What Is That?

This photo shows a post-tensioning duct on the Valley View Street bridge, which is being reconstructed as part of the WCC project.

The post-tensioning duct consists of the three vertical holes, which you can see in the center of the picture. The ducts will be threaded with steel tendons — which look similar to the steel bars seen protruding from the wall on the left — and pulled taut.

The process, called post-tensioning, is a method of reinforcing concrete with high-strength steel strands, typically referred to as tendons. It provides reinforcement for the new bridge by strengthening the concrete and making it more resistant to environmental stress.

For more info about post-tensioning, check out this week's construction highlights, available at http://www.octafiles.net/wcc102411.pdf.

Safe driving!