Pavement rehabilitation and reconstruction operations have generated large supplies of reclaimed asphalt concrete (RAC). In Illinois crushed RAC generally called recycled asphalt pavement (RAP) supplies are not 100 percent recycled into hot-mix asphalt concrete production. RAP acceptance as a pavement base material has been limited because of the lack of laboratory testing information, information on structural behavior, and field performance data. Limited preliminary laboratory testing and isolated commercial and local road agency paving experience in Illinois indicate that RAP has significant potential as a pavement base. RAP base potential was evaluated by constructing the Lincoln Avenue (Urbana, Illinois) demonstration project during late September and early October 1993. The pavement section is a 305-mm (12-in.) lime-modified, fine-grained subgrade, a 203-mm (8-in.) compacted RAP base, and a 76-mm (3-in.) dense-graded asphalt concrete surface course. The construction, structural response, and performance of the Lincoln Avenue RAP base project were monitored as part of a cooperative study (Illinois Department of Transportation, City of Urbana, and University of Illinois). The accumulated construction, field testing and evaluation, and laboratory testing data and information are summarized. The field construction experience, field control test data, laboratory testing results, falling weight deflectometer results, and Lincoln Avenue performance data indicate that RAP can successfully be used as a conventional flexible pavement base material. The performance of the Lincoln Avenue RAP base pavement (to date) is comparable with that of a crushed stone base.
Performance and Microstructure of Cold Recycled Mixes Using Asphalt Emulsion with Different Contents of Cement
