More than ever before, stretching transportation-construction dollars is the order of the day as agencies contend with limited resources and rising construction costs. The solution for many facilities is pavement overlays, and increasingly agencies are turning to concrete overlays because of their performance and value.
On the boulevard
A prime example of an overlay project can be found in Royal Oak, Mich., just north of Detroit, where Coolidge Highway serves as a vital multiuse facility that traverses seven communities.
The two- to six-lane facility is both a boulevard that moves traffic to and from nearby Woodward Avenue (M1) and a major route to I-75 through Royal Oak and Troy, said Kerry Sutton, P.E., director of engineering for the Michigan Concrete Paving Association, Southeast Michigan. Originally constructed in concrete during the late 1920s, the pavement was rehabilitated a number of times with asphalt pavement. The original structure is still in place and carrying traffic, currently about 30,600 average daily traffic (ADT) today, according to Matthew Callahan, P.E., civil engineer with the city of Royal Oak’s engineering department.
In the early 1980s, the pavement was both rehabilitated and widened in some areas with concrete pavement, many sections of which are still carrying traffic today, some 25 years after placement.
Last year, the city of Royal Oak repaired and replaced some of the panels with concrete in an approximately 4 lane-mile stretch from 13 Mile Road to 14 Mile Road. The recent rehabilitation project involved approximately 7,500 sq yd of 9-in., hand-poured concrete, although there were some areas where 8-in. concrete panels were cast in place. All told, only about one-third of the original panels were repaired or replaced, according to Steve Lampton, senior project manager with the paving contractor, Florence Cement Co. Inc., Shelby Township, Mich.
Although commercial traffic accounts for only about 5% of the ADT, Callahan said, “there are a lot of manufacturing plants, as well as a Consumer’s Energy facility, so we have a lot of semitrailer traffic and heavy vehicles moving along the roadway.”
The good life
“We got some pretty good life out of the concrete pavements,” he said, adding that prior to the repair and replacement project different options were evaluated, including asphalt with concrete curb-and-gutter, as well as the overlays that were selected based on both cost and performance criteria.
“I also believe we get better control of concrete compared to asphalt,” Callahan said, adding that for the recent repair and replacement project, “we wanted the paving materials to be consistent, but we also wanted the roadway to have a consistent look, too.”
He added that one of the major challenges of the job was the significant grade changes in the area.
“There were areas where significant fill was used, in some cases up to 5 ft,” Callahan said. He added that a limited amount of slab lifting was used on the project, but most of the sections were tied too much to the asphalt base materials.
Still, he said, the city is planning to use foam-based technology on other pavements that would be good candidates for this restoration method that lifts panels to grade, fills voids and extends the life of the pavement.
There were some cracked and shattered panels, mostly from heaving attributed to the grade conditions and use of gravel, according to Lampton of Florence Cement.
“The bond breaker commonly used in the early 1980s was gravel versus the 1-in. asphalt interlayer currently used today,” he said, adding that the use of asphalt overlays years ago also presented some challenges, so “we had to muscle them out and fill them with gravel.”
This overlay is expected to extend the life of the pavement for many years, thereby avoiding total reconstruction, as well as the frequent repairs and maintenance typically associated with asphalt pavements.
Pavement overlays are increasingly popular with agencies across the country, and given the rising costs of oil and asphalt, as well as the energy costs associated with both construction and repair cycles, concrete overlays are proving to be the right choice for a growing number of agencies concerned with cost, performance and sustainability.
Information for this article provided by the American Concrete Pavement Association, Skokie, Ill.
