After decades of testing, J-Band®, the premier Void Reducing Asphalt Membrane (VRAM) from Asphalt Materials Inc. (AMI), is the proven innovation that dramatically reduces the age-old problem of longitudinal joint deterioration. Take a look back with us at one of the first projects to incorporate this game-changing asphalt product.

Premature cracking and potholing often first occur along the longitudinal joints of pavement. Because this area often has a higher percentage of voids, water more easily seeps in and causes damage. Especially in climates that experience multiple freeze-thaw cycles in a season, keeping water out of pavement is key to extending the life of a road. 

AMI took a materials-based approach to protecting longitudinal joints. J-Band®, a highly polymer-modified asphalt membrane, was engineered to keep air and water out of pavement and increase density and compaction around the joint – so it can stand the test of time. 

Watch the US-51 video case study to see the success J-Band has had on extending pavement life.

US-51 Project History 

The 2002 J-Band application on US-51 was one of J-Band’s first major demo projects. Two years prior, the Illinois Department of Transportation (IDOT), Asphalt Materials, Inc. (AMI) and Heritage Research Group (HRG) worked together to find an alternative solution for the recurring issue of longitudinal joint failure. HRG developed a new asphalt technology, the void reducing asphalt membrane (VRAM), which Illinois refers to as a longitudinal joint sealant (LJS). As the premier VRAM, J-Band significantly reduces voids and permeability in the longitudinal joint from the bottom up — literally.  

For this experimental project just south of Decatur, Illinois,  J-Band was sprayed in four 100-ft test sections. These test sections were interspersed with clearly marked control sections, so the joint’s performance could be evaluated year over year.  

Project Details  

  • Owner: IDOT  
  • Prime Paving Contractor: Illinois Valley Paving  
  • J-Band Applicator: Emulsicoat, Inc.   
  • Location: US Route 51, Elwin, IL in Macon Co.  
  • Date Constructed: September 2002  
  • Dates Reviewed: 2013, 2017, 2019, 2022  

Application Process 

J-Band is applied as part of the normal HMA construction process. It is sprayed before HMA paving in a band, usually 18” wide, on the existing binder course where there will be a longitudinal surface joint or rumble strip. It can be applied thick without running and is non-tracking within 30 minutes, allowing construction traffic to keep moving. The heat from the final lift of HMA pavement and the pressure of the rollers cause J-Band to migrate up into the voids at the longitudinal joint. This significantly reduces permeability so the joint can last as long as the rest of the pavement. 

Project Review 

When US-51’s test site was reviewed in 2013, the impressive condition of the joint with LJS/VRAM prompted IDOT to develop a specification adding LJS/VRAM to future paving projects. AMI’s VRAM product, J-Band, meets this specification.  

The US-51 project has also been reviewed in 2017, 2019 and 2022. Even 20 years after the initial application, the difference in performance between the J-Band and control test sections can be seen in the images below. Without J-Band, the centerline experienced severe deterioration, with prevalent potholes that were filled on multiple occasions.   

The Proof is in the Pavement 

Lab testing of cores taken from the US-51 centerline showed that the use of a VRAM decreases pavement permeability by increasing the asphalt content. Density was measured at an average of 3-5% higher for cores from the VRAM test sections. Additionally, I-FIT testing found that VRAM cores had about 28 times higher cracking resistance than control cores. 

From lab tests to visual evaluation, the US-51 project is proof of how J-Band can preserve longitudinal joints for over 20 years. With a VRAM in place, agencies can eliminate their typical longitudinal crack sealing every 3-5 years, which is safer for workers and the motoring public. By extending the life of pavement and deferring maintenance costs and risks, J-Band is saving time, money and lives.  

Resources 

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