Flexible pavement drainage system effectiveness

摘要

Moisture can significantly affect flexible (asphalt) pavement performance. As such, it is important to remove moisture as quickly as possible from such pavements, especially to avoid allowing moisture into the pavement subgrade. Using an appropriate drainage system is one method to remove moisture from pavement structures. The objective of this research is to evaluate the effectiveness of flexible pavement drainage systems using currently specified materials to determine if, and when, the drainage system can be safely excluded from the pavements. Moreover, the effects of filter layer and edge drains are also examined.Laboratory experiments were performed to obtain the hydraulic properties of asphalt materials and used in the numerical modeling of pavement sections. The results indicate that drainage layers do effectively lower the subgrade moisture content. Also, while the results show that either a dense-graded aggregate or a dense-graded asphalt mixture can be used as a filter layer between the subgrade and the open-graded drainage layer, the subgrade tends to have lower moisture when a granular filter layer is used. Finally, the results indicate edge drains have a positive effect on flexible pavements, especially on pavements that do not contain a drainage layer. (C) 2019 Elsevier Ltd. All rights reserved.