Lifecycle Simulation for Unbonded Concrete Overlay Design

Abstract

An unbonded concrete overlay (UBCO) is an increasingly popular technique for pavement rehabilitation. Its current thickness design is based on empirical equations or highly simplified mechanistic models. This paper conducts a lifecycle simulation study for UBCO for the first time. Its sophisticated three-dimensional finite-element model is created and the fatigue reflection crack initiation and propagation under the cyclic traffic loading are simulated. The fatigue parameters are calibrated and corrected according to the size effect law. The simulation results reveal the three-dimensional cracking mechanism of the UBCO and show that increasing the overlay thickness is the most efficient way to improve the fatigue life. The present study offers a practical approach for evaluation of the UBCO’s fatigue life and thus sheds light on a next-generation fatigue life–based design procedure for the UBCO.