The ¾-inch overlay is designed with low aggregate count - 100% of material has to pass through a ½-inch sieve.
According Jim Johnson, project engineer, the ultra thin mix specified for the project is a commercial ADT (average daily traffic) design requiring a PG 64-28 polymer modified binder. The MDOT commercial ADT mix is designed for average daily traffic counts of up 3,400 commercial vehicles.
"It's a surface rating and not a subbase requirement," Johnson notes. "Three years ago MDOT used the same ultra-thin mix on a county road used as a detour and they liked how well it held up. So that's what was specified for this project.
Without the stimulus funds, it's unlikely Stronach Road would have been completed this year.
"The road commission did complete a similar Hot In-Place/ultra-thin overlay project on a 3 1/4-mile road earlier this summer and had identified Stronach Road as an ideal candidate for the process, but the funding was just not there," Mikula says. "The total project was estimated to cost $482,000 and without the $190,000 stimulus funds received, there's no way we could have moved forward with the work this year."
Of ARRA's $27.5 billion allocated for road and bridge projects, MDOT expected to qualify for $850 million. Through the Small Urban Program, MDOT determined that approximately $12.9 million would be available to fund small projects similar to the Manistee road preservation completed this fall.
According to all the parties involved in the preservation project, there was some additional documentation required for the stimulus funding, but the funds received proved to be very beneficial in turning the project into a reality.