For pavement rehabilitation design, the current mechanistic–empirical (ME) pavement design guide provides three levels of analysis methodology to determine dynamic modulus master curves for existing asphalt pavements. First, the ME pavement design guide recommends that Witczak’s predictive equation is employed to obtain the “undamaged” modulus master curve. Depending on the chosen level of analysis, either a falling weight deflectometer test (Level 1) or a condition survey (Levels 2 and 3) is conducted to determine the damage factor(s). The damage factor is used to shift the undamaged master curve downward to match the field conditions and obtain the “damaged” master curve. In this study, two pavement structures in North Carolina Highway 96 were selected to evaluate the accuracy of the ME pavement design guide using its three levels of analysis. Because this roadway is a multilayer full-depth pavement, the extracted field cores were divided into a top layer, bottom layer, and total core for investigative and comparative purposes. Accordingly, both laboratory measurements and pavement ME predictions of the dynamic modulus values were conducted separately. Results show that the predicted undamaged master curves are always higher than the measured master curves and Levels 1, 2, and 3 can each lead to significantly different damaged master curves. Considering both efficiency and accuracy for transportation agency practice, the Level 1 method is recommended, and if the existing pavement is a multilayered asphalt pavement, a total core extracted from all the layers is recommended to generate the input properties for Witczak’s predictive equation.

对于路面修复设计，当前的机械-经验（ME）路面设计指南提供了三个层次的分析方法，可以确定现有沥青路面的动态模量主曲线。首先，ME路面设计指南建议采用Witczak的预测方程式来获得“未损坏”的模量主曲线。根据所选择的分析级别，进行跌落偏折仪测试（级别1）或状况调查（级别2和3）以确定损坏因素。损坏因子用于使未损坏的主曲线向下移动以匹配现场条件，并获得“已损坏”的主曲线。在这项研究中，选择了北卡罗来纳州高速公路96的两个路面结构，以使用其三个层次的分析来评估ME路面设计指南的准确性。由于该巷道是多层的全深度铺装路面，因此为研究和比较目的，将提取的田间岩心分为顶层，底层和总岩心。因此，分别进行了实验室测量和动态模量值的路面ME预测。结果表明，预测的未损坏的主曲线始终高于测量的主曲线，并且级别1、2和3各自可以导致明显不同的损坏的主曲线。考虑到运输代理实践的效率和准确性，建议采用1级方法，如果现有路面为多层沥青路面，则建议从所有层中提取总芯，以生成Witczak预测方程式的输入属性。