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Client standards keep retail parking lot
reconstruction moving
By Dave Morningstar
Rebuilding a parking lot is not generally a big challenge, but there are exceptions to every rule. The parking lot for the new Super Wal-Mart store in Burton, Michigan, is one of them.
“If the store wasn’t open, we could just remove the old parking lot and install the new one,” notes Ajax Paving Industries, Inc., Project Manager Jeff Wood. “But the store is open and is changing from a regular Wal-Mart to a Super Wal-Mart, and it will soon be open 24/7. That makes things a bit more complicated.”
Heavy-Duty Parking
Wal-Mart also has high standards. The parking lot is being reconstructed with 3C and 4C asphalt, materials more commonly found on high-traffic roads than parking lots. The 3C base is 3 inches thick, and it’s topped with a 2-inch wearing course of 4C, for a total thickness of 5 inches. Most asphalt parking lots are only 3 to 4 inches thick, and the materials used are not nearly as strong as the C mixes specified by Wal-Mart.
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Due to Wal-Mart’s high standards, the parking lot is being reconstructed with 3C and 4C asphalt, materials more commonly found on high-traffic roads than parking lots. |
“The difference between 3C and 4C is essentially the size of the aggregate,” explains Bob Farina, Project Manager at Ajax. “3C is typically used for the leveling course on highways and 4C for the wearing course. This is a very heavy-duty parking lot for a retail store.”
The general contractor, J. R. Heineman & Sons, Inc., Saginaw, Michigan, is responsible for removing the existing pavement, and then Ajax rebuilds from the grade up. The job is done in sections to maintain access to the store.
“We meet weekly,” says Wood. “And I usually have a couple of weeks notice to get things lined up for a new section. All the contractors on the job work well together, and we all know the schedule. That’s fine, and it works well, except that none of us have any control over the
weather.”
Despite the Rain
Clay doesn’t absorb water as well as other sub-grade materials, and the aggregate specified was 22A road gravel, a material that will not stand to take as much water as some other stone bases such as limestone. “So we suggested that the aggregate base change to 21AA limestone to help with the stability in the event of the forecasted rainy season,” says Wood. “The sub-grade is compacted so it doesn’t depress more than half an inch during a proof roll before you can place stone on it. Then the stone has to pass the same test before you can place the asphalt. With this change in the aggregate base material, we will have a better end product.”
The job was started in July 2006 and is scheduled to be completed in December. “It will be, one way or the other,” says Jeff Wood. “But it will be a lot easier if the weather cooperates.”
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| Ajax suggested changing the aggregate base to 21AA limestone, instead of 22A road gravel, to help with the stability in the event of the forecasted rainy season. |
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