This checklist incorporates precautions one producer found necessary when casting and shipping box beams for Ohio DOT.
Don Bosse, plant manager for Prestress Services of Melbourn, Ky., focused on profit-and-loss issues. Prestress Services' first experience with HPC bridge work required an overall assessment of operational capabilities at the pre-bid stage and a few modifications during actual production of 115 1/2-foot-long beams. What emerges is a checklist you should look at when bidding a similar project.
For pre-bid planning be prepared for a lot of involvement by engineers and researchers. Don't bid for more than your casting beds can handle. Pay attention to anchorage details, and check the route and jobsite before transporting the beams. Look carefully at the construction scheme and how it will affect your erection plan.
In beam production, run trials of the mixture, cast test beams, and allow time for instrumentation. Be aware of the difference in diameter between this higher-capacity strand and the strand you are accustomed to working. Allow for additional labor to install and stress the strands. Silica-fume concrete may require extra laborers and extend the mixing cycle. Placing the concrete may require modifications and take more time and labor than anticipated. Be prepared to make additional concrete test specimens to determine properties of the fresh concrete. Be aware that curing time may be different from that of the test beams.
By carefully reviewing this checklist, you may avoid surprises as the actual project unfolds.
The article includes a "Portrait of a long-span bridge," a 54-year-old steel girder bridge on Route 22 over Crooked Creek in Gurensey County, Ohio.
Keywords: high-performance, bridge, Ohio, Prestress Services, University of Cincinnati, long, span, bed, HPC, strand, transport, erect, stress, Guernsey County, Crooked Creek