Lengthening road life has been a priority for road construction engineers and paving contractors to prevent road damage caused by longitudinal joint cracking. That is why we have created J-Band®, a void reducing asphalt membrane (VRAM) or as it is referred to in Illinois, longitudinal joint sealant or LJS.
How it Works
J-Band is applied prior to the paving process as part of the normal hot-mix asphalt (HMA) construction process, and it prevents or reduces required maintenance later in the future. To apply, an inline parallel spray bar is used to cover an 18-inch-wide area with J-Band at the longitudinal joint before paving. Once applied, J-Band is non tracking in less than 30 minutes. This allows the installation process to proceed quickly and keeps traffic flowing.
A Partnership Helped Develop J-Band®
In 2000, the Illinois Department of Transportation (IDOT) recognized a need for a new solution to improve the longitudinal joint on US-51 and other Illinois roads. Often longitudinal joints fail due to the high permeability in the joint area, allowing water to accelerate damage. This reduces the strength of the joint and causes cracking and potholes in roadways. IDOT reached out to Asphalt Materials (AMI) and Heritage Research Group (HRG) to find the best long-term solution.
HRG researched and developed a product called J-Band, to better improve the weakest part of the road, the longitudinal joint. In 2002, AMI’s VRAM product J-Band was introduced to IDOT. On September 4, 2002, in conjunction with IDOT a team from AMI and HRG completed a J-Band demonstration project on US-51 north of Elwin, Illinois. This was one of the first demonstration projects where J-Band was applied on test sections and was comparted with control sections that were constructed without J-Band and it was clearly mapped and marked for future evaluations.
J-Band was placed in 12 and 18-inch-wide strips of material approximately ¼ inch thick in various test sections. The sections were placed on a HMA level binder course below the location of the center line joint in the HMA surface course.
Following several case studies, IDOT reviewed the performance of J-Band with AMI in 2013. AMI then formulated, developed specifications, addressed application methods, and developed production capabilities. In 2015, AMI and HRG developed a spray application method to improve upon the previous application method. It is clear in the photos shown below that J-Band performed exceptionally well, and protected the most important part of the road, the longitudinal joint.
Twenty-One Years Later
This year marks the 21st anniversary of the J-Band experimental project that occurred on US-51 in 2002. This project case study has proven that a 20-year pavement life can be achieved with the use of J-Band. Our team had the opportunity to observe the 20-year pavement and concluded that the pavement was still in good standing. The chosen control section allows our team to observe differences between the pavements with and without J-Band over time. The control section shows many potholes that were filled multiple times and joints that were in poor condition.
