ASPHALT RUBBER 2000 Summary of the Conference About 220 Registrations About 185 Attendees 33 Countries 40 Papers Site Visit to Crumb Rubber Factory and Construction Site

Dispel the Myths about Asphalt Rubber (with 20% crumb rubber - wet method) Field Performance –Way, Shatnawi, Potgieter, Van Heystraeten, Watkins Cost Effectiveness –Watkins, Way, Hicks Environmental Effects and Benefits –Turner, Carlson

Other Areas Covered Laboratory Comparisons of Performance –Different Materials Presented Binder and Mix Testing –Different Materials Presented Accelerated Pavement Testing –Different Materials Presented (Most of the times laboratory results were in line with field observations; however occasionally laboratory results and conclusions did not correlate with field observations) More Research!

Functional Properties Skid Resistance Noise Reduction Texture

“Asphalt Rubber”? Wet Method (with 18-22%) Wet Method (15%) Wet Method (10%) - Terminal Blend Wet Method (5% + SBS) - Terminal Blend Wet Method (3.5%) - Terminal Blend Dry Method - 1, 2, 3% of aggregate mass - Short and Long Reaction times Proprietary Methods (no technical info!)

No evidence presented that ADOT or CALTRANS method (wet method with % crumb rubber) cannot be implemented and used in most parts of the world (on the contrary!)

“Gap-graded”? The Americans have started misusing this term to describe a grading similar to an SMA or open-grading. Be alert to this fact when reading US literature.