Evaluation of the asphalt pavement analyzer for accelerated testing of the relative rutting susceptibility of hot mix asphalt

In the early 1990's, $50 million of asphalt related research was conducted as part of the Strategic Highway Research Program (SHRP). The SHRP researchers identified rutting as a major cause of distress in Hot Mix Asphalt (HMA)They developed the Superpave mixture design and analysis system in part to help reduce this mode of distress.

The Superpave procedure does not currently include a proof-test to assess the relative rutting susceptibility of HMA. Such a test would be very useful in the design and evaluation of HMA (Petros, 1999). The objective of this study was to evaluate the merits of the Pavement Technology, Inc. (PTI) Asphalt Pavement Analyzer (APA) as a proof-test to predict the relative rutting susceptibility of HMA in Tennessee.

Thirty-four mixes from various locations across the state of Tennessee were compacted into test specimens and tested in the APA. The Superpave Gyratory Compactor (SGC) was used to produce pill specimens and the PTI Asphalt Vibratory Compactor (AVC) was used to make beam specimens.

Based on the test results contained herein, the APA appears to be well suited for accelerated proof testing of HMA in the laboratory. The data also indicated that the APA is sensitive to several of the primary factors known to cause rutting of HMA. Either SGC pill or AVC beam specimens can be used in the APA. However, the AVC beams exhibited a high variability between specimens, primarily due to inconsistent compaction.