrittlement temperatures to the virgin condition. The rejuvenator kept acting upon the binder after four weeks of dwell time. At the end of the sixth week, the embrittlement temperature was observed to be homogeneous across the height of the specimen, and after eight weeks the specimen had an embrittlement temperature about 7 degrees lower than the embrittlement temperature of the virgin specimen. Furthermore, the concepts developed here were shown to be applicable to acoustic emission analysis on real pavements by installing the sensors only at the top surface of pavements.