Precast reduces construction time from 1-1/2 years to 4 months.
Back in 1925 when this quaint one lane bridge was built over the Scantic River in Connecticut, the Ford Model T was at the height of production. The bridge has since been rehabilitated 3 times and described as having advanced deterioration. Clearly this bridge had seen better days and its time had come and gone.
The new 82 foot single span replacement bridge would have to blend in with the natural beauty of the forest and scenic historic river area. Tectonic Engineering & Surveying Consultants P.C., the engineers of record, preformed a study to determine the type of bridge that would best suit the area. A prestressed adjacent box beam superstructure was recommended and designed for the bridge with a cast-in-place concrete substructure
According to Jeffery A. Scala, P.E. with Tectonic Engineering, they performed a construction time analysis that lead them to propose that the “design be revised to utilize 100% precast elements to shorten the construction duration to one season”, 4 months instead of the original 1-1/2 year proposal. This would reduce the traffic detour time as well as eliminating winter construction and the river’s flood issues that occur in the spring. Building with precast concrete also reduces the amount of disturbance to the surrounding forest and river because much of the work is done off site making it less intrusive and easier to protect the area. It would become Connecticut’s first fully precast bridge.
One of the time saving benefits of precast concrete is that the preparation work can be done at the site while the precast pieces are in production. Dailey Precast, LLC manufactured the 71 pieces needed for this project in an indoor controlled environment. Special forms were designed to make the exposed wing walls look like a masonry stone wall, which makes the bridge blend with the historic feel of the surrounding area. Scala applauds the speed of which a precast bridge can be constructed saying that “once the elements were cast and the site preparation was ready, it only took 2-1/2 weeks to fully assemble the bridge.”
The just completed bridge is two lanes with sidewalks and bike shoulders. It contributes to the scenic beauty of this historic area and will provide decades of service for those who drive, walk or bike in this magnificent area. |