| Since the completion of the Strategic Highway Research Program (SHRP), the Nevada Department of Transportation (NDOT) has conducted several research efforts on the Superpave mix design method. Previous research with the recommended Superpave gradation has produced hot mixed asphalt (HMA) inferior to NDOT's Hveem mix design. NDOT is now conducting research with a new Superpave gradation which passes through the restricted zone.; Laboratory testing was used to determine the rut resistance, moisture sensitivity, and overall strength of each mixture. Rut resistance was assessed using the Asphalt Pavement Analyzer (APA), Superpave Shear Tester, (SST), and the Repeated Load Triaxial Test (RLT). Moisture sensitivity was assessed using AASHTO T-283 based on the Resilient Modulus (Mr) and the Indirect Tensile Strength (TS). Long-term moisture sensitivity was also assessed using eighteen cycles of AASHTO T-283 based on the Mr. The strength of each mix was assessed by developing the dynamic modulus master curve. |
