Using Reclaimed Asphalt Pavement in Backfilling Works Beneath the Structures

Reclaimed asphalt pavement (RAP) is produced in significant amounts. Nevertheless, the use of RAP is limited due to the absence of laboratory and field performance data. This research addresses laboratory and field tests to evaluate the use of RAP and various adapted mixtures in constructions such as road-bed layers and substitution layers. Modified proctor compaction, California bearing ratio, unconfined compression test, and static plate loading tests have been conducted on RAP, a mixture of RAP and crushed stone aggregates (CSA), and RAP stabilized with cement to satisfy the objective. Results have shown that 100% RAP material is suitable for use as a sub-base material. The ability of RAP material to be utilized as a cement-treated base layer is more pronounced when it is stabilized with cement (100% RAP + 8% and 10% cement). Utilization of 100% RAP stabilized with cement has been demonstrated to be economical in comparison with 100% CSA without cement. Finally, RAP material has shown good performance as a substitution layer.