The Twisp River Bridge Replacement project is a single 197-foot span bridge in the North Cascade Mountains in Washington State. At the time of construction, new WSDOT W95PTG (7.87 ft) girder sections were used. The girders were delivered in precast segments and post tensioned in place composite with the bridge deck. The girder concrete used was High Performance Concrete (HPC) with 28-day strength of 8 ksi. The girder closure pours used 5 ksi concrete, where typical closure pour concrete used 4 ksi. The Twisp River Bridge has made a positive lasting impact on the environment by removing piers from the water.

This project led to the innovation of new prestressed spliced girder sections and the use of High-Performance Concrete (HPC). This increased WSDOT's available inventory of standard prestressed girders available for use.

PCI-Certified Precast Concrete Producer:

Concrete Technology Corporation, Tacoma, WA

PCI-Certified Erector:

Post Tensioning Subcontractor: Avar Construction System, Inc.

Architect:

WSDOT Bridge & Structures Office, Olympia, WA

Engineer of Record:

WSDOT Bridge & Structures Office, Olympia, WA

Owner:

WSDOT, Olympia, WA

Contractor:

One Way Construction, Inc., Sedroy Wooley, WA

Key Project Attributes

• This project led to the innovation of new prestressed spliced girder sections and the use of High-Performance Concrete (HPC).

Project/Precast Scope

• 197-foot span bridge