Fatigue strength of asphalt concrete pavement on orthotropic steel deck considering temperature factor

Abstract

Fatigue of any material is a process when micro-damage accumulates because of multiple load applications. The result is the appearance of defects after a while. Asphalt concrete pavement on orthotropic steel deck (OSD) of roadway bridges is prone to fatigue failure. There are several reasons for this. Firstly, there is a large number of vehicle impacts for pavement service life. Secondly, the pavement lies on the flexible load-bearing elements of the roadway deck. This leads to high stresses in the asphalt concrete. In general, stress limitation prevents fatigue defects. The value of this limit is set according to the results of fatigue calculation. This calculation is performed for main load-bearing elements but not for the pavement on the roadway. In this article the necessary of fatigue strength calculation of pavement on orthotropic steel deck is justified. Also, disadvantages of the existing fatigue calculation method of pavement on the ground are noted. This design method is not applied for fatigue strength calculation for OSD pavement because of these disadvantages. Available experimental results of fatigue strength of asphalt concrete are analyzed. As a result, the need to take into account the temperature factor is established. The hypothesis of linear summation of damages allows to take into account the change of fatigue strength of asphalt concrete at different temperatures. In the article the endurance of asphalt concrete as part of the typical pavement system on OSD is evaluated in accordance with the described approach. In addition, the tasks for the future are set. Solution of these tasks will allow to developing the method of pavement calculation on different bridges.