Using Gyratory Compaction to Investigate Density and Mechanical Properties of Roller-Compacted Concrete

Roller-compacted concrete (RCC) is a durable, economical, low-maintenance material for low-speed, heavy-duty paving applications, including industrial and multimodal pavements. However, it is difficult to prepare laboratory specimens to represent field performance, because RCC is very dry and requires considerable compactive effort to achieve field densities. The gyratory compactor, commonly used to prepare hot-mix asphalt specimens, may be used in preparing specimens for laboratory testing. Materials and mix designs from two industrial paving projects were used to prepare specimens for comparison. Field results indicated that the gyratory compactor produced specimens with mechanical properties consistent with those achieved in the field. Specimens had high strength and consistent density, with low variability. The gyratory compactor may be used to replace other methods presently used for preparing RCC specimens such as the modified Vebe apparatus, the vibrating table, and the vibrating hammer. These methods have limitations that may be overcome with the gyratory compactor because of its consistency and its compatibility with field results. The effects of density and specimen aspect ratio on compressive and splitting tensile strength were investigated. The number of gyrations applied to the specimen may be used to duplicate the desired field density. For the industrial pavements investigated, approximately 60 gyrations accurately replicated field conditions.