Discarded Tires in Highway Construction - Construction Report Author(s): Mellott, Dale, Pennsylvania DOT Origin: Pennsylvania Date: May, 1981 Categories: Performance Key Words: SAMI, stress-absorbing, membrane interlayer, rubber-asphalt Summary: This report covers the construction of two stress-absorbing membrane interlayer (SAMI) projects in Pennsylvania. The SAMI material consisted of either an AC-20 or H-1 class asphalt with 33 percent granulated, reclaim rubber added. Different contractors, using slightly different processes, applied the SAMI at the two sites. Both project an additional two inch layer of ID-2 binder course material was placed directly on the SAMI and beneath theID-2 wearing surface course material. These projects had control sections that were constructed without SAMI for comparison purposes. These control sections were selected and placed randomly throughout the project.