Low-temperature and aging characteristics of Nevada's asphalt binders and mixtures

The deterioration of flexible pavements due to low temperature cracking is a significant and costly problem in the State of Nevada. In 1993, the Nevada Department of Transportation initiated several research efforts aimed at exploring Nevada's problem with this distress. Through two related projects, the University of Nevada was contracted to evaluate several newly developed low temperature performance tests under Nevada's conditions. The focus of the investigation was to determine the applicability of the tests for characterizing the low temperature response of Nevada's asphalt binders and HMA mixtures. This thesis summarizes Nevada's experience with the SHRP low temperature tests and specifications highlighting the effectiveness of the Superpave PG binder grading system and Thermal Stress Restrained Specimen Test. The contribution of asphalt aging to Nevada's cracking problem is also included in the paper following efforts to validate the Superpave short and long term aging protocol for use in Nevada.