Ranking of the Commonly Used Aggregate and Asphalt Binder Systems in Arkansas

The Arkansas Department of Transportation (ARDOT) Maintenance Division is concerned about the use of certain aggregates in asphalt mixture because of their durability and performance issues. Good performance of the pavements can be ensured by selecting good-quality aggregates along with asphalt binders that can produce compatible aggregate-binder systems. The primary goal of this research was to determine proper asphalt binders and aggregates for the construction of highways in Arkansas. Three performance grade (PG) asphalt binders, namely PG 64-22, PG 70-22, and PG 76-22, prepared from two different crude sources, were investigated. This study also included four types of ARDOT-commissioned aggregates, namely gravel, sandstone, limestone, and dolomite, from four quarries throughout Arkansas. Selected properties of asphalt binders and aggregates (e.g., physical, mechanical, and chemical) were evaluated by performing a series of routine laboratory tests. To evaluate the performance of the asphalt mixtures, work of cohesion, work of adhesion, and boiling resistance tests were conducted. These aggregates, binders, and aggregate-binder systems were ranked based on the properties obtained from laboratory tests. In general, any combination of dolomite or limestone with a stiffer binder such as PG 76-22 or PG 70-22 is expected to be superior to an asphalt mixture with either sandstone or gravel. The outcomes of this research will help highway agencies and pavement professionals in selecting suitable asphalt binders and aggregates for long-lasting pavement construction.