SDOT: High bridge repair: Post-tensioning is over; preparation for the final stage of epoxy crack injection and carbon fiber wrapping

SDOT installed the new structures for directional signage on the West Seattle Bridge.

Photo SDOT

Information from the Seattle Department of Transportation

Earlier this week we announced that we had finished tensioning the post-tensioning cables inside the deck. This major construction milestone was the final step in a long and complex process to install a new post-tensioning system on all 3 spans of the bridge structure.

Hydraulic equipment inside the beam
We use hydraulic equipment to tighten the metal strands of the post-tensioning system. This process compresses the concrete in the deck to make it stronger and prevent future cracks. Photo SDOT

With the bridge concrete compressed and stronger than ever, we can move on to the next item on our reopening checklist, which is to begin the final phase of epoxy crack injection and fiber wrapping. of carbon. This process will take several weeks.

Bridge Repair Checklist

This week we started surface preparation for epoxy crack injection on the bridge girders. This is the process of filling small cracks with an epoxy compound using a high pressure pump to help prevent existing cracks from expanding. It took until the structural concrete was compressed by the new post-tensioning system before sealing these specific sections of cracks on the bridge.

We also made additional progress on major maintenance this week. We installed a new overhead sign structure and made additional concrete pours for replacement signs on the west approach to the bridge.

Bridge sign structure

As part of major maintenance work, we are replacing overhead signage structures on the West Seattle Bridge. These structures contain the directional signage you see when crossing the bridge.