This report describes the construction of asphalt pavements made with three types of asphalt binders. The three types of binders were PBA-6, PBA-6GR (ground rubber), and AR4000W. The two modified binders, PBA-6 and PBA-6GR, are being evaluated to determine their resistance to rutting as compared to the conventional binder, AR4000W.
Construction was not without problems. Cyclic segregation, defined as repetitive areas of asphalt mix segregation that occur at approximately every truck load, was a major problem on the northbound lanes. A material transfer device was used on the southbound lanes which minimized the cyclic segregation effect.
At the time of this report (approximately two years and 1.0 to 2.0 million ESALs), there is no data that indicate which of the three asphalt binder types will have better performance. The project will be monitored over the next five to ten years to identify if any added performance is gained in any one of the mixes.
Washington (State). Dept. of Transportation. Materials Laboratory.
Asphalt, Asphalt rubber, Binders, Bituminous binders, Mechanical analysis, Paving, Performance evaluations, Rutting, Segregation (Aggregates)