Calibrating and Validating Overlay Tester-Based Fatigue Cracking Model with Data from National Center for Asphalt Technology

There is a national movement to develop mechanistic-empirical methods for the design of flexible pavements, for which fatigue cracking is a major distress mode. Fatigue cracking has been studied for several decades. Different types of fatigue cracking models have been proposed. After a review of existing fatigue cracking models in the literature, it was found that the overlay tester-based fatigue cracking model was a rational choice for predicting the development of fatigue cracking and for incorporation into the mechanistic-empirical design system. The main features of the overlay tester-based fatigue cracking model include incorporation of both crack initiation and crack propagation stages; involvement of fracture properties (i.e., A and n) of every asphalt layer, if the flexible pavement has multiple asphalt layers and each layer material is different; and use of the simple overlay tester for determining the fracture properties required for predicting both crack propagation and crack initiation. The pr...