DEEP IN-SITU RECYCLING OF ASPHALT CONCRETE PAVEMENTS AS GRANULAR BASE: DESIGN, CONSTRUCTION AND PERFORMANCE

The California Department of Transportation conducted a pilot project for evaluating a pulverization process for asphalt concrete to use it as a base material. The technique is relatively new to California and in concept, presents several advantages over the conventional overlay strategy. The process was evaluated in terms of constructability and pavement performance. The process provided Caltrans engineers with lower initial costs than overlay with digouts in the wheelpath. Field and laboratory testing was conducted at the University of California Pavement Research Center to evaluate the new materials using falling weight deflectometer deflections, dynamic cone penetrometer, and triaxial testing. The results of the investigation indicate that the pulverized base material is expected to perform better than the conventional base materials used in the study. The results also show greatly improved properties of granular base materials, including this recycled material when the relative density is increased from 95 to 100 percent using Caltrans standard compaction