TRANSCRIPT FROM VIDEO: Reclaimed Asphalt Pavement is sourced from older, weathered, and worn roadway surfaces. Because of this, the materials in the RAP, particularly the bitumen, age and lose some of their chemical and physical properties. As the binder oxidizes over time, the material can become brittle. This is what causes the roadway performance to fail. To [...]
TRANSCRIPT FROM VIDEO: The approach used depends on the specifications adopted for liquid binders in a given jurisdiction, country, or region. Some locales will set softening point and penetration specs, some will use binder viscosity specs, and yet others may rely on performance grade specs. In all cases, rejuvenator dosage is determined by blending virgin binder, extracted [...]
TRANSCRIPT FROM VIDEO: There are several approaches to evaluating RAP in balanced mix design. Balanced mix design considers the functional characteristics of the mix and seeks a compromise between competing properties in order to meet the required specifications for roadway performance. For example, a balanced mix design will look to offset the impact of stiffness compared to [...]
TRANSCRIPT FROM VIDEO: Asphalt mixes incorporating RAP should be evaluated for key performance specifications. To do this, samples from the fractionated RAP stockpiles are taken to a lab for analysis. Determining the amount of RAP viable in a balanced mix design will depend on the established mix specifications. Typically, by using a blend from different fractionated particle [...]