Evaluation of structural performance of thinasphalt pavement reinforced with wicking geotextiles over expansive soils

This research provides a comprehensive evaluation of the effects of a wicking geotextile capable of multiple functions, including separation and reinforcement and gravity and capillary suction-induced drainage for subsurface layers in flexible pavements built over expansive soils. Two test sections were designed and constructed near central Texas, which were prone to distress from cyclic moisture-induced strains related to expansive soils, during the Fall of 2018. The base layers in the first and second sections were constructed with reclaimed asphalt pavement and crushed stone aggregate, respectively, and wicking geotextiles were installed between the base and subgrade layers. The adjacent lane to the test sections was selected as the control section. Falling weight deflectometer (FWD) testing was conducted to evaluate the in-situ moduli of the pavement layers. Multiple performance indicators were selected to compare the performance of reinforced and control sections. A performance prediction software program was used to investigate the performance of the sections according to the mechanistic-empirical design and analysis approach. The results showed the rapid removal of moisture has a significant impact on controlling the permanent deformation of the pavement layer. FWD results revealed that the reinforced layer helped to improve the base and subgrade moduli values. The performance prediction results showed the wicking geotextile has the potential to be used for reinforcing the pavements constructed over expansive soil