Many of South Carolina's asphaltic concrete pavements have experienced stripping. It is not known whether these materials will experience stripping again if recycled. A laboratory and field study was initiated to evaluate the effects of reusing moisture-damaged asphaltic concrete, the recycled mix design procedures that use cored reclaimed asphalt pavement (RAP) instead of milled RAP, the effects of antistrip additives on recycled mixtures, and the ability of laboratory-prepared Marshall specimens (25 blows per side compaction effort)to predict certain characteristics of recycled asphaltic concrete pavement. A total of 144 Marshall specimens were made and tested. In addition, sixty-four 4-in-diameter and thirty-two 8-in-diameter field cores were obtained from a test pavement section before and after recycling. Both laboratory and field specimens (4in in diameter) were subjected to two moisture conditions (ie dry and wet) and tested for indirect tensile strength (ITS), resilient modulus (MR), visual strip rating, and air voids. Tunnicliff and Root testing procedures were used for moisture conditioning of specimens. Marshall specimens containing moisture-damaged asphaltic concrete mixtures obtained significantly higher TIS and MR values than those prepared with virgin materials. In addition, the results indicated that there were no statistical differences between ITS and MR of specimens prepared with cored RAP and milled RAP. Antistrip additives were found to be effective in improving the ITS and MR of specimens in the saturated condition.
Abstract