With aging roads and heavy traffic, the need for concrete overlays is there. That was a message delivered at the Michigan Concrete Paving Association's (MCPA) recent open house event for the Coolidge Highway construction project in Oak Park. Coolidge Highway is being overlaid with concrete.
"When you're scoping a concrete overlay project, look at it like you're scoping an asphalt overlay project. Whatever you have to do for an asphalt overlay project, whether it's repairs, corrections or changes, you would have to do for a concrete overlay project," MCPA's Kerry Sutton, P.E., director of Engineering-Southeast Michigan, said.
"In many cases, such as the Coolidge Highway project where you have old concrete underneath, you might not have to do as much repair with the concrete overlay. The separator layer is there and you're filling in and packing a lot of the old joints anyway." The maintenance requirements for concrete overlays are minimal.
"When the product goes down, it looks like a brand new road. With concrete, you have the advantages of high load-carrying capacity and no rutting," Sutton said.
Florence Cement, Inc., of Shelby Township, is the prime contractor for the approximately $4.8-million, 2-mile long, five-lane Coolidge Highway project. The project began in May. The roadwork will be completed in November. Some landscaping enhancements will be done in the spring of 2008.
The existing asphalt pavement and curb is being milled off. Some full-depth concrete pavement repairs and joint repairs are being done. A 1-inch asphalt separator layer is being placed on the existing concrete and a 6-inch deep P1 modified concrete mix is being placed on top of the asphalt separator.
The only portions of the project that are full-depth reconstruction are areas where the new concrete is being tied into existing pavement. This is being done in order to accommodate grade changes for the concrete overlay, according to Steve Lampton, project manager for Florence Cement.
"P1 modified concrete is a well-graded, denser concrete mix. It lends itself to higher strength as well as a lower permeability. The saltwater doesn't affect it as much in the winter," Lampton said.
Lampton pointed out that one problem with P1 modified is that the materials for the mix must be shipped from Northern Michigan because they are not available in Southeast Michigan, which can cause a delay in the construction schedule.
"The only long-term solution will be if this mix is used more often, the aggregate suppliers in the Metropolitan Detroit area will stockpile this material more," Lampton said.
Material quantities on the project include approximately 20,000 square yards of pavement removal for the tie-in points; 61,000 square yards of asphalt cold milling; approximately 3,500 tons of asphalt for the separator layer; 60,000 square yards of concrete overlay; and 11,000 cubic yards of concrete overlay.
Subcontractors for the project include: Lois K. Contracting (cold milling); Doan Construction (concrete curbs, sidewalks, driveways, and colored stamped concrete); G.M. & Sons (concrete curbs, sidewalks, driveways, and colored stamped concrete); Big Foot Construction (structure lowering and adjustments); and Motor City Electric (traffic signal upgrades).
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