Concrete arch set in stone

By Dawn De Busk

Staff Writer

A crew member with Wyman & Simpson, Inc. stands near the retaining wall. The future roadway will sit a few inches below the retaining wall. (De Busk photo)

NAPLES – The new road will perch just below the retaining wall, which now towers 16 feet above the passers-by who travel through the Naples Causeway on Route 302.

As daily commuters stream along, a transformation is taking place between the two retaining walls.

Last week, crews from Wyman & Simpson Inc. placed 530-square-cubic yards of concrete to create the arch for the Bay of Naples Bridge. By the end of the month, the wooden forms – which were built to hold the shape of the concrete arch – will be removed.

Crews put in a 10-hour day to get the work done on Wednesday, March 14. Twelve hours after the workers punched out and went home, 107,325 tons of concrete had set.

According to the general contractor, having the concrete arch completed is a sizable step toward finishing the bridge, which is scheduled to be done before the Town of Naples’ ribbon-cutting ceremony on May 18.

“It’s a big relief. It’s a huge relief. It’s a big milestone,” Superintendent Jeff Simpson said on Tuesday.

He added the construction project is “right on schedule.”

Also, the warm temperatures have been much more accommodating for the concrete’s strengthening process than March temperatures hovering near the freezing mark would have been.

“The weather was a help because it has been warm,” Simpson said.

“We have to maintain the concrete at above 50 degrees for four days, and above 32 degrees for the last three days,” he said, adding the current temperature for the concrete was 85 degrees.

In addition, for a week following the placement, the concrete must be kept wet. A garden hose has kept a steady stream of water on the concrete.

A work truck belonging to Wyman & Simpson, Inc. is parked between two retaining walls. The wall ranges in height from 15 feet at the arch to 5 feet toward the west end of the Causeway. (De Busk photo)

According to Maine Department of Transportation (MDOT) Resident Engineer Craig Hurd, if the concrete dries too quickly during the first seven days after the placement, it loses some of its strength.

Simpson said the concrete arch “is gaining strength every day.”

“As soon as the concrete reaches its desired strength, which is about 10 days” after the placement, the crews will remove the plywood forms, he said.

The concrete for the arch arrived in approximately 50 trucks for a total of 530 cubic-yards. According to Simpson, it is possible to calculate the weight of the concrete based on the fact that one cubic foot of the material weighs 150 pounds. There are 27 cubic feet in a cubic yard.

Hurd said the recent concrete placement was like a weight lifted off every body’s shoulders, but the de-stressor did not come about without some hard labor.

“There were trucks every 12 minutes for ten hours straight,” he said.

Meanwhile, subcontractor Grondin began drainage work and is continuing with the installation of underground fire suppression pipes. When those projects are done, Grondin will switch gears and begin building the new road.

“Grondin is coming back two weeks earlier than I thought they would – because of the weather. The frost is gone from the ground,” Hurd said.

Please follow and like us: