Comparison of mechanistic-empirical thickness design methods and predicted critical fatigue locations

With the use of mechanistic-empirical rigid pavement design methods becoming more widespread, it is important to note the differences of these methods in terms of their sensitivity to input parameters, conservativeness of the design thicknesses, and failure modes predicted. This study further demonstrated the sensitivity of input parameters such as joint spacing, shoulder type, traffic level, climatic location, and built-in curl level on the fatigue failure mechanisms predicted by several design methods. The use of widen lanes was also found to predict different fatigue failure mechanisms between design methodologies due to the assumptions of each method. An investigation into the sensitivity of the level of built-in curling showed that the thinnest design thickness does not necessarily occur with the absence of this parameter, but is minimized at a built-in curling level of approximately -6°C.