Preferred Aggregate Base Courses for Low-Volume Roads

The Local Road Research Board and the MnDOT Office of Materials and Road Research are interested in learning about the preferred aggregate base courses used for low-volume asphalt and concrete pavements in states with climates that are similar to Minnesota's, particularly in how other state transportation agencies' preferred aggregate bases compare to MnDOT's Class 5 virgin aggregate. To inform an analysis of other aggregate base courses, researchers surveyed selected state transportation agencies about their preferred aggregate for low-volume asphalt and concrete pavements and a secondary aggregate that is used nearly as frequently as the preferred aggregate. This Transportation Research Synthesis presents the findings from the survey and compares the characteristics, specifications and performance of the materials.