Effect of Binder Performance Grade on the Dynamic Modulus Mastercurves of SP Ⅲ Superpave Mixes in New Mexico

摘要

This study evaluates the effects of asphalt binder's Performance Grade (PG) on the dynamic modulus (|E~*|) mastercurves of Superpave (SP) mixes typically found in the state of New Mexico. A total of three Hot-Mix Asphalt (HMA) mixes were collected. They were produced from three different binder grades and one with aggregate gradation containing 35% of Reclaimed Asphalt Pavement (RAP). Field collected HMA mixes were compacted and cored to cylindrical specimens. The specimens were then tested for dynamic modulus at five different temperatures and six different frequencies of loading. Mastercurves for all the HMA mixes are then developed and compared. A noticeable amount of divergence was found while comparing these mastercurves among each other. It is observed that stiffer binder produces HMA concrete with high dynamic modulus value. However, this trend is not always true. In case of HMA mixes with RAP, the dynamic modulus of the HMA increases considerably, though the mix has a softer binder. The dynamic modulus of these RAP-included HMA materials could be as high as twice the dynamic modulus of HMA without RAP.