VinexRap Series - Asphalt Rejuvenating Agents

 

The function of the rejuvenating agent is to modify the properties of the aged binder contained in the RAP so that the recycled asphalt has properties resembling those of the original asphalt. It may not be possible to restore the asphalt to its former state, but it should be possible to significantly improve those properties that have been subject to deterioration.

 

 

 

AGEING OF BITUMINOUS ROAD SURFACES

 

Asphalt roads deteriorate over time due to the impact of traffic, water and sunlight. The deterioration in road quality can lead to permanent deformation or rutting, cracking or brittleness and can lead to inferior skid resistance. The deterioration is evident from a decrease in penetration value of extracted bitumen binder and an increase in softening point.

 

SOLUTIONS

 

Recycling techniques offer a means of recovering desirable road construction bitumen properties without replacing the entire pavement with new materials. They enable reuse of production waste from the asphalt road industry. Recycling asphalt roads has the advantages of decreasing the demand for natural resources, decreasing the production of waste material and reducing costs. Desirably the amount of the asphalt road that is recycled is maximised and the amount of new material that is added to the recovered asphalt is minimised.

 

Reclaimed asphalt pavement (known as RAP) can be recycled "in-place" (i.e. at the road location), or can be recycled "in-plant" (i.e. the RAP is removed from the road surface and transported to an asphalt mix plant) . In a hot in-place recycling process, the existing road is reheated and milled and virgin aggregate and a rejuvenating agent are added to the RAP. This process is primarily used for resurfacing the top layer of a road and can re-use up to 100% of the RAP. In a hot in-plant recycling process, the RAP is crushed, milled, screened, and virgin aggregate, a rejuvenating agent and, in some instances, fresh bitumen are added.