One big 'Lego project'

Concrete segments for the Brandon Parkway are cast at the Port of Tampa, and will be joined later to form the elevated road.

By null, Times Staff Writer
© St. Petersburg Times
published April 25, 2003

PORT OF TAMPA - On 25 acres with a prime view of the downtown skyline, more than five dozen workers are churning out the first of 3,000 concrete segments that will fit together like Legos to form the middle span of the $350-million Brandon Parkway.

The 70- and 80-ton segments will form a 6-mile elevated bridge, the hallmark of the 9-mile reversible expressway aimed at easing the commute between Brandon and downtown Tampa.

As workers at the Port of Tampa pour concrete for the segments, other workers are toiling in the median of the Lee Roy Selmon Crosstown Expressway, setting up piers that will serve as the elevated bridge's foundation.

Officials at the Tampa-Hillsborough Expressway Authority decided to cast the segments at the port because it shortens the project's construction schedule and eases the disruption of traffic along the Crosstown Expressway.

"When you're not doing it on sight, you won't close lanes," said PerryDawn Brown, the authority's spokeswoman. "That's really important, because we are operating a business and don't want to inconvenience our customers, which in this case are Crosstown users."

Chris Stack, precast manager for PCL Civil Constructors, which is building the elevated bridge, said casting the segments at the port also results in a "better product, because we're in a controlled environment, away from traffic and the elements."

The precast technique debuted in Europe in the 1950s, and is often used for bridges built over water because it is easier to haul segments than to build them on site. In recent years, precast bridges have gained favor in the United States. The technology was used on the Sunshine Skyway Bridge over Tampa Bay in the mid 1980s. Others in Florida include the Seven-Mile Bridge in the Keys and the Ringling Causeway Bridge in Sarasota.

But the Brandon Parkway's reversible bridge stands out for its size. At 3,000 pieces, this is the largest project ever tackled in Florida by PCL Civil Constructors.

"This is just huge," Stack said. "You typically see this (technique) used on a much smaller scale. Three-thousand segments is just a big job."

PCL recently completed the half-mile Ringling Causeway Bridge, which consisted of fewer than 500 precast segments. When they finished producing the Causeway pieces in the fall, most of the workers moved from Port Manatee to the Port of Tampa, Stack said.

They cast the first segment for the reversible expressway in late February, and have since tucked away another three dozen. When all 11 casting cells are operational by the beginning of May, 100 workers will be at the casting yard to produce 45 of the 9-foot-long segments each week.

It will take about 20 months to make all 3,000 pieces, which are being stored on a tract that takes up half the casting yard, said PCL yard superintendent Gary Fenton.

At a cost of $10,000 each, producing the concrete segments accounts for almost 10 percent of the expressway's $350-million price tag.

Each bridge segment starts with 10,000 pounds of steel that are tied together to form a sort of cage. The cage takes about one day to build, and is then moved by crane to one of PCL's 11 casting cells.

About 38 cubic yards of concrete is poured into the cell, to set overnight. In the morning, wire cables running through the segment are pulled tight. At the "finishing station," workers grout the cables with a cement paste for added strength.

The expressway will need to be strong: By the time it opens in the spring of 2005, the Tampa-Hillsborough Expressway Authority projects as many as 100,000 cars will use it each day.

It will give commuters a one-way, non-stop toll road that has none of the delays associated with on-ramps and toll booths.

In the mornings, three lanes will carry traffic west from Brandon to Tampa. Before evening rush hour, the lanes will reverse direction to bring downtown workers back home to southeastern Hillsborough County.

In mid-May, PCL will start loading the concrete segments onto five flatbed trucks for transport and assembly at the expressway.

Most of the segments are hollow, and roomy enough inside for a few people to walk around. The hollow pieces running through the reversible bridge will provide a place where companies can test out traffic control and transportation technologies.

For now, the expressway is like a puzzle-in-the-making: Each completed segment is waiting in a corner of the PCL casting yard, carefully identified according to its exact location along the toll road. Because each segment is cast to match the neighboring piece, there is no room for error.

"There's a male and female part, and they've got to fit together," Brown said. "It's just like a big Lego project."

- Shannon Colavecchio-Van Sickler can be reached at 661-2443 or