IL 160 / IL 177 is a two-lane state road about 35 miles east of St. Louis. J-Band was scheduled to be applied at 18” wide at a rate of 1.47 lb./ft. on this project. Rodney, the AMI field support engineer on the job, reviewed the J-Band checklist with IDOT and the paving crew.

After being applied, J-Band cooled to 120°F in just four minutes. Traffic can typically cross J-Band at these temperature without tracking. The surface course for this job was an IL 9.5 C-mix N70, PG 64-22 compacted to 1½”.

J-Band was measured to migrate about 5/8” up into the HMA overlay prior to compaction. The total migration height after compaction is between 50-75% of the overlay height and will can be measured directly from core samples. Shadowing, but not flushing, was noted on this job. Shadowing is a characteristic sign that J-Band has migrated up into the HMA.

Although it’s too soon to see an obvious difference between a joint treated with J-Band and a regular joint, after a few tough Illinois winters, the difference should be evident. The J-Band team will monitor this project over the years to document how well J-Band performs.