In modern roadway construction, the choice of polymeric additives plays a critical role in balancing performance, and workability. Traditional elastomeric and plastomeric polymers have long been used to enhance asphalt binders when developing polymer modified bitumen (PMB) mixes. However, advancements in polymer technology, such as the introduction of bitumen-friendly polymeric additive PGXpand®, are reshaping how engineers approach high-performance paving solutions. 

 

Understanding Traditional Polymers for PMB Development 

Elastomeric Polymers 

Elastomeric polymers are valued for their good fatigue resistance and elastic recovery. They can offer a durable solution for roadways subjected to repeated traffic loads, making them a reliable choice for high-traffic applications. Rutting resistance with elastomeric polymers is generally acceptable, but achieving optimal performance requires careful attention to the mixing process. High-shear mixers, extended mixing times, and high temperatures during both mixing and paving are necessary to fully integrate these polymers into the asphalt mix.  

 

Elastomeric polymers also require the use of crosslinking additives to ensure polymer functionality. They can also require warm mix additives to facilitate workable paving conditions. While elastomeric polymers can be effective, these requirements can increase energy use and processing time, adding to costs and reducing any efforts toward sustainability.  

 

Plastomeric Polymers 

Plastomeric polymers are designed to enhance rutting resistance, which is particularly valuable in regions with high ambient temperatures or heavy load traffic. However, these polymers tend to have poor fatigue performance, which may compromise long-term pavement durability. Plastomeric polymers can be slightly easier to process than elastomerics, requiring medium-shear mixers and moderate mixing times. They do still require high temperatures during mixing and paving. Unlike elastomeric polymers, they typically do not require crosslinking additives, though warm mix additives may be necessary to optimize paving conditions. 

 

PGXpand: A Bitumen-Friendly Polymeric Additive 

PGXpand represents an innovation in hot mix, PMB, and other asphalt applications. A bitumen-friendly polymeric additive, it is designed to simplify asphalt production while enhancing roadway performance. PGXpand delivers excellent rutting resistance while maintaining strong fatigue performance, providing a balanced solution for both durability and high-temperature deformation.  

 

One of the key differentiators of PGXpand is its workability. Unlike traditional elastomeric or plastomeric systems, it requires only low-shear mixing and significantly shorter mixing times, reducing energy consumption and production complexity. Additionally, PGXpand allows for lower mix and paving temperatures, supporting more sustainable and safe construction practices by decreasing fuel usage and lowering greenhouse gas emissions associated with high-temperature, high-energy asphalt production. The asphalt additive also eliminates the need for crosslinking agents or warm mix additives, further streamlining operations and expenses.  

 

The decision between elastomeric, plastomeric, and advanced additives like PGXpand involves consideration of production and performance factors. Traditional polymers may remain suitable for specific scenarios where their strengths align with project requirements, but the operational complexity and energy demands can be limiting. PGXpand offers an alternative that combines outstanding performance outcomes while helping to simplify processing and offering a more sustainable alternative. 

 

 

For more information about polymer modified bitumen, polymer additives, and PGXpand, contact info@sripath.com Â