Evaluation of AASHTO Rut Test Procedure Using the Asphalt Pavement Analyzer

This paper will discuss how high truck traffic, heavy axle loads, and high tire pressures have contributed to the demand for rut-resistant hot mix asphalt (HMA) on major highways. Therefore, there is a need for a test that can show the rutting resistance of mixes and that can be conducted in a timely manner during mix design processes or for quality assurance purposes. For these reasons, the Asphalt Pavement Analyzer (APA) has been widely adopted for checking the rutting resistance of HMA during the mix design process in many states. State procedures for APA testing are based on American Association of State Highway and Transportation Officials (AASHTO) TP 63. This AASHTO procedure was updated in 2007. However, questions remain related to the sample preparation, testing parameters, and rut depth measurement methods in the AASHTO procedure, as well as the suitability of the APA for screening mix designs and quality assurance purposes. A study was conducted at the National Center for Asphalt Technology (NCAT) to address some of these questions. The objectives of this study were to (1) determine the differences in APA rut depth measurements for two combinations of hose pressure and wheel load; (2) investigate the possibility of using automated rut depth measurements interchangeably with manual rut depths measured according to the revised AASHTO T 63 procedure; (3) evaluate the correlation between lab and field rutting performance; and (4) determine the APA rutting criteria for screening mix designs and quality assurance purposes. This study used field cores and laboratory specimens compacted to Ndes and the target air voids of 7 percent using HMA mixtures sampled during the construction of 12 test sections at the NCAT Pavement Test Track in 2006. The APA tests were conducted at two combinations of hose pressure and wheel load. The laboratory measured rut depths were then analyzed and compared with performance data collected at the NCAT Pavement Test Track. This study found that it was difficult to achieve 7 ± 0.5 percent air voids for APA specimens prepared in the field without prior experience with the mix. The manual and automated rut depths measured according to the revised AASHTO TP 63 procedure was statistically different in this study. For both combinations of wheel load and hose pressure, the APA rut depths for specimens compacted to the target air voids of 7 percent had better correlations with the field rutting performance. The revised AASHTO TP 63 procedure and the APA rutting criteria determined in this study can be used for screening mix designs and quality assurance purposes.

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  • English

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  • Accession Number: 01158633
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Apr 30 2010 1:17PM