Postmortem evaluation of accelerated rate of raveling of in-service asphalt pavements in arid climatic conditions-case of Kuwait

This research study aimed to assess the cause(s) of accelerated rate of raveling observed in the in-service asphalt pavements and its impact on the performance of these pavements under arid climatic conditions. This study is a step forward towards the overall effort to determine the best practice to deal with the premature raveling problem in the arid climatic conditions of Kuwait. Five raveled pavement sections were identified for this study. Pavement distress surveys were conducted to estimate the pavement condition indices of the selected pavement sections. Additionally, several cores were extracted from the pavement sections for postmortem investigation. The laboratory evaluation included resistance to moisture damage and rutting, extracted aggregate sieve analysis, and recovered asphalt binder penetration and performance grading (PG). The pavement distress survey results showed that all pavement sections were significantly deteriorated due to raveling, indicating significantly poor performances. Laboratory test results showed, that almost all sections exhibited significantly low resistance to moisture damage and permanent deformation, indicating a high susceptibility to raveling. Furthermore, the PG and penetration test results of the extracted asphalt binders showed that all sections exhibited significantly high levels of oxidative aging and deterioration rates for their respective in-service ages. By combining all test results, it can be concluded that the arid weather and heavy traffic conditions associated with the asphalt binder poor performance have significantly weakened the adhesion bond between the aggregate particles and the asphalt binder resulting in a major stripping and raveling problem in Kuwait.