Tilikum Crossing Bridge Wins Green Design Award for use of Slag Cement
At 1700 feet in length, Tilikum Crossing, Portland Oregon’s "Bridge of the People," is the first bridge of its kind in the U.S. A cable-stayed bridge, with two piers in the water and two on land, Tilikum Crossing is designed to carry metropolitan area express (known as MAX) light rail trains, buses, street cars, cyclists, and pedestrians, but not automobiles. The word Tilikum is a from the Native American language Chinnook Wawa and means "people, "tribe" and "relatives". Tilikum symbolizes people coming together, and conveys connections they will make as they ride, walk, run and cycle across this beautiful bridge.
Slag cement was used in the high performance concrete on the bridge to increase durability. The mix design for the girder sections required 3500 psi at 18 hours and 8000 psi in 56 days. There were no low strength tests on this project. The mass concrete contained 50% slag to lower heat of hydration. The use of slag contributed to achieving the lighter color desired by the designer without using white cement. The reliable supply and performance of slag cement consistently provided specified concrete plastic properties. In addition, use of slag cement, a recycled material, reduced the carbon footprint of the project, contributing to achieving the desired green-design, sustainable-development objectives of the Portland, Oregon community for this mass-transit centered structure. .
The Slag Cement Association (SCA) presented the 2015 Project of the Year Awards on April 18th during the ACI Special Session “Use of Slag Cement in Notable Structures, Part 2” at the ACI 2016 Spring Convention Milwaukee, Wisconsin. The Awards recognize projects for excellence and innovation in concrete using slag cement. Nine projects received 2015 Awards in the categories of Architectural Design, Concrete Durability, Green Design, High Performance, and Sustainability.
Project credits: TriMet, Owner; Donald McDonald Architects, Architect; T.Y. Lin International Group, Engineer; Kiewit Infrastructure West Co. , Contractor; Ross Island Sand & Gravel, Concrete; Ash Grove Cement Company, Slag Cement.