Asphalt continues as a cornerstone of road construction globally, with 90% of roads paved globally using asphalt. As infrastructure demands accelerate, environmental standards are also on the rise. However, traditional asphalt comprised of only bitumen and aggregate often falls short of modern expectations for performance, durability, and sustainability.  

 

Asphalt additives are purpose-designed materials that can elevate pavement performance to meet key specifications. Modern mix designs often incorporate one, if not more, of these additives to address challenges regarding pavement longevity, environmental impact, economic benefits, reduced maintenance, and working conditions.  

 

Why are Asphalt Additives Used? 

While asphalt can be a versatile material, its flexibility, strength, and longevity can be limited. These issues are caused by factors like varying quality of bitumen worldwide, increasing exposure to heavy traffic loads and extreme climate conditions, and growing demand for more sustainable ways to use asphalt.  

 

Asphalt additives were introduced to adapt and enhance asphalt mixes by offering benefits such as: 

  • Greater Durability: By improving resistance to rutting and cracking, additives may extend the service life of paved surfaces. 
  • Improved Workability: Some additives make binder production mixing, spreading, and compacting asphalt easier even in challenging conditions. 
  • Enhanced Sustainability: Some asphalt additives allow for carbon capture, lower mixing temperatures, and increased use of recycled materials, which can reduce energy use and environmental impact.  
  • Superior Performance: Enhanced toughness, elasticity, and compatibility with recycled content can help asphalt remain durable across a variety of conditions. 

Types of Asphalt Additives 

The landscape of asphalt additives is wide-ranging with several categories playing key roles in modern pavement design. Here are just a few asphalt additive categories that represent current performance demands in the paving industry.  

Polymer Modifiers 

Polymers such as elastomers and plastomers can enhance the elasticity, toughness, and temperature resistance of asphalt. These modifiers are often used in high-traffic areas such as highways and airports to ensure consistent performance and longevity. 

 

Asphalt Rejuvenators 

These additives restore the functional and rheological properties of the aged asphalt binder in mixes that incorporate reclaimed asphalt pavement (RAP). An ideal asphalt rejuvenator can help maximize recycled content without sacrificing pavement quality or durability. 

 

Warm Mix Asphalt (WMA) Additives 

WMA additives enable production, laydown, and compaction at significantly lower temperatures. This not only reduces energy consumption and greenhouse gas emissions but also enhances worker safety and extends the paving season. WMA technologies can include organic additives, chemical additives, and foaming techniques.  

 

Bitumen Softeners 

Bitumen softeners are additives designed to improve low-temperature performance of asphalt mixes. This can result in improved penetration, reduced stiffness, and lower binder PG grade to reduce potential for cracking. Bitumen softeners can also reduce the viscosity of asphalt binders, making the mix more workable during production and placement.  

 

Emulsifiers 

Used in the production of asphalt emulsions, these additives promote the blending of asphalt with water and enable cold-mix applications, surface treatments, and maintenance techniques. Emulsifiers also play a critical role in effective pavement preservation. 

 

Crosslinking Agents 

These chemical additives enhance the chemical interaction between polymers and bitumen. Crosslinking agents in PMB mixes can greatly affect the long-term performance of road surfaces. 

By forming stronger bonds within the asphalt binder, crosslinkers can improve resistance to deformation, rutting, and cracking. This can help extend pavement service life and improve durability. 

 

Sustainable, High-Performance Asphalt Additives 

Sripath develops asphalt additive technologies that prioritize both performance and sustainability. As the demands on modern infrastructure grow, the need for additives that deliver durability while supporting environmental goals has become increasingly important.  

 

Sustainable, high-performance additives can increase pavement longevity while also reducing the environmental footprint of road construction and maintenance. Recognizing these benefits, Sripath has developed a range of innovative additives designed to deliver both durability and sustainability across the paving industry. 

 

PHALANX®: Warm Mix Additive 

A specially engineered molecule and surface-active agent, PHALANX enables asphalt mixes to be produced, laid, and compacted at significantly lower temperatures, resulting in reduced energy consumption throughout the paving process. PHALANX-dosed asphalt mixes can maintain strength, flexibility, and longevity while minimizing energy consumption and greenhouse gas (GHG) emissions  

 

PGXpand®: Bitumen-Friendly Polymeric Additive 

PGXpand promotes high-performance PMB blends by enhancing high-temperature performance without impacting low-temperature properties. By improving performance grade, asphalt mixes dosed with PGXpand can better resist thermal and mechanical stress.  

 

ReLIXER®: Asphalt Rejuvenator  

ReLIXER is an asphalt rejuvenator or recycling agent that enables the use of high levels of reclaimed asphalt pavement (RAP) in mixes. ReLIXER restores the functional characteristics of the aged binder in RAP. This can extend the pavement life of high-RAP mixes and can reduce the need for virgin bitumen and aggregate, helping to lower costs and reduce environmental impact. 

 

ButaPhalt®: Crosslinking Agent 

ButaPhalt is a crosslinking agent designed to improve performance by enhancing the efficiency of sulfur-polymer interactions during Polymer Modified Bitumen (PMB) production. It offers improved thermal stability, lower hydrogen sulfide emissions, and superior dosage efficiency compared to traditional crosslinkers. ButaPhalt streamlines production to help producers achieve targeted PMB grades while reducing operational costs and processing time. 

 

NuMIXER® & ReNUBIT®: Bitumen Softeners 

NuMIXER and ReNUBIT are both effective bitumen softeners designed to reduce viscosity and enhance polymer compatibility. NuMIXER is a green blend of prime bio-based oils offering environmental benefits along with low temperature property enhancement and improved fracture toughness and fatigue resistance. ReNUBIT is a special blend of petrochemical oils that supports high filler loadings and delivers exceptional dosage efficiency.  

 

 

Asphalt additives are making it easier than ever for producers and mix designers to innovate their formulations and meet specifications. The result can be stronger, more adaptable, and environmentally responsible roadways.  

 

To learn more about asphalt additives from Sripath, contact info@sripath.com. 

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