Evaluating and Predicting Flexible Pavement Performance

Abstract

The Ethiopia Road Authority (ERA) pavement design guide uses empirical models which were adopted and modified from AASTHO design guides. As with any empirical model, the prediction capabilities are limited to the conditions for which it was developed. Mechanistic Empirical Pavement Design Guide (MEPDG) has been recently developed to account for increase in truck traffic and minimize premature failure of pavements. Since the new design uses mechanistic approach, it is expected that the design guide can better predict performance of pavements. In addition, mechanistic approach allows use of design guide for different pavement and environmental conditions by calibrating model parameters for different conditions. Thus, the design guide can be used for Ethiopia roads and was focus of this study.The mechanistic empirical design requires parameter inputs in four different modules: Traffic, materials, environment & pavement structure. These parameters may or may not be available for Ethiopia conditions. To identify parameters that influence performance prediction significantly, the design guide was evaluated for Humbo to Arba Minch road pavement and environmental conditions. After successful identification of parameters, the MEPDG analysis was performed and compared with the ERA design guide.The results of the analyses indicated that the expected performance can be achieved at lower Equivalent Single Axle Loads (ESALs) but not at higher ESALs.