FLEXIBLE PAVEMENT REHABILITATION USING ASPHALT-RUBBER COMBINATIONS: PROGRESS REPORT

Several flexible pavement rehabilitation strategies incorporating asphalt-rubber were used experimentally on a project in northeastern California in the fall of 1983. Included were rubberized dense-graded asphalt concrete (AC) overlays containing a binder then being marketed by the Arizona Refining Company, PlusRide dense-graded AC overlays, and four thicknesses of conventional dense-graded AC overlay for comparative evaluations. Some of the rubberized dense-graded AC overlays were placed on a stress-absorbing membrane (SAM) interlayer. In addition, two sections of double SAM and one section of conventional (single) SAM were placed. Distress began to develop in the conventional dense-graded AC within one year in the form of raveling, rutting, and cracking. This distress has become more extensive and more severe during subsequent years. Distress has also developed in the other overlays and surface treatments. To date, however, all the asphalt-rubber combinations are performing equal to or better than equivalent or greater thicknesses of conventional dense-graded asphalt concrete.