Abstract
The main goal of this study is to develop a mathematical model to calculate an asphalt mix stability parameter referred to as gyratory stability (GS) from the compaction curve data specific to the Pine Superpave gyratory compactor. The GS is the summation of shear energy increments exerted on the sample during compaction. The researchers prepared and tested laboratory-mixed laboratory-compacted (LMLC) and plant-mixed laboratory-compacted (PMLC) samples to examine the sensitivity of the GS to the change in mix composition. A GS mathematical model was derived through conventional static equilibrium analysis of forces applied to the test samples during laboratory compaction. The results demonstrated that the GS was sensitive to the binder content and decreased with the increase in binder content for all mixes (with and without RAP) for different binder grades. Higher GS values indicate higher resistance to the shear forces. The results also demonstrated that there was a significant change in GS for some projects during production which indicates variations in mix composition or segregation during field production. The GS offers a convenient tool for quality control during the production of asphalt mixtures by examining the laboratory compaction data.