Volume 27, Issue 1 (January 1999)
Effect of Asphalt Mix Design Method on Binder and Gradation Selection
To investigate the hypothesis that Superpave Volumetric mix design yields superior performing mixes overall, the Portuguese Road Directorate (JAE) compared the performance of Superpave mixes with the performance of other mixes. The comparisons were made with gradations that pass through, above, and below the restricted zone. Performance was evaluated using the Marshall test, the Hveem test, the Repetitive Simple Shear Test at Constant Height, the Four Point Bending Fatigue Test, and the French Wheel Tracking Device. These research efforts led to consideration as to what extent the binder and gradation selections are dependent on the mix design tool. The results indicate that some Superpave mixes yield the lowest laboratory performance in some of the tests.