Prediction of Field Performance of Asphalt Concrete Overlays in Louisiana Using a Tree-Based Algorithm: Fid-Bau Portal

Prediction of Field Performance of Asphalt Concrete Overlays in Louisiana Using a Tree-Based Algorithm

Mousa, Momen R. / Elseifi, Mostafa A.

In Louisiana and many other states, the design pavement service life (PSL) for structural asphalt concrete (AC) overlays is typically assumed 20 years. However, research studies showed that the actual pavement service life is rarely monitored. The objective of this study was to assess the field performance of structural overlays in Louisiana and to estimate PSL under field conditions. Considering all the distresses, about 75% of the projects had a pavement service life less than 20 year and the mean PSL for all the projects was 17±6 years. This suggests that the overlay thickness designed with the 1993 ASSHTO procedure using a pavement service life (PSL) of 20 years may not last the entire design period without additional maintenance activities. Results also showed that random cracking, followed by rutting, were the primary causes of long-term failure in the evaluated projects. A methodology was developed to adjust the designed overlay thickness by the AASHTO 1993 design procedure such that the actual PSL matches the design PSL. This methodology included the development of an extreme gradient boosting (XGB) classification model to predict PSL with an acceptable level of accuracy based on sensitivity, accuracy, and specificity. This approach may be used by transportation agencies in the planning phase of future maintenance and rehabilitation activities and in the design phase of AC overlays. This would also ensure adequate allocation of maintenance and rehabilitation funds by a state agency.