The pavement mechanistic-empirical design (PMED) is a modern approach to designing new and rehabilitated pavements. MDOT uses the American Association of Highway and Transportation Officials (AASHTO) 1993 design methodology for rehabilitation pavement designs. MDOT designs hot mix asphalt (HMA) overlay over rubblized plain cement concrete (PCC) pavements as new flexible pavement, modeling rubblized PCC layer as an unbound aggregate base with a modulus of 70,000 psi. The PMED offers an alternative design option [HMA overlay over fractured jointed plain cement concrete (JPCP)] for rubblized pavement. This study analyzes the most optimum design approach and HMA input level for rubblized pavements in Michigan. The study compared the predicted performance using global and locally calibrated models for new and overlay designs for rubblized pavements at all three hierarchical input levels. The global performance predictions at input Levels 1 and 3 showed negligible differences in new and overlay design options. Local calibration of new and overlay design at input Level 1 produced better results with minimum standard error of estimate (SEE) and bias. However, local calibration results at input Level 3, where Level 1 data is unavailable, are also acceptable. The study evaluated the impact of local calibration on the new and overlay design by designing 11 pavement sections with variable traffic data. An overlay design resulted in 1.5-inch thinner pavements than AASHTO93 and 0.4-inch thinner than the new design using PMED. The difference between new and overlay designs is not significant based on available data. Therefore, a new design (MDOT’s existing practice) using input Level 1 (if data are available) is recommended for rubblized pavement in Michigan. Finally, the study documented the sensitivity of the calibration coefficients using scaled sensitivity coefficient analysis and compared SSCs-based ranking with normalized sensitivity index (NSI) ranking.
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