Two historic bridges, both decades old and in disrepair, needed to be replaced in Bastrop County, Texas, near the town of Smithville. The Texas Department of Transportation (TxDOT) was tasked with finding acceptable replacement structures for proper levels of safety and to blend them into the natural environment.
The existing steel trusses could not handle normal heavy traffic loads. Both of these original bridges had been downgraded to a "load rated" status, though one was salvaged and relocated for pedestrian use.
There were two key determinations to a potential solution: that the bridges be made out of weathering steel and cast-in-place concrete pavements and that they be replaced quickly to maintain traffic flow.
TxDOT turned to Contech to provide a natural, rustic look and truss shape to match the original bridges and to accomplish the task in short order with its Steadfast Truss Bridge solutions.
The Kovar Road Bridge, just southeast of Smithville, was a 24-ft-wide by 100-ft-long connector bridge spanning the Barton Creek. The project consisted of first carefully taking out the old steel truss bridge in order to relocate it to the City Park in Smithville to preserve its heritage in a safer setting.
The bridge was then replaced with a new Connector Steel Pratt Truss bridge. Contech and Steadfast custom-matched and designed the bridge in record time. They had to take into account the extra concrete requisites of the structure, because it was imperative for the replacement bridge to maintain the original 2% cross slope on the concrete bridge decking.
The Watts Lane Bridge spanned the Cedar Creek, just south of the town of Cedar Creek, Texas. It is a busy roadway east of state Rte. 21, midway between FM 812 and FM 535.
The 28-ft-wide by 100-ft-long span bridge was replaced by a weathering steel Keystone-style bridge that is set at a 15° skew and has an 8-in.-thick concrete floor. It replaced a smaller steel-truss bridge, which had a wooden plank driving surface. The new bridge allowed TxDOT to widen the proposed roadway and increase flow area without affecting the creek.
TxDOT worked with Dean Word Co. of New Braunfels, Texas, to deliver the projects on time. Dean Word Co. used one large crane at each site to erect the floor beams for the two 100-ft-long, two-piece trusses.
It took only one week to assemble and erect the structures. Once the trusses were assembled, the contractor was able to set them in place and field-bolt all the floor beams to them in just over a day. The remaining portion of the week was for installing the stay-in-place forms and rebar and pouring the concrete deck. They will now carry HS20 Highway Loading status.