Two spans across Interstate 84 in New York were replaced in two weekends using the ABC tool kit.

Ask Bala Sivakumar about his nearly 30 years in bridge engineering, and he dutifully recites biographical information. But ask him about the need for accelerated bridge construction (ABC), and, suddenly, there's excitement and passion in his voice.

"Everyone agrees with the concept, but it's a question of inertia," he says of the industry's acceptance of ABC. "Getting buy-in is the thing I spent lots of time on. But it's easy [to promote] because I see the benefits."

He plumps for ABC in general and the ABC tool kit specifically. The tool kit was developed under the Transportation Research Board's two iterations of the Strategic Highway Research Program.


Sivakumar, director of special bridge projects with HNTB Corp., led development of the ABC tool kit, which contains standardized plans for modular components, erection concepts, construction specifications and other data that can be applied to a wide variety of projects.

The tool kit has proven itself in two full field demonstrations, the most recent of which was the New York State Dept. of Transportation's $10.2-million replacement of two spans across I-84 in Putnam County.

Performed on separate weekends in September and October 2013, the project successfully applied the tool kit's guidance for lateral-slide design and construction techniques. A team led by Yonkers Contracting Co. completed span demolition and replacement in just 20 hours, despite heavy rains.

Bill Moreau, chief engineer of the New York State Bridge Authority, says it's worthwhile to standardize ABC approaches using the tool kit, as it "allows agencies to tailor the concepts to the job and specific needs. You don't have to reinvent the wheel every time you do an overpass," Moreau says.

The Vermont Agency of Transportation also drew on the tool kit to replace three bridges damaged by Tropical Storm Irene in September 2011. "We had to fast-track designs and plan development in order to obligate federal funds within one year of the flooding event," says Kristin Higgins, project manager for VTrans' ABC program. "The ABC tool kit gave us the jump start we needed."

Born in Sri Lanka, Sivakumar came to the U.S. in 1980 to earn a graduate degree in structural engineering and has worked with bridges ever since. Developing the ABC tool kit has taken up much of his time for the past six years, he says. When an agency decides to try it, a one-day training workshop is included.

Now, having worked with a half-dozen states, Sivakumar is confident that the tool kit is gaining traction.

"I hope that, in the next five to eight years, we can hit 15% to 20% of all bridge replacement projects," he says. "We'll see [ABC] blossom."