Magazine article Corrections Forum

Advantages of Precast Concrete Construction

Magazine article Corrections Forum

Advantages of Precast Concrete Construction

Article excerpt

OVER the past decade, preLcast concrete module construction has become a commonly-accepted way of building jails and prisons. Precast modules offer an unmistakable advantage: an overwhelming sustainability edge, a way to shorten up the construction process - and provide an overall cost savings.

What are these specific advantages? What are some of the differentiating factors that define precast module vendors? And how has the current economy affected construction?

Sustainability - or the ability for a correctional facility to be energy efficient and kind to the environment over its lifecycle - is a huge issue today. A recent study showed a "dramatic energy savings" using insulated precast walls, says Graham Walker, VP and CFO of Fibrebond, a Louisiana company in the precast corrections business since 1989.

The study, conducted by concrete-insulation maker Thermomass, reported a "a 12 percent to 25 percent actual saving of utility costs" as a result of this type of construction. Because concrete is considered a thermal mass it helps absorb heat during the day, keeping warm air outside in the summer and inside during the winter. The range, he explains, depends on the local climate.

As far as sustainability, the U.S. Green Building Council allots 20 to 28 LEED points for precast construction, Walker continues. These potential points are credited for a range of environmentally-friendly measures, from optimizing energy performance to materials reuse. Because precast modules are constructed offsite, the owner can be virtually be guaranteed earning extra credits for reduced site impact. If the manufacturing plant is within a 500-mile radius, the owner garners a local materials point.

'THEY NEED IT YESTERDAY'

In today's economy, projects may wait years to be approved and are sorely needed by the time funding is available. "Now, when it goes, they need it yesterday. Scheduling has really tightened up," explains Walker.

Precast construction speeds up the process. Concurrent activities like earthwork and foundations can be done on the site while cells are being built offsite at the manufacturing plant, which is more crucial in colder locales. The further north the project is located, the shorter the construction window, points out Ed McGee, business development manager, Fibrebond. "On a job we bid in North Dakota, to be able to produce in a temperaturecontrolled factory really helps."

Erecting the building is like using building blocks, continues McGee." We can erect 20 modules or 40 cells in a day." Compared to conventional CMU construction, it's "an awesome overall reduction in time."

Up to 4,000 precast modules are produced per year in Fibrebond's 350,000sf PCI-certified manufacturing facility in La. Its module is unique in that it is six-sided, which includes four sides, roof and floor. A Y wall separates the cell on left and right. The company says that this design gives it flexibility in adjusting width, depth and height.

It is costly to adjust a monolithic form for a limited run of cells, notes Walker. "Having dimensional flexibility is inherent with our product." Architects and owners then don't have to limit their dimensions to other's requirements. For instance, special needs or isolation cells ideally have different dimensions from standard cells; these modules offer that sort of flexibility.

For a Lincoln County, Neb., jail with fairly small runs - 32 modules all together - Fibrebond was asked to provide single cells on the ends to provide an extended mezzanine balcony. "It was easy to do," says Walker.

The company was also awarded a project in Hidalgo County, N.M., with only 11 modules, two of them front chase triple cell modules. Fibrebond was able to meet the jail's requirements without costly custom fees. "For us to fabricate that is much less expensive than with a monolithic pour; that is an expensive proposition," concludes McGee.

LARDER RUNS

Oldcastle Precast Modular Group in Telford, Pa. …

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