Precast puzzle

Modules stacked eight levels high for Alabama jail

By Sandra Bearden

Think of it as a gigantic Lego project.

But the Madison County, Ala., Consolidated Justice Center's $25 million expansion is no child's game. Blocks for this project weigh between 50,000 and 70,000 lbs. and they're put in place with a 300-ton crane.

The precast concrete modules used in much of the Madison County, Ala., Consolidated Justice Center's $25 million expansion aren't unique for detention center construction. But they do represent a "first" for Dawson Builders of Rainbow City, Ala., and for the module vendor.

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"I understand from the vendor that they've never stacked precast modules more than four levels high," said Mike Wesson, Dawson's project manager. "This building will be eight modules high. Structurally speaking, though, we're putting a building on top of a building. We're stacking modules four high, adding beams, columns and supports, then adding another four-level stack."

The 252,000-sq.-ft., three-building project will add 913 beds to the center - nearly triple the number in the existing city jail. Dawson is using 171 precast modules for the jail expansion and a medical building. The third building will expand the kitchen, laundry, booking area and other support facilities and doesn't require modules.

Dawson is using modules manufactured by Fibrebond Corp. of Minden, La. The company is one of several that sell precast modules nationwide for use in prisons, storage facilities, schools, hotels and other buildings.

"We determine what size cells are needed and cast the flat panels making up each module at our plant," said Ritchie Reid, director of Fibrebond's Construction Management Department. "Then we bolt and weld the panels together to form the cells. For most projects, we produce custom sizes that can be incorporated into the site plan.

"Modules range in size from single cells to dorm size. Our cells are made from 125 lbs. per sq. ft. (psf), steel-reinforced concrete."

Fibrebond buys detention-grade doors and windows from other vendors and casts them into the concrete, making them tamper-proof. Floors are sealed, walls are ready for painting, plumbing and lighting are in, and equipment chases are installed for electrical, plumbing and security systems.

The company sometimes also installs furniture before shipping the cells, but Madison County is providing its own. Reid said the biggest selling point for pre-cast modules is ease of construction.

Pat Hair, construction manager for the project, agreed.

"We decided to use precast cells to save construction time," she said. "The Public Housing Authority of Huntsville is building the expansion, which will house both city of Huntsville and Madison County prisoners. The Madison County sheriff, who will supervise the facility, had seen modules elsewhere and liked the idea."

The site for the expansion is an old landfill, so the contractor under girded buildings with 146 caissons ranging from 40 to 60 ft. deep and then put in a grade beam system for module support.

As the building continues to go up, the contractor builds a floor slab, places two levels of modules, one of which is at a balcony level, then another floor slab. Between the fourth and fifth levels of modules, workers place more beams, columns and supports. Then they construct an interstitial floor, made of precast hollow-core panels, that houses the building's ductwork, water lines and plumbing equipment.

Levels five-eight of the modules repeat the process. Another interstitial mechanical floor is above the eighth level of modules. Topping the building will be a standing-seam metal roof.

In addition to Dawson Building, a major participant in the Madison County jail project is Ruffin Enterprises Inc. of Tuscaloosa, Ala. Besides installing the building's electrical systems and electronic detention equipment, Ruffin sets up and installs the precast cells.

"We furnish the crane and operator, unload the modules, do the shimmying, set the modules in place and do the electrical/electronics work," said Kee Hall, Ruffin's operations manager. "It all grew from a little involvement we had in a project several years ago. Now it's a market niche. All we do is jails."

Wesson said coordination is important in such a complex job with so many players involved - city and county authorities, subcontractors and others.

"It's a complex job," he said. "Coordination is essential."

Useful Source:

For more information about the uses of precast modules, go to: http://www.pci.org/index.cfm