A Wheel Tester. Quick. Simple.
Looking for a quick and simple test to evaluate the quality of an asphalt mixture? No special specimen fabrication. No specimen cutting. No gluing of instrumentation to specimens. Wait no longer! The Pine AFW1A Rotary Wheel Tester (RWT) fits the bill!
The City of Los Angeles acquired an early RWT, liked what it provided them, and used it to develop The Los Angeles Accelerated Rutting Test Method for permanent deformation and moisture susceptibility. The City of Los Angeles spent a decade refining the test and recently wrote it into their specifications.
The Los Angeles Accelerated Performance Test uses a standard Superpave gyratory specimen. After a specimen is compacted, it is cooled for at least 12 hours to ambient temperature. Then, it is wrapped in polyethylene stretch wrap. Next, the specimen is pre-conditioned for 2 hours in water at 60°C. Finally, the machine runs the test.
The results of a test are rut depth and number of cycles. The City of Los Angeles developed a table indicating the acceptable rut depth/cycle count combinations for various traffic loading situations. The City uses the test results to evaluate the quality of a mixed placed based on the traffic loading where the material was placed.
An ASTM standard test procedure is currently in process as part of Work Item WK64299.