Influence of Reduced Production Temperatures on the Adhesive Properties of Aggregates and Laboratory Performance of Fine Aggregate-Asphalt Mixtures

ABSTRACT Several new technologies have made production of hot mix asphalt (HMA) possible at lower temperatures by reducing binder viscosity and increasing mixture workability. The asphalt mixture produced using this technology is referred to as warm mix asphalt (WMA). In this study, three aggregates and two asphalt binders were used with a synthetic zeolite to produce six different types of Fine Aggregate Matrix (FAM), that were prepared at three different mixing and compaction temperatures. The first objective of this study was to evaluate the impact of reducing mixing and compaction temperatures on the mechanical behavior of these mixtures using the Dynamic Mechanical Analyzer (DMA). Secondly, the micro calorimeter was used to measure the total energy of adhesion (TEA) between the asphalt binder and aggregates treated at different temperatures. Results from the DMA indicate that shear modulus and fatigue cracking resistance of the FAM typically decreased when the mixing and compaction temperatures were reduced. TEA results indicate that residual moisture on aggregate surfaces at reduced mixing temperatures does not contribute significantly to the observed reduction in the mechanical results at lower mixing temperatures.