Roadway durability has always been a key consideration for departments of transportation and municipalities initiating development or revitalization projects. However, existing road conditions continue to miss the mark as surfaces deteriorate over time. In the United States, 39% of major roads are considered to be in poor to mediocre condition, leading to costs for both DOTs and consumers alike. In the United Kingdom, road maintenance expenses via local authorities reached £4.8 billion in 2024. Globally, 67 out of 141 countries (47.5%) surveyed by the World Economic Forum exhibited a road quality score of 3.9 or lower, below the average of 4.07. 

 

Goals for new infrastructure projects are compounding the conversation surrounding existing roadway quality. The global market for road construction is projected to grow at a CAGR of 2.7% by 2030, representing $1.1 trillion. With development expected to take top priority through demand for urban expansion, the need for more durable asphalt pavements that can support budget, performance, and sustainability goals is on the rise. 

 

What is Durability in Asphalt Paving? 

A durable roadway is a paved asphalt surface that can maintain its integrity over extended periods of time while exposed to deteriorative conditions commonly caused by weather and traffic without requiring repair or maintenance. Durable asphalt surfaces maintain their functional characteristics for extended periods of time. Typical signs that a roadway is failing, or is not durable, can include: 

 

  • Cracking manifests as fractures in paved surfaces that can risk integrity through water infiltration and reduced load-bearing capabilities. Cracking can be caused by fatigue (i.e. repeated stress caused by traffic loads), temperature fluctuations, or issues with the base course of a roadway. 
  • Rutting appears as permanent deformation of the surface through depressions in a paved surface. Rutting is often caused by repeated traffic loads in roadway wheel paths indicative of poor compaction or shear strength.  
  • Raveling is the disintegration of a roadway surface over time as aggregate is worked loose from the roadway surface. Raveling can result from aging binder, poor compaction, and water damage coupled with repeated traffic abrasion.  

 

A durable asphalt paving solution produces a roadway surface that resists cracking, rutting, and raveling over time, reducing the need for repairs, maintenance, and resurfacing. 

 

How to Achieve Durable Asphalt Roadway Surfaces 

 

While many factors can jeopardize asphalt roadway quality, producers and mix designers can leverage several strategies to stave off typically deteriorating conditions on new surfaces. Best practices for durable roadways can include: 

 

  • Practice balanced mix design to address multiple performance specifications 
  • Treat all materials (aggregate, binder, RAP, additives, modifiers) with care 
  • Ensure uniform surface compaction 
  • Control mix temperature during construction 
  • Minimize cold joints between sections or lanes 
  • Implement proper water filtration and drainage methods 

 

Dosing mixes with polymers for asphalt can also help improve long-term performance of roadways. These paving solutions can help improve functional characteristics of an asphalt paving mix to enhance rutting, cracking, and raveling resistance while also resisting the impacts of aging. 

 

Improve Roadway Durability with PGXpand 

Importantly, not all additives are able to address the broad scope of performance specifications needed when designing an asphalt mix. Traditional elastomeric polymers may achieve good fatigue resistance but only acceptable rutting resistance. They also tend to require high shear mixing, long mixing times, and high mix and paving temperatures. Traditional plastomeric polymers can exhibit poor fatigue resistance while achieving good rutting resistance. Compared to elastomeric polymers, plastomeric polymers require medium shear mixing and mixing times; however, they still require high mix and paving temperatures. 

 

PGXpand® is different. A bitumen-friendly polymeric additive, PGXpand dosed mixes demonstrate both good fatigue resistance and excellent rutting resistance, leading to long-term durable roadway surfaces. In addition, PGXpand requires low shear mixing, short mixing times, and low mix and paving temperatures. PGXpand boosts high temperature performance, paving grade, and softening point without impacting low temperature properties. The additive is also dosage efficient, can help lower PMB costs through reduced energy consumption, and contributes lower CO2 and greenhouse gas emissions than traditional additives.  

 

For more information about Sripath’s commitment to safety, contact info@sripath.com. 

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