Evaluation of the MEPDG Using Asphalt Material Inputs Obtained From Plant Mix

• Autores: STACEY D. DIEFENDERFER
• Localización: Asphalt paving technology, ISSN 0270-2932, Vol. 80, 2011, págs. 101-134
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • The Virginia Department of Transportation (VDOT) is expecting to transition to using the methodology described in the Guide for the MechanisticEmpirical Design of New & Rehabilitated Pavement Structures (MEPDG) in the near future, and decisions must be made regarding the hierarchical level of desired asphalt material inputs and the extent to which asphalt mixture characterization must be performed. Thus a study was undertaken to investigate the effects of these variables using input values measured from 11 typical plant mixtures (i.e., three surface, four intermediate, and four base mixtures). The predicted fatigue and rutting distresses were used to evaluate the response of the MEPDG to differences in the mixture properties and to assess the future needs for implementation. Two example pavement sections were modeled: a primary and an interstate roadway section. Pavement distress data were compiled for an interstate and primary route corresponding to the modeled sections and were compared to the MEPDG-predicted distresses.

    Predicted distress quantities for fatigue cracking and rutting were compared to the calculated distress model predictive errors to determine if the material property input levels were statistically different. There were differences between all rutting and fatigue predictions using level 1, 2, and 3 asphalt material inputs, but they were not statistically significant. Various combinations of level 3 inputs showed expected trends in rutting predictions when increased binder grades were used, but the differences were not statistically significant when the calibration model error was considered. Fatigue distress predictions were approximately comparable to the pavement distress data, but the model predictive errors were greater than the distress predictions.

    Although this study was limited, it indicated several steps VDOT should take prior to implementing the MEPDG. Additional work to identify the source of predictive insensitivity to changes in both asphalt mixture properties and the level of input values is necessary. The comparisons of predicted fatigue and rutting distresses to pavement distress data for the primary and interstate pavement indicate the need to consider local calibration and verification of the predictive models.

    Key words: mechanistic-empirical pavement design guide, implementation, mixture characterization _____________________________________________________ 1Research Scientist, Virginia Transportation Research Council The oral presentation was made by Dr. Diefenderfer.