Hot-in-Place Recycling for Asphalt includes milling existing pavement, adding an asphalt rejuvenator, and mixing onsite.

Hot-in-place recycling (HIR) has emerged as a practical approach for highway agencies and contractors to reduce costs, conserve materials, and meet sustainability goals. This asphalt recycling technique restores existing pavement directly on the roadway, minimizing material waste and reducing the environmental footprint of rehabilitation projects.  

 

When paired with an asphalt rejuvenator like ReLIXER®, HIR can deliver high-performance results while enabling greater use of recycled asphalt materials, incorporating 100% reclaimed asphalt pavement (RAP) through in-place recycling. 

 

What is Hot-in-Place Recycling (HIR)? 

Hot-in-place recycling (HIR) is an asphalt recycling process that rehabilitates distressed asphalt pavement by heating, milling, rejuvenating, and repaving the existing material all while onsite at the roadway. Rather than removing the material, processing the mix at a plant, and returning later to replace the pavement, HIR reuses the original asphalt binder and aggregates in place to build a new roadway surface.  

 

A typical hot-in-place recycling process for asphalt roadways involves: 

  1. Heating the existing pavement to soften the aged asphalt binder 
  2. Scarifying or milling the surface layer 
  3. Adding rejuvenators or recycling agents to restore binder properties 
  4. Mixing and leveling the recycled asphalt material 
  5. Compacting to create a renewed pavement surface 

 

This continuous, in-place process makes HIR one of the most efficient forms of asphalt recycling available. 

 

Why Hot-in-Place Recycling Matters 

Aging pavements are often structurally sound but suffer from surface-level deterioration caused by oxidation, traffic loading, and environmental exposure. Traditional mill-and-overlay approaches can be costly and resource-intensive, especially when full material and base course replacement may not be necessary. 

 

Hot-in-place recycling offers a way to extend pavement life while conserving natural resources. By reusing existing materials, this method reduces demand for virgin aggregates and asphalt binder, which can be energy intensive to produce and can tax natural resources. For agencies focused on lifecycle performance and sustainability, HIR can provide a balance between performance and environmental responsibility. 

 

Key Advantages of Hot-in-Place Recycling 

Hot-in-place recycling delivers a range of economic, operational, and performance benefits: 

  • Material conservation: Reuses existing pavement materials to reduce reliance on virgin resources 
  • Lower hauling and production emissions: Minimal transport of materials compared to traditional paving 
  • Reduced project costs: Less raw material and faster construction timelines 
  • Traffic disruption minimized: Continuous process allows roads to reopen more quickly 
  • Improved pavement performance: Restores flexibility and durability to aged asphalt 

 

Because HIR incorporates high percentages of recycled asphalt, it can play a significant role in advancing recycled asphalt technologies and practices. 

 

HIR and Sustainability in Asphalt Recycling 

Sustainability is one of the strongest arguments for hot-in-place recycling. By keeping materials on-site and reusing existing pavement materials including binder and aggregates, HIR can significantly reduce greenhouse gas emissions associated with material production, transportation, and disposal. 

 

When considering a circular economy perspective, HIR represents a closed-loop approach to asphalt recycling. This is because existing pavements become the feedstock in the rehabilitation process. Hot-in-place asphalt recycling can reduce landfill waste and align with goals to maximize recycled asphalt use while maintaining performance standards. 

 

Additionally, HIR often requires lower production temperatures than traditional hot mix asphalt processes, contributing to energy savings and reduced emissions during construction. 

 

The Role of ReLIXER in Hot-in-Place Recycling 

While heating and remixing reclaimed pavement is effective, aged asphalt binder requires rejuvenation to ensure long-term performance. This is where ReLIXER asphalt rejuvenator becomes a seamless and valuable part of the HIR process. 

 

ReLIXER is specifically designed to rejuvenate binder in RAP and restore the functional properties of the aged bitumen. When incorporated during hot-in-place recycling, ReLIXER: 

  • Restores functional balance to aged bitumen in RAP 
  • Supports higher effective use of RAP 
  • Provides stability at mix and use temperatures 
  • Lowers GHG and overall carbon footprint  

 

Because HIR relies heavily on existing materials, the ability to enable high recycled asphalt content without sacrificing performance is critical. ReLIXER allows contractors to confidently maximize RAP usage while delivering pavements that meet performance expectations. 

 

Enabling High RAP Content with Confidence 

One of the ongoing challenges in asphalt recycling is balancing sustainability with pavement longevity. High RAP content can introduce stiffness and brittleness if the aged binder is not properly treated. In HIR applications, ReLIXER helps overcome this by effectively restoring the functional balance of the binder rather than simply softening it. 

 

The result is a recycled asphalt mix that behaves more like a virgin binder system and supports durability, flexibility, and long-term performance. This makes ReLIXER an ideal fit for hot-in-place recycling projects focused on sustainability without compromise. 

 

A Smarter Path Forward for Sustainable Paving 

Hot-in-place recycling is a field-proven solution for pavement rehabilitation. By combining efficient construction practices with advanced asphalt recycling technologies, HIR can help extend pavement life, reduce costs, and meet environmental goals. 

 

When dosed with ReLIXER asphalt rejuvenator, hot-in-place recycling becomes an even more powerful tool—enabling higher recycled asphalt use, improved performance, and a more sustainable paving future. 

 

As the industry continues to prioritize recycled asphalt solutions, HIR stands out as a practical example of how innovation and sustainability can work together—right where the pavement already exists. 

 

 

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

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