Description
To evaluate the effect of different mixing times and mixing temperatures of the visco-elasctic behavior of asphalt rubber binder a total of six different types of asphalt rubber and conventional asphalt binders were tested. To quantify the percentage of crumb rubber particles digestion in asphalt cement after mixing with a 45 minute reaction time, asphalt rubber binder, prepared in the laboratory and field produced samples were tested by extracting crumb rubber for rubber binder The test results of crumb rubber extracted indicated over 91% of the crumb rubber recovered from the asphalt rubber binder samples obtained from the laboratory and field produced samples. The recovered crumb rubber particles gradation was the same as the crumb rubber gradation before mixing and reacting with asphalt binder. There was no swelling of recovered crumb rubber realized. The test results of viscosity, penetration, resilience and softening points on field produced asphalt rubber binders indicates that: the increased viscosity of the asphalt binder rubber is reversible after crumb rubber was separated from the asphalt rubber binder therefore Crumb rubber in asphalt rubber binder acts as an additive not as a modifier.