BEgreen™ RAP

Reclaimed asphalt pavement (RAP) is recycled at a greater rate than any other material in the United States. But this is misleading because RAP does not have the same properties as virgin asphalt.

In 2019, new asphalt pavement mixtures produced in the United States contained, on average, 21.1% RAP.

During its service life, the asphalt cement binder, which makes up about 5 – 6% of a typical asphalt concrete mix, naturally hardens and becomes stiffer. This aging process primarily occurs due to oxidation, evaporation, exudation, and physical hardening. For this reason, asphalt mixes containing RAP are prone to exhibiting lower workability and increased susceptibility to fatigue cracking.

One approach to balancing the performance aspects of RAP is to combine recycled components with virgin aggregate and virgin asphalt binder. However, this approach can only be effective when the recycled content in the mix is relatively low due to variability in the quality of the RAP.

In mixes with higher recycled content, the addition of virgin binder becomes less effective, and rejuvenators must be used. Rejuvenators are additives that restore the physical and chemical properties of the aged binder.

When conventional mixing methods are used in asphalt plants, the upper limit for RAP content before rejuvenators become necessary has been estimated at 50%.

Research has demonstrated that the use of rejuvenators at optimal doses can allow for mixes with 100% recycled components to meet the performance requirements of conventional asphalt. Our process coupled with rejuvenators allows every drop of reclaimed bitumen oil to be used to make virgin quality asphalt.