ABSTRACT
The binder course plays a very important role in strengthening the interface between new and existing pavement layers, which is highly related to shear damage of the interlayer and many other kinds of defect. Due to the inappropriate design of the binder course, such defects caused by interlayer shear fracture frequently occurred in alpine regions such as in Qinghai province in China. Taking into account the binder course shear strength as the key evaluation parameter, the optimal aggregate covering ratio and asphalt content were determined by tests, which simulated the working state of the binder course using composite specimens shaped in the lab. Based on that, the influences of different aggregate size, lithology, pretreatment and asphalt binder type were further researched and analyzed. The results of this paper can be a supplement to the current design parameters for binder courses in the Chinese specifications, and also can provide references for other similar research.
