Mechanistic–empirical damage analysis and impacts of reduced tire pressure on thaw weakened flexible pavements using the AI and MEPDG models

Abstract

A damage analysis was conducted on a spring weight restricted flexible pavement to quantify the effects of reduced tire pressure on pavement life and to compare the damage predictions from the Asphalt Institute (AI) and the Mechanistic Empirical Pavement Design Guide (MEPDG) models. The models were used to predict the number of repetitions to fatigue and rutting failure at three maximum loads and at high and low tire pressures. Based on the results, the AI and MEPDG predictions were statistically different for both fatigue cracking and rutting damage, based on the t-test at 95% confidence limits. The AI model predicted 31% lower fatigue damage than the MEPDG, but 56% higher rutting damage. However, both models produced similar trends in predicting the relative effects of reduced tire pressure and load levels on pavement life. The methodology and results of the analysis are presented in this paper.