There's a lot that goes into building a bridge.

On Friday morning, the Times News visited the construction site just off the Mahoning Valley toll plaza to see what goes into replacing the two Pennsylvania Turnpike bridges that carry thousands of vehicles over Pohopoco Creek, Pohopoco Drive and Route 209 daily.New Enterprise Stone & Lime Company Inc. of New Enterprise, Pennsylvania, is the contractor for the $22.1 million project, which is slated to be complete by June 2016.Frank Walter, construction manager at the site, explained that crews are currently working on the abutments for one of the bridges."It's quite a coordinated effort," he said, noting that to make this project possible, the Pennsylvania Turnpike Commission, Pennsylvania Department of Transportation, Pennsylvania State Police, New Enterprise, and other local organizations had to come together to make the decisions that worked best for the area and the project.At 6 a.m., crews began pouring concrete into the nearly 30-foot tall framing that will become the abutment. Rock Hill Concrete from Parryville supplied the concrete.The men used a concrete pump truck, which pumped concrete through a hose connected to what looked like a crane arm raised over 30 feet in the air. This allowed crews stationed on top of the wall to place the hose into the frame and control the flow.Walter explained that they could only pour three feet of wall per hour to keep the integrity of the wall intact. If it was poured too quickly, the strength of the structure may be compromised.Once the concrete is poured the abutment must set and cure before steel beams can be placed on the structures.Three of the four piers and abutments have been completed to date.Next week, the first four beams are scheduled to be brought in and lifted onto the piers over Pohopoco Creek. The work will take place overnight since traffic is lighter at that time.Walter added that the bridge replacement must be completed in stages, and include night work to keep traffic flowing on the turnpike.He noted that once the first bridge is complete, the second bridge replacement will begin.That construction will be a little trickier though, because crews will not have access to staging areas like they currently do off Route 209. The second bridge construction access points will be from the turnpike.The turnpike ramp was closed today while crews worked on the project.The bridge replacement project began November 2013.