Effects of the asphalt penetration grade and the mineralogical composition on the asphalt-aggregate bond

Abstract

[Abstract:] This investigation analyzes the loss of bonding between the asphalt binder and the aggregate particles produced by water in hot-mix asphalt pavements. Three asphalt penetration grades were used: B35/50, B50/70, and B160/220. Four different types of aggregates were chosen due to their different expected stripping performances: hornfels, feldspathic schist, gabbro, and dolomitic calcite. To research the loss of adhesion, two laboratory test methods were compared: the rolling bottle method and the boiling water test. The results indicate that a higher asphalt-aggregate bond correlates to a lower asphalt penetration grade. To achieve significant asphalt-aggregate bond improvement, the difference between asphalt penetration grades must be noticeable.