About This Project:
A project utilizing VRAM took place on IL-49 in Vermillion County, Illinois on September 27th. This was a 14.5-mile, two-lane project. It began on the southern end at US-150 west of Fithian, ending at US-136 on the northern end. IDOT designated VRAM for the application to the centerline joint prior to the final HMA paving. (Note: in Illinois VRAM is often referred to as LJS).
This was an Illinois Department of Transportation (IDOT) project.
The VRAM applicator for this project was Illiana.
The prime paving contractor for this project was Cross Construction.
The application band width for the VRAM on this project was targeted to be 18” wide and applied to the centerline joint over existing binder. The project started at the US-150 intersection in the northbound lane and continued heading northbound. The paving occurred shortly after the application of the VRAM.
Asphalt Paving Operation
The paving process began a few days after the VRAM was applied. The paving equipment used for this project consisted of:
- A Cedar Rapids CR662RM MTV
- A CAT AP1055F paver
- A Hamm HD-120i – 12-ton and CAT CB13 – 12-ton breakdown rollers working in tandem
- A CAT pneumatic – 15-ton intermediate roller
- A Hamm HD-110i– 10-ton finish roller.
The breakdown rollers were making 3 vibratory passes along with 5 passes with the intermediate roller. The paving began in the southbound lane going southward at a width of about 13 feet. After the paving was complete, the project came to a successful close!
VRAM is a Materials Approach that Improves Longitudinal Joints
When VRAM is applied at the time of construction under the surface of HMA, it will reduce the permeability in this critical area of the road. Once the placement of the hot mix asphalt (HMA) is complete, heat causes the VRAM to physically migrate upwards, resulting in the filling of voids and reducing permeability.
An illustration of the VRAM material migrating upwards once the hot mix asphalt is put down. This action results in the filling of voids with asphalt material from the bottom-up.
States Continue to Find Success with VRAM
An increasing number of agencies, companies, organizations, institutes, and governing bodies are embracing principles of sustainability in managing their activities and conducting business. Historically, sustainability referred to environmental sustainability and simply meant using natural resources in a way that people in the future could continue to rely on their yields in the long term.
Long service life is one of the primary drivers of pavement sustainability. Asphalt pavements with longer design life offer the opportunity to reduce lifecycle costs, user delays (safety), and environmental impacts compared to a standard 20-year pavement design.
The Wisconsin Highway Research Program/Department of Transportation conducted a study on Void Reducing Asphalt Membrane (VRAM) to identify the benefits of including this step in the paving process.
Based on published data and review of case studies, implementing Void Reducing Asphalt Membrane (VRAM) during the construction process is recommended. Post-construction, it is recommended to use penetrating asphalt emulsions as a preventative and remedial treatment for longitudinal joints.1
To read about other VRAM studies you can follow this link. https://thejointsolution.com/resource/studies/
SOURCES:
1 https://wisconsindot.gov/documents2/research/0092-21-05-research-brief.pdf
Editor’s Notes:
Centerline joints and longitudinal joints are often used interchangeably in describing the area of the pavement where two paved sections come together.
VRAM, Void Reducing Asphalt Membrane is referred to in Illinois as LJS, Longitudinal Joint Sealant.
Depending on the situation VRAM can be sprayed at different widths. It should be noted that 18” is a typical application width for centerline applications.
J-Band® is a VRAM product of Asphalt Materials, Inc. that was created in the labs of The Heritage Research Group.
J-Band®, CCAP® and T-Bond® are registered trademarks of Asphalt Materials, Inc.
AMIBIND™, AMIBOND™, AMICYCLE™, AMIGUARD and AMISEAL™ are trademarks of Asphalt Materials, Inc.
