Below-surface problem

So how thick is a brandnew road? About 22 inches.

First is the existing ground known as the subgrade base. Excavators spent the better part of nine months last year essentially moving dirt from one place to another to create the bottom layer of what will become the new highway. Almost every area has about 5 feet of earth to serve as the subgrade base.

On top of that will be a 6inch layer of 2A stones with a maximum size of 1.5 inches, followed by a 4inch layer of permeable asphalt to help with drainage and then 12 inches of concrete.

The plan was to scrape off the top few inches of dirt this spring and use what’s left as the subgrade base. But when inspectors ran filled tri-axle trucks over the scraped land to test it, they found it was spongy in numerous places, indicating the land underneath is wet and unsuitable for paving.

As a result, inspectors marked soft spots with red paint and ordered crews to remove the wet material and replace it with dry dirt.

“If you have a spongy bottom, you can’t dry it out,” said Mr. Kohlmyer, picking up an exposed clump of clay that was about the consistency of Play-Doh.

“It’s underneath something, so it’s never going to dry. You can’t build on it. You have to take it down to the wet, take it out and replace it, then pile the top back on.”

The turnpike has about a dozen inspectors on the site to test the surface and make sure it’s ready for placing the top 22 inches. Gary Patterson, a field inspector for GAI Consultants, said it’s a tedious process to dig down about 3 feet to find the wet material and remove it, but it’s not unusual.

“After all that rain we had, it made everything wetter than it’s supposed to be,” he said.

Mr. Kohlmyer said the problems with the subgrade aren’t anyone’s fault — except maybe Mother Nature.

“We moved over 5 million cubic yards,” he said. “It’s going to happen a little bit. It’s part of the process.

“Hopefully the road lasts years longer because we make sure it has a proper base.”

Critical bridge

The poor weather also slowed down some of the progress on another important part of the project, the bridge over Little Raccoon Creek.

Bridges at Quicksilver Road and Candor Road are in various stages of completion, Quicksilver almost finished except for paving because it will be difficult to get machinery in later and Candor less far along because its finish isn’t as time sensitive.

But the project schedule calls for Little Raccoon to be one of the first items to be paved. That’s because it literally will serve as the bridge for dozens of trucks from the mobile concrete plant to the rest of the road.

Rain didn’t interfere much with placing the bridge’s massive precast concrete beams, reinforcement bars or other items to prepare the bridge for paving.

But it did prevent pouring concrete to fill the area known as “the blockout,” which essentially holds the ends of the bridge together, until Thursday.

The blockout is an area about 2 feet wide between the ground and the beginning of the bridge beams and holds the expansion dams, a rubber material used to accommodate the bridge’s expansion and contraction as the weather changes.

While another crew placed reinforcement bars in the middle of the bridge, a concrete truck dumped its load a couple of yards at a time into a concrete bucket, a cone with a nipple on the bottom like a funnel. A crane lifted the bucket and suspended it above the blockout.

One member of the fiveman crew pushed the lever to drop the concrete into the blockout while the others worked the mixture into the space and smoothed it out to eliminate air bubles.

If contractors can get the bridge finished on time, Mr. Kohlmyer said, they likely will begin working extra shifts when paving begins so they can build more float.

“They want to work ahead. The same [poor weather] is likely to happen in the fall.”