Enhancing Mechanistic–Empirical Pavement Design Guide Rutting-Performance Predictions with Hamburg Wheel-Tracking Results

To analyze the effects of mix production variability on pavement rutting, this paper compares predictions from the Mechanistic–Empirical Pavement Design Guide (MEPDG) with test results from the Hamburg wheel-tracking device (HWTD). An experiment was conducted during research to establish correlations effectively between the two methods. The experiment consisted of using volumetric data to model asphalt mixes and pavement structures in the MEPDG and to evaluate the sensitivity of these mixes in comparison to results obtained in the laboratory under the HWTD. The research study analyzed two limestone mixes: a coarse, dense-graded hot-mix asphalt (Type C) and a fine, dense-graded hot-mix asphalt (Type D), as defined in the 2004 Texas Department of Transportation Standard Specifications for Construction and Maintenance of Highways, Streets, and Bridges. The research found that the permanent deformation model embedded in the MEPDG supported the general performance trend observed in the laboratory under the HWTD. Both the MEPDG and the HWTD showed better performance for the Type C mix than for the Type D mix. However, the HWTD showed that small variations in mixture properties, such as mixture gradation within construction tolerance specifications and minor deviations from the optimum in binder content, had significant effects on pavement performance that were not captured by the MEPDG at a Level 2 mixture design. This finding suggests that laboratory results under the HWTD could be used to fine-tune the rutting performance models in the MEPDG until actual field performance data become available.