Department of Civil, Construction, and Environmental Engineering

Two civil engineering graduate students spent much of their time last fall in Boone County, Iowa. Why? Samantha Hockerman and Ryan Bowers were involved in a research project to determine the feasibility of using an accelerated bridge construction system in Iowa. The result: They’re finding quicker, safer ways to build and repair bridges across the state.

In rapid construction systems, sections of bridges are built off-site, and later transported and installed on location. Hockerman and Bowers worked on a bridge at 120th Street over Squaw Creek in Boone County—about 20 miles northwest of Ames.

Hockerman developed and implemented tests on precast bridge elements, and designed the internal instrumentation in the deck panels and instrumentation on the post-tensioning tendons. She also documented the construction process with the assistance of F. Wayne Klaiber, professor of civil engineering; Terry Wipf, professor of civil engineering and structural engineering division leader; and Jim Nelson (BSCE 1997, MSCE 2005), an engineer with the Iowa Department of Transportation (DOT). Bowers conducted many tests, including lab tests on the precast bridge deck panels.

Hockerman says time is the biggest benefit of using rapid construction techniques. “Bridges can be closed for a few weeks instead of a few months,” she says. “It also typically means less environmental impact, safer conditions for construction workers, and safer conditions for the driving public.”

Although this technique has been around for decades and is used especially in Europe, engineers in the United States and Iowa have only recently become more interested in this process. “This is where the industry is headed, without a doubt,” says Hockerman. “For heavily trafficked roads and bridges, this type of construction can greatly reduce the amount of economic loss due to closures. As traffic keeps increasing, this technology will only become more valuable.”

Recently, Hockerman’s and Bowers’ work was recognized when the Boone County bridge received an Iowa Quality Initiative Structures Award. It won the Merit Award for a concrete beam bridge on a local system constructed in Iowa between 2004 and 2006. The Iowa Quality Initiative Structures Award program recognizes structures built in Iowa that demonstrate superior quality of workmanship in their construction and design.

The rapid bridge construction research was sponsored by the Federal Highway Administration, Iowa Department of Transportation (DOT), the Iowa DOT Highway Research Board, and Boone County.