Preservation Key to Long-Range Strategic Investment

Michigan's Kent County Road Commission's Maintenance Division increases preservation efforts to maximize overall network investment.


During that same period, 45 cents out of every dollar spent by KCRC went to expanding the network, while 20 cents went to reconstructing existing roads, and 35 cents went to preserving and maintaining roads in good condition. Over the next 10 years, KCRC plans to increase funds for preservation projects (49 cents out of every dollar) to achieve a network with 70 percent of all primary roads in good condition. That will reduce the county's reconstruction needs to less than five percent.

Studies show that for every dollar spent on maintaining and preserving roads in good to fair condition the repair cost increases four to five times if the road drops to a poor condition rating. From 2002 through 2005, KCRC invested $202,000 to chip seal 362 primary and local miles within the network, and $262,000 to micro-surface 76.5 miles of primary and local roads.

During the same period, Kent County spent $72,500 per mile to apply an "ultra thin" hot-mix asphalt overlay to 10.5 miles of primary and local roads. The investment in preservation projects will continue to increase over the next 10 years in order to achieve and maintain a higher percentage of "good condition" roadways throughout KCRC's network.

Chip seal, micro-surfacing key preservation treatments

Chip seal contractor C and C Construction of Montgomery, MI was awarded the county's chip seal work for 2005, 2006 and 2007. Owner Chris Ruhl says his company has been placing approximately 1.3 million square yards of chip seal each year on county and residential roadways.

"The county purchases the material and stages it for the projects, and does a great job prepping the roads before we come in to do the work," Ruhl says. "We have two Etnyre spreaders, a couple of Etnyre distributor trucks, a 10,000-gallon stationary tanker, several rubber-tired rollers, and we just purchased a new 20-foot Bearcat spreader for next season.

With a crew of 15, including Ruhl, C and C handles the entire chip seal operation from applying the emulsion, spreading the natural stone, rolling the stone into the emulsion, trucking, traffic control and applying temporary lane markings.

"We work primarily in Southwest Michigan and Kent County has the most progressive road maintenance program in place compared to the other agencies we service," Ruhl says. "They have a pretty aggressive goal in achieving and maintaining a network of good roads, and we're happy to part of that plan."

As for micro-surfacing work, Ohio-based Terry Asphalt Materials Inc., a division of Barrett Industries Corporation, has been Kent County's go-to contractor for the past decade.

In the mid-1990s, Kent County wanted to use a preservation treatment that provided a smoother surface and would hold up to snow plows. The county uses micro-surfacing treatments for:

  • Rut-filling — Utilizing a rut box that re-profiles each individual rut when the rut depth exceeds ½ inch, the micro-surfacing application requires a 3FA aggregate and special mix design.
  • Two-course application — This application utilizes a conventional laydown box with a steel screed to level or scratch the first course to correct minor pavement defects, and the typical spread rate is 12 to 16 pounds per square yard. The surface course is then applied at a rate of 18 to 20 pounds per square yard.
  • Single-course application — This application is typically used on pavements that have a good cross section and ride, and the application works well over chip-seal roads, with the typical spread rate of 18 to 21 pounds per square yard. Terry Asphalt Materials utilizes Ontario Trap Rock to help the application retain a dark gray color.
  • Black Mat surface course — This treatment is a hybrid of micro-surfacing that utilizes Ontario Trap Rock and a mix design that is much softer than a conventional micro-surfacing mix design, and it provides a smoother and quieter pavement surface. Terry Asphalt has been applying this surface treatment in residential areas at a typical application rate of 17 to 22 pounds per square yard.

"We're one of the largest, more reputable asphalt emulsion producers in the Michigan/Ohio area and we not only perform Kent County's micro-surfacing work, but we also supply the emulsion they use on their chip seal projects," says Rusty Terry, who's in charge of Michigan sales and technical support for Terry Materials. "We've been applying approximately 400,000 square yards of slurry annually using a continuous micro-surfacing machine on large road projects and a (Bergkamp) truck-mounted micro-paver on smaller residential projects.