Mechanistic-Empirical Design for Rubblized Pavements in Michigan

Abstract

Pavement mechanistic-empirical design (PMED) is a modern approach to designing new and rehabilitated pavements. The Michigan Department of Transportation (MDOT) follows the current guideline methodology for rehabilitation designs, utilizing hot-mix asphalt (HMA) overlays on rubblized plain cement concrete (PCC) pavements as new flexible pavement. PMED offers an alternative of HMA overlay on fractured jointed plain cement concrete (JPCP) for rubblized pavements. This paper investigates the optimal design approach and HMA input level for rubblized pavements in Michigan, comparing performance predictions using global and locally calibrated models across three input levels. Results indicated negligible differences between new and overlay designs at global performance predictions for input Levels 1 and 3. Local calibration at Level 1 produced better outcomes, but Level 3 results were also acceptable, barring the thermal cracking model. The study analyzed 11 pavement sections, revealing that HMA thicknesses were, on average, 1.02 cm thinner than current guideline designs. A new flexible pavement design with Level 1 data input is recommended for rubblized pavements in Michigan. This study aims to improve HMA overlay design on rubblized pavements, promoting efficient, cost-effective pavement rehabilitation. Although several studies are available on implementing the PMED for new pavements, research on rehabilitated pavements is limited. Moreover, different design options and input levels in the PMED and data unavailability make the design of rehabilitated pavements more challenging. By comparing PMED design options (overlay and new), calibration methods, and input levels (Levels 1, 2, and 3), the study seeks to enhance prediction accuracy for key pavement distresses. These findings will aid practitioners in selecting the optimal design and input level for effective rehabilitation, especially when data availability is challenging. The study’s findings validate the MDOT current practice of treating HMA overlays over rubblized concrete as new flexible pavements.