A lot more bridge to see

From ODOT-If you have not been by the Willamette River Bridge project recently, make the time to do so. Even during the rain, snow, cold and windy conditions this winter and spring, a lot of progress was made. The graceful arches crossing the river are the most noticeable feature of the new southbound Interstate 5 bridge. But be sure to notice the steel supports and falsework from the north bank of the river to the south, where the new bridge joins I-5. Construction workers can now walk from the north to the south end of the bridge, above ground. Crews are forming and pouring the final support beams for the bridge deck. In preparation for paving the bridge deck, forms are built on top of the beams, and rebar is installed and tied. Already, portions of the deck have been poured on the north side of the river as well as sections on the south side joining I-5. Over the next couple of months, crews will pourt the rest of the concrete to complete the deck on the south side of the river. The deck over the river, supported by the arches, is the largest pour and cannot take place until all the north and south portions of the deck are complete. With the arrival of spring and better weather, take time to look more closely at the new bridge from one of the pedestrian paths near the project. There's a lot more bridge to see! The southbound bridge is on schedule to open to traffic in early fall.

The first deck pour for the southbound bridge

From ODOT- This past Friday was an exciting day on the project- it was the first of many deck pours. Contractors began pouring the concrete surface that motorists will drive on, completing the roadway and the surface that supports the future bridge rail. Crews are starting on the approach span on the north side of the new bridge. Next, they’ll move to the south end of the project and work their way north.





We are using a new type of concrete that has less hazardous materials (silica) and is less expensive. For a good and durable surface, we need good weather conditions—not raining or too cold. Wind is also an issue. Our crews will use hand-held instruments to measure the wind conditions--evaporation rates must be continuously monitored.



The task is very labor intensive. Crews use a vibrating machine to consolidate the concrete and remove any air pockets and then a roller moves back and forth to level the concrete for a smooth ride.



The concrete is cured for 14 days. Crews help the process by laying down wet burlap and soaker hoses and covering the new deck with plastic. It’s like a greenhouse to keep the concrete wet and warm enough to build required strength as it cures.



I was able to visit the project and took some video of the process. In addition to the equipment mentioned above, you will see the containment precautions used when transferring the concrete from the original trucks to the concrete pump truck. I learned that the contractor has to wet the wood forms before the concrete is poured so the wood doesn’t stick to concrete when the forms are removed.