Hybrid composite beams installed ahead of schedule in Illinois bridge

HC Bridge Maine LLC has completed an Illinos bridge that uses high-strength, high-endurance hybrid-composite beams.

HC Bridge Co. LLC (Wilmette, Ill. and Brunswick, Maine), developer of a hybrid-composite structural beam concept that can be used for accelerated bridge construction, recently announced that construction of the High Road Bridge has been completed over Long Run Creek in Lockport Township, Ill. Completed three months ahead of schedule and now open to vehicular traffic, the bridge is the first permanent highway installation of Hybrid-Composite Beams (HCBs), developed by HC Bridge. The firm is headed by the beam’s inventor, John Hillman — HC stands for Hillman Composite beam. The concept was patented in 2000, and since then, beams have been tested for railroad bridge applications as well.

The existing High Road Bridge, constructed in 1935, had outlived its useful service life and was categorized as both structurally deficient and functionally obsolete. In order to reduce future maintenance costs, the replacement structure, designed by Teng & Associates Inc. (Chicago, Ill.), with whom Hillman is affiliated, used the HCB technology.

HCBs comprise three main subcomponents — an outer fiber-reinforced plastic (FRP) shell, a compression reinforcement and a tension reinforcement. The compression reinforcement consists of concrete that is pumped into an arch conduit within the beam shell. The tension reinforcement consists of high-strength steel prestressing strands that run along the bottom flanges of the beam shell. The encapsulating FRP shell protects the beam from salt corrosion and provides additional structural support.

For this 57-ft/17.4m, single-span bridge, six 42-inch-deep HCBs, spaced on 88-inch/2.23m centers, support a conventional 8-inch/203-mm-thick reinforced concrete deck. According to Hillman, the bridge was constructed exactly the same way as a conventional concrete or steel bridge, but the stronger, lighter and more corrosion-resistant HCBs will provide real advantages to the Lockport Township Highway Department.

Manufactured by Harbor Technologies Inc. (Brunswick, Maine), the HCBs are approximately one-tenth the weight of a typical precast concrete beams for the same span length. The huge weight reduction reduced shipping and erection costs: All of the beams for the High Road Bridge were shipped on a single truck; six trucks would have been required to transport the same number of precast concrete beams. Erection required only a 30-ton crane instead of the 150- to 200-ton crane that is necessary for precast concrete beams. Partial funding for the project was provided by a $250,000 (USD) grant from the Federal Highway Admin. (FHWA) through the Innovative Bridge Research and Design (IBRD) Program.

As part of the IBRD program and prior to installation in the High Road Bridge, the HCBs designed and constructed for the High Road Bridge underwent extensive testing at the Advanced Engineered Wood and Composite (AEWC) Center at the University of Maine in Orono. The first live load test of a full-scale HCB Bridge was conducted at the Transportation Technology Center Inc. (TTCI), near Pueblo, Colo., in November 2007. It was subjected to a battery of tests that included trials involving a full-size locomotive and 26 coal cars. The HCB prototypes in the railroad bridge were subjected to loads approximately seven times as heavy as the design loads for the High Road Bridge. As a result of the successful project, HCBs now are being considered for bridges in Maine as well as future Illinois bridge projects.


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The Texas Dept. of Transportation (TxDOT) recently installed over a drainage ditch in Refugio County a new bridge that incorporates composite beams, replacing a single-span, steel girder bridge. Located 35 miles from Corpus Christi, the 50-ft/15.4m long, 32-ft/10m wide bridge is the state’s second to use