Prediction of fatigue and rutting premature distress in viscoelastic flexible pavement layered for different loading condition using Mechanistic-Empirical Method

Abstract

The main two premature failures among all types of distresses are fatigue and rutting due to their main relation with performance pavement. These failures are caused by variations in heavy axle-loaded trucks, designing inappropriate mixture, and conventional design methodologies used in the pavement design industries. Premature distresses should be avoided for proper performance and serviceability. As a result, a Mechanistic-Empirical Method based design approach using computer programming, such as KENPAVE software, is required to avoid conventional design errors. The KENPAVE software tool is used to calculate accurate stresses and strains in the asphaltic pavement, which are then used to determine fatigue and rutting failures. HMA layers act under real field conditions as viscoelastic material, and their mechanical responses depend on temperature and loading. This research aimed to study the overloads on pavement and the changing temperatures throughout the year in Mosul city on the performance and design life of the pavement by using the Mechanistic-Empirical Method (M-E) to investigate the most influential properties under the temperature change to improve the design of the pavement structures. The results revealed the importance of the impact that climate change may have on the service life of the pavement, as the design life decreases with the increased loads applied on the pavement, where the design life decreases to 0.05 of its value when the loads are increased to twice the standard load. While the vertical stress and the damage ratio increase with the change of temperature and with the increase in the axle loads, it was found that the percentage of the damage ratio increases by 5.5 times when the axle loads are increased to 1.5 of the standard loads. These changes in the assessment of the pavement life cycle and thus their effect on future maintenance requirements must be verified.