Illinois Performance Study of Pavement Rubblization

The majority of the pavements on state routes in Illinois were originally constructed of portland cement concrete (PCC). Many of these pavements have been rehabilitated or are in need of rehabilitation. Historically, the most common rehabilitation method has been patching of deteriorated areas followed by an overlay with bituminous concrete. Bituminous overlays of PCC pavements usually begin to fail at the reflected joints and patched areas of the old concrete pavement, as well as in areas where the underlying concrete has continued to deteriorate. In 1990, the Illinois Department of Transportation (IDOT) began experimenting with rubblization as a method for rehabilitation of PCC pavements. Rubblization transforms the existing pavement into a high quality aggregate base, thus eliminating joints and cracks that may reflect through the bituminous overlay. This paper provides a history of rubblization in Illinois, including factors used in project selection, types of rubblization equipment used, and construction sequence. Design details of experimental sections and a summary of each project's performance are described. Twelve projects using the rubblization method have been constructed on state routes in Illinois, eight of which have been closely monitored. To date, all rubblization projects constructed in Illinois have performed as well as, or better than, control sections.