Wednesday, January 6, 2016

New on-ramp bridge to I-205 in Vancouver taking shape

By Tamara Greenwell

The new bridge connecting Northeast 18th Street to southbound Interstate 205 in east Vancouver is one step closer to completion. On Thursday, Jan. 7, our contractor crews will pour the concrete that will form the bridge deck of the new on-ramp.

How much concrete is needed?
  • We'll use 500 cubic yards of concrete to build the bridge deck.
  • The total weight of the concrete for the new bridge is more than 2 million pounds. That's the weight of more than 100 elephants!

Baby elephant Nandi and mother Semba at the Reid Park Zoo in Tucson, AZ

You might remember that the bridge's massive steel girders arrived in September 2015. Since then,  our contractor used thousands of pieces of wood to craft a temporary mold on top of the girders, forming the deck of the bridge. Steel bars were then installed inside the mold which act as the skeleton of the new on-ramp.

Rebar inside the bridge deck

Underneath the bridge deck

Weather plays a big role in concrete installation. Insulated blankets, tarps and heaters are used to keep newly poured concrete warm if the outside temperature drops near freezing. Construction is typically done on dry days, as moisture also impacts how concrete sets. Crews act quickly to cover the freshly laid concrete with large tarps if a surprise rain or snow shower hits.

Snow covering the I-205 NE 18th Street
Interchange Project on Monday, Jan. 4

The work on the new bridge is far from complete. Our contractor will monitor the temperature of the concrete while it sets during the next 14 days. After that, we'll test the concrete to ensure it's able to support both its own weight and the weight of the traffic that will use the new on-ramp.

Construction work on the I-205 NE 18th Street Interchange Project

We anticipate opening the new interchange to traffic this fall. It will improve safety and reduce congestion on I-205 between State Route 500 and Mill Plain Boulevard.