Volume 37, Issue 5 (September 2009)
Prediction of In-Service Fatigue Life of Flexible Pavements Based on Accelerated Pavement Testing
Full-scale accelerated pavement testing (APT) is a supplement to typical laboratory procedures. As such, it leads to significant advances in practice and economic savings for the evaluation of new pavement configurations, stress level related factors, new materials, and design improvements. This type of testing closely simulates field conditions; however, it does not capture actual pavement performance because of the limited ability to address long-term phenomena. Therefore, to fully utilize the benefits of APT, there is a need for a methodology to predict the long-term performance of in-service pavement structures based on the generated test results in order to account for such differences. The bias correction factor (BCF) or bias correction functions should account for the quantifiable differences between the fatigue life of the pavement site under APT and the in-service conditions. The BCF represents an improvement of the currently used “shift factors” since they are more general and are based on laboratory testing or computer simulations. By applying the proposed methodology, APT performance results from a structure similar to an in-service structure can be used to perform four-point bending beam tests and structural analysis to obtain an accurate estimate of the necessary BCF to estimate in-service performance.