Using reclaimed asphalt pavement (RAP) offers several key benefits to producers and mix designers looking to trim costs from their mixes while delivering performance/specification requirements. Importantly, increasing the amount of RAP in a mix can reduce the need for virgin bitumen and aggregates. Using RAP also helps to reduce waste and, and durable, RAP-based roadway surfaces can support sustainability by reducing the carbon footprint of their mixes. 

 

Why Use an Asphalt Rejuvenator? 

While asphalt is 100% recyclable, there are limits to the amount of RAP that can be incorporated into a mix without using an asphalt rejuvenator or recycling agent. This is because while the aggregate in the RAP does not change with age, the binders oxidize, changing both physically and chemically. This can result in stiffer, more brittle mixes that are not long lasting, durable, or high performing when used as roadway surfaces. 

 

The key is to rejuvenate the aged RAP binder to restore the functional properties of the aged bitumen. Asphalt recycling agents can also reduce viscosity and rebalance the aged bitumen in a RAP mix.  

 

Different Types of Asphalt Rejuvenators 

A wide selection of rejuvenators are available, categorized by the materials they are formulated from.  

 

Different types of asphalt rejuvenators can include: 

  • Petroleum Based  
  • Used Cooking Oil 
  • Soft Bitumens  
  • Used Motor Oil 
  • Bio-Based Oils 

 

4 Factors for Choosing the Best Asphalt Rejuvenator 

Selecting the right rejuvenator for a RAP mix is important in order for the final asphalt mix to achieve required performance specifications. While many rejuvenators are designed to reverse the impact of oxidation on aged bitumen, not all products work the same way or produce the same results. When evaluating rejuvenators to find an effective or ideal asphalt recycling agent, consider these four factors. 

 

  1. Bitumen Softening

An ideal asphalt rejuvenator will help soften the aged bitumen in a RAP mix. This can help make the binder more flexible and able to penetrate and coat the aggregate more fully. Notably, not all softeners are rejuvenators. Dedicated softeners can help to reduce viscosity within the mix, but they may not rebalance the aged, oxidized binder or restore its functional characteristics.  

 

  1. Grade Adjustment

Effective asphalt rejuvenators will also adjust the bitumen grade within a RAP mix. A positive impact on PG high-temperature can reduce the occurrence of rutting or other deformations in a roadway surface. PG low-temperature adjustment can improve cracking and fatigue resistance through improved flexibility in a mix.  

 

  1. Compaction Improvement

The ability to compact a RAP mix while achieving desired air voids is another feature of an ideal rejuvenator. The recycling agent, in part, restores the workability of the aged binder, adding flexibility to the overall mix. This can result in the aggregate particles being able to move past one another more easily, improving compaction and reducing air voids. A rejuvenator that aids compaction can help produce a roadway surface with more uniform structure and reduced need for future repairs.  

 

  1. Durability Enhancement

Restoring the functional properties of the aged bitumen in RAP can ultimately result in the roadway pavement’s ability to bear heavy traffic, withstand extremes in weather conditions, and maintain its overall performance over time. Rejuvenators that improve durability also help extend the life of a roadway, further cutting costs and environmental concerns associated with frequent repairs and maintenance.  

 

ReLIXER®: Ideal Asphalt Rejuvenator for RAP Mixes 

When it comes to softening, grade, compaction, and durability, ReLIXER stands out as an ideal asphalt rejuvenator for RAP mixes. Formulated from a blend of green bio-based oils with no effect on food sources, ReLIXER not only restores the functional properties of aged bitumen in RAP but also lowers greenhouse gas emissions and carbon footprint impact.  

 

ReLIXER is also: 

  • Highly dosage efficient 
  • Easy to use at a mix plant 
  • Non-hazardous and safe to handle 
  • Compatible with a wide range of bitumen and RAP 

 

With over a decade of proven results, ReLIXER continues to help departments of transportation and producers achieve their RAP usage targets without sacrificing long-term performance.  

 

For more information about RAP, asphalt rejuvenation, and ReLIXER, contact info@sripath.com.