Local Calibration and Implementation of the Mechanistic-Empirical Pavement Design Guide for Flexible Pavement Design

Abstract

This paper presents the results of the calibration and implementation of the Mechanistic-Empirical Pavement Design Guide (MEPDG) for the design of flexible pavements in Italy. Local input data for traffic, climate, materials, and subgrade (foundation soil) are evaluated and subsequently arranged, as required by the MEPDG to be used in the associated software. The coefficients of the distress models are derived by means of a comparison between the performances predicted by the MEDPG and those predicted by theoretical equations, which are believed to represent the local distress process of a pavement and/or assumptions prevalently made in Italy. A wide parametric analysis is performed so that the influence in design process attributed to load spectra, temperature, dynamic modulus of asphalt concrete, and resilient modulus of subgrade is shown. The results obtained from MEPDG are compared, according to the hypothesis of zero-maintenance during the service life of a pavement, to those derived from using a local mechanistic-empirical method. As a consequence, the difference between these two design methods is quantified. For a verification of the results obtained from the MEPDG, the 1993 AASHTO guide is used. Subsequently, by using the MEPDG for rehabilitation, a maintenance strategy based on two resurfacings of wearing course of pavement is also investigated, and its effect on the extension of service life of a pavement in contrast with zero-maintenance is shown. Therefore, this work provides the knowledge for locally implementing the MEPDG with significant success both for the assumption of zero-maintenance and resurfacing treatments during the service life of a pavement.