Laboratory Evaluation to Investigate the Effect of Compaction Energy and Moisture Content on the Mechanical Behavior of the Base Layer Containing Reclaimed Asphalt Pavement

This study has evaluated the unconfined compressive strength (UCS) of the cement-treated base (CTB) containing 100% reclaimed asphalt pavement (RAP) aggregates using different-age samples. The samples were prepared with standard and modified compaction energy based on ASTM D558 and ASTM D1557. Three cement contents of 4, 5, and 6 percent were added and the samples were cured for 3, 7, 28, 56, and 90 days after compaction. The unconfined compressive test has been carried out using the strain control method. In order to investigate the effect of moisture, in addition to the optimum moisture, moisture levels below and above the optimum have also been evaluated. Based on the results of this laboratory study, with the increase of cement percentage and curing period, unconfined compressive strength increase visibly. Next, indirect tensile strength (ITS) test was performed on the selected samples (mentioned ages) and the results showed that the curing period and cement directly affected and increased the tensile strength. Results indicated that the curing period and the compaction method had the greatest and least effect on the UCS, respectively. Finally, the UCS and ITS results showed that it is possible to use 100% RAP aggregates in the CTB layer.