Regional Calibration of Asphalt Concrete Layers Permanent Deformation Model for Mechanistic-Empirical Pavement Design Guide

It is important to calibrate a permanent deformation model in the Mechanistic-Empirical Pavement Design Guide (MEPDG) based on local materials, traffic information, and environmental conditions. The objective of this paper is to calibrate a prediction model using measured rutting data collected from flexible pavements located in Jiangsu Province. The number of equivalent standard axle load repetitions, effective mean annual air temperature, and a saturated traffic computation method were introduced to simplify the calculation for an elastic multilayer system. The material properties for each asphalt concrete sublayer were chosen depending on the pavement temperature field prediction. To account for the different mechanistic responses in asphalt concrete layers on a semi-rigid base, the correction factor k₁, considering the effects of total asphalt concrete layer thickness and depth to computational points, was revised based on field rutting measurements at various asphalt concrete layer depths in thin and thick pavements, respectively. By comparing the measured rut depths to predicted values from the MEPDG model, the optimum combination of field calibration factors β₂ and β₃ was determined so that the coefficient of variation was minimal, while optimized β₁ was found simultaneously by the least square method.