Rubber-Modified Asphalt-Concrete Overlays: A Summary of Field Performance Author(s): VanBramer, Thomas F. Origin: New York Date: May, 1997 Categories: Performance Key Words: Waste tire rubber Summary: In 1987, the New York State Legislature directed the DOT to undertake a pilot project demonstrating the use of waste-tire rubber in construction or improvement of state highways. This resulted in building two test roads in the summer of 1989, using various percentages of rubber as an aggregate incorporated into asphalt-cement-concrete pavement, by what is commonly called the “dry process.” Each site consisted of five 2000-ft. test sections: three containing 1-,2-, or 3 % rubber by total weight of the mix; a fourth with a conventional mix used as a control. This report covers the conclusion of that study, addressing the issues of service life and performance of these rubber-modified asphalt concrete (RUMAC) pavements over a 5-year period. Performance was recorded semi-annually and types and locations of distress where documented. Falling-weight deflectometer tests, laboratory analyses, and other field tests were also conducted. Results from this study indicate that RUMAC pavements, as designed from the job-mix formulas used here, did not perform as well as conventional mixes.