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Monday, November 10

Fredericksburg Road bridge in place

Texas Sterling Construction began sliding the Fredericksburg Road bridge at Medical Drive into place Saturday night around 10 p.m., and by 1:30 this morning the bridge was in place.

That 28-hour window makes the Fredericksburg Road bridge deck the fastest to be installed in the state of Texas. Ever. How is that possible?

A typical bridge deck takes several weeks to install - the support structures must be cast and built, then (after the concrete has reached sufficient strength) bridge support beams are set, and then the deck itself is cast and poured. Factor in excavation and other dirt work, and the chore can easily take weeks or months to finish, meaning traffic disruptions for an extended period of time.

Here the bridge was built off to the side without interrupting traffic. Over the weekend - a single weekend! - crews were able to dig out the area the bridge would cover and slide the bridge deck into place. The good news is things went off without a hitch. The first push was the stickiest (moving millions of pounds of concrete is always tough), with friction finally giving way for a jolt start of about 12-15 inches Saturday night. Then the bridge moved along at about 4-6 inches per minute until it was in place by 1:30 this morning.

The process involves pushing two 2-million-pound bridges into place with hydraulic jacks, with the bridge sliding along Teflon-lined plates lubricated with Dawn dish soap. This week crews will be tying the deck into the existing roadway on Fredericksburg Road, then marking the roadway and setting barrier.

The process of the bridge slide and installation has required the closure of Fredericksburg Road at Medical Drive. Texas Sterling says they should have the roadway reopened by the end of this week, if all goes well.

That would mean not only setting a bridge deck in place this fast, but having the roadway reopened in a single week - all the fastest marks in our state's history. The speed is made possible by a new-to-Texas process, brought to the state by Texas Sterling Construction.

Using more traditional means, this bridge placement and installation would take somewhere between 30 and 60 days.