Evaluation of a 100 % rap recycling project in Fort Wayne, Indiana

Abstract

A project site investigation involving a high RAP (close to 100 %) recycling has been evaluated to determine the performance differences with a control section, located in Fort Wayne, Indiana, one year after construction. The analysis involved cutting cores from the surface and determining recovered binder properties and mixture physical properties. Binder properties included standard PG grading in accordance with AASHTO M320 and the development of full master curves over the range of temperatures -30 to +80 °C. From the master curve analysis was conducted to look at parameters such as cross-over frequency, rheology index and viscos-elastic transition temperature. The data from this testing has been used in a manner to judge the effectiveness of a recycling oil, particularly when inspecting the relationship between cross-over frequency and rheological index. Mixture testing included evaluation of strength properties by conducting tests in bending beam rheometers and the development of mixture master curves. At the current time little difference is seen in the performance of the 100 % RAP section compared to the control section, which provides significant support for continuing the effort to develop technologies for high percentage RAP recycling projects.