There are few environments in the world more caustic and corrosive to bridges than coastal regions adjacent to oceans and brackish estuaries. It is almost a foregone conclusion that bridges of conventional materials will experience accelerated deterioration and limited service lives in these locations. Many of these are also small bridges owned and maintained by local government agencies that often reconstruct these bridges with internal resources.
Virginia Department of Transportation (VDOT) recognized that the Hillman Composite Beam (HCB®) provided a unique bridge solution that could not only be constructed with smaller equipment, but also would provide a sustainable solution to survive the aggressive environmental conditions of Colonial Beach.
VDOT seized an opportunity not only to replace a decaying bridge with a superior technology, but also to employ rigorous testing of the HCB design and constructability features to further validate the benefits of this technology for system-wide deployment. Prior to the project’s construction, a full-size HCB bridge incorporating the 45-degree skew was constructed and tested by the Virginia Center for Transportation Innovation and Research (VCTIR) at the Thomas M. Murray Laboratory at Virginia Tech.
The 2,000,000-cycle test with HL-93 design live loads proved the “real-world” HCBs were consistent with the design methodology even on a severe skew. As part of this program, two of the HCBs were tested to failure, including one with more than half of the tension reinforcement removed to simulate a damaged beam. This test showed that even with half the bottom flange removed, one HCB was still able to support the weight of an entire HL-93 truckload.
Erected in February of 2013 by Bryant Contracting, the Route 205 Bridge in Colonial Beach, Virginia, comprises a single-span bridge with eight HCB units installed above Tide Mill Stream at the Potomac River. The existing bridge had narrow headroom above the water with negative freeboard. Since the abutments were still serviceable, VDOT saw an opportunity to reduce the project cost further by using a lightweight, corrosion-resistant HCB bridge that also allowed for reuse of the existing substructure without additional piling.
By placing the HCB units side-by-side, the 4-foot (1,220-millimeter) wide top flanges eliminated the need for deck forming between the beams. Concurrently prefilling the compression reinforcement at Coastal Precast Systems in Chesapeake, Virginia, further maximized the benefits and expedited the construction time of this prefabricated bridge system.
Project Specs:
HCB Piece Weight
Owner: Virginia Department of Transportation (VDOT)
Contractor: Bryant Contracting
Completion date: March 2013
Project Sheet: Click here for downloadable PDF version