Three Hillman Composite Beam (HCB) bridges were constructed in Missouri as part of the Safe and Sound bridge replacement project. The “Show Me State” also seized this opportunity to gather additional test data to share regarding HCB performance. An integrated study was done to investigate the HCB in-service behavior. As part of the research, infrared thermal imaging was used to determine the filling of the arch in the beam. In addition, the University of Missouri Science & Technology study included load tests and comparison with theoretical data. Test results indicated that the HCB possesses excellent durability in relation to the expected weather conditions in Missouri.
Click here to view the Missouri report
Prior to building the first highly skewed HCB Bridge, the Virginia Department of Transportation wanted to better understand the behavior and capabilities of HCB. A full-scale test specimen, 49 feet long with three beams on a 45-degree skew was built and tested by Virginia Tech as part of a study for the Virginia Center for Transportation Innovation and Research (VCTIR). The study tested the components during assembly of the structure, followed by a fatigue study of the completed bridge. After the fatigue study was successfully completed, the bridge was cut into three single-beam structures (maintaining the concrete deck) for further testing. One of the three test specimens was tested to failure in bending, exceeding the predicted performance. The second was also tested to failure, except with 12 of the 22 strands in the bottom cut to simulate damage. The test showed that the “damaged” beam still maintained sufficient capacity, sustaining a load greater than an HL-93 truck. The third specimen has been sent to the U.S. Army Corps of Engineers to perform long-term corrosion testing. This series of tests also resulted in a more comprehensive shear limit state design methodology.
Report Coming Soon
As part of the Knickerbocker Bridge project, Maine DOT elected to fund additional laboratory studies to vet out the viability of HCB for mainline highway bridges. The work was conducted at the University of Maine, Advanced Wood and Engineered Composites where a full-scale HCB, complete with a 4-foot-wide concrete deck, was tested with 2,000,000 cycles of fatigue live loading before it was subjected to failure in bending at an Operating Rating of approximately 3.5. Prior to failure, the same beam was also subjected to an ultimate shear test and sustained a load equal to three times the design live load shear with an elastic response. Prototype beams for the High Road Bridge and Peckman’s Brook were also tested at University of Maine with similar results.
Click here to view the Knickerbocker report
With proof of concept from the Type 1 IDEA study, HSR-43 was initiated to go beyond the testing of a single beam and demonstrate that an entire railroad bridge can be constructed using HCBs. This Type 2 study was also conducted at the University of Delaware, Center for Composite Materials. The study included refining the manufacturing process, testing two 30-foot beams in the laboratory, and fabricating and installing a complete HCB railroad bridge. The final test was conducted with additional funding from a consortium comprising five of the seven Class 1 railroads in North America, including: BNSF, Canadian National, Canadian Pacific, Norfolk Southern and Union Pacific. On November 7, 2007, a train with 320 kip coal cars traversed the first HCB bridge in the world at the Transportation Technology Center Inc. (TTCI) High Tonnage Loop in Pueblo, Colorado.
Click here to view the HSR-43 report
The Transportation Research Board (TRB) Ideas Deserving Exploratory Analysis (IDEA) program was created to fund unsolicited technologies and help independent inventors bring their ideas to reality for the benefit of the U.S. infrastructure. HSR-23 was funded through the High Speed Rail IDEA division. This grant resulted in the design, manufacturing and proof of concept of the first Hillman Composite Beam. All of the laboratory work was conducted at the University of Delaware, Center for Composite Materials. On February 1, 2002, the first HCB was loaded to failure with an ultimate capacity nearly four times that required by code.